A&Q about 350Z
Q:
OK. so $3 gas is here to stay , and I'm gettin' tickked.
What if I took and old Subaru (justy, etc.)
and hooked an electric motor to just the rear drive and left the front on gas .......
Anybody to comment?
The optomist has no brakes, the pessimist has no motor.
I need a good parts car.........
A:
For the all the money you spend doing that you could just invest your money in some mutual funds in energy. The return will help you pay for fuel expenses.
You can also find yourself a car with a small diesel engine. Those kind of cars get better mileage than any hybrid car. Don't buy into the marketing hype. Hybrids are nothing more than cash makers for Japanese manufacturers. Small diesel cars get way better mileage in typical daily driving.
1971 240Z
"Fear is exciting for me." -Ayrton Senna
A:
In some places diesel fuel is even higher than regular though.
Chris
76 280z --- turbo in the works
A:
Think of it this way. If diesel costs 5% more than regular gas BUT the diesel car gets 30% better mileage, then how is it more money. Yes, the fuel costs more per fill up, but you don't fill up as often so the savings are still there.
1972 240Z 4-speed, header, 3.54 R200, Crane XR-3000 Ignition, 280Z tach, Tokico Blue Struts, Suspension Tech Springs, Poly Bushings. Visit me at my website for your custom EFI & restored Datsun parts
A:
Get a diesel truck and make your own fuel... You can make 40 gals in 48 hours and the only down side is the start up cost! But after you make about 2000 gals then you will start to save big money in fuel cost...
77 280Z with SBC, 700R4, Vette C4 IRS W/11.5 rear disk, Centerlines 16x9.5 W/BF G 245x45ZR Comp T/A Rear and 15x7 Ft W/BF Goodrich Euro 225x15 on ft. Soon to have Coleman 12.2x1.25, x-drilled, zinc plated, Rotors W/Billet Outlaw 4000. Z U V8ter
A:
Well, it's not the power plants in a hybrid, it's the controls. You need a damn good full time management system. Also, you can use MORE energy to lug around the car with undersized engines. That is why the Toyota hybrids get less mileage on the highway than their full gas cars.
A:
Top Gear reviews the Prius:
The conclusion they reach is the same we've come up with here.
1980 280ZX, now with L28ET and Megasquirt 'n Spark Extra
Pallnet Fuel Rail, KYB Gas-A-djust Shocks, Advan A048 Tires
ACT Clutch Disc & Pressure Plate, Steel Braided Brake Lines
A:
Not to mention that hybrids won't save you any money at all until the 5 year mark of ownership. Even GM acknowledges that hybrids are just marketing tools:
http://www.leftlanenews.com/2006/07/21/lutz-gm-building-hybrids-for-good-press/#more-3454
"General Motors Vice Chairman Bob Lutz said in an interview this week that GM doubts the benefits of hybrids, but must build them to improve its public image. "Hybrids are technologically of doubtful benefit, and expensive, but necessary from a political and public relations point of view," Lutz told Just-Auto."
Post Edited (Jul 23, 11:26am)
A:
If you just need something to putt around town, I wonder when we're gonna start getting the European Diesels.
Such as the VW Lupo Diesel, +70 mpg on the highway.
That is insane....
Mario
1976 280Z - Dad's Z (turbo swap?)
1978 280Z - Stock Rebuild | 5 Speed | Twice Pipes | Gutted
1982 280ZX - Turbo | MSnS-E | 5 Speed | Large NPR IC
BROKE: Will build computers, webpages, networks, MS units, troubleshoot computers for money
A:
The price of a new Hybrid can't hold a candle to my paid for 34 mpg Honda. If it takes 5 years for the Hybrid to offset the price premium in gas mileage savings, I couldn't even fathom how many decades it would take to make it worthwhile to trade-in the Honda.
I believe, as soon as we get low sulfur diesel in the US, we'll be able to get the European diesel's.
However, I'm not sure you can run low sulfur diesel in a motor designed for high sulfur, so the time frame for wide spread adoption/availability will be interesting to watch.
When my paid for '99 Durango blows up, I was planning to get the 'new' Dodge Ram 2500 Contractor's Edition. It was a Cummins Turbo Diesel/Electric Hybrid that could use the electric motor as an integrated electric generator with NEMA outlets right in the rear of the bed. This would have been great for going to the track to run the compressor and air tools and anything else that needed electrical power.
Unfortunately, Dodge backed away from it due to quality issues coming out of their Mexican manufacturing plant (go figure!) and are only offering it for fleet sales with no private sales...
I'll just have to make due with the 24v Makita cordless impact wrench...
72 WooHoo!! In good shape too...
72 Rolling Chassis (RB or LS1?)
80 NA SCCA ST2/CP (Car + Tree = Dead)
82 NA 3.0L the rust monster got it
82 ZXT 3.1L, 25psi! Hit in the right rear. ;(
83 parts car
92 TT Sold! ;(
02 Looking for an '03 made in '02
Post Edited (Jul 23, 4:30pm)
A:
Thanks for that link Chaoticmass, that was a good watch! Pretty much everything I talk sh!t on the Prius about seems to be right!
85' 300ZX NA
86' 300ZX Turbo
88' 300ZX Turbo
89' 300ZX Turbo
300ZX Turbo Project
A:
No diesel car will hold a candle to a comparable hybrid in town as far as mpg goes.
The real benefit (and it IS very real) of hybrids is the ability to recapture energy during braking.
Lots of hype, positive and negative, but still hybrids will way outperform non-hybrids under most combined driving conditions, even if they don't exactly live up to the EPA sticker.
A:
Not to say current hybrid models make actual economic sense overall!
BTW, there was once a gasoline non-hybrid for sale in the U.S. that got 50 mpg!
The real enemies are size and weight and Cd. If the automakers would work on those, we'd have much better mpg without any expensive batteries.
A:
"hybrids will way outperform non-hybrids under most combined driving conditions"
Not from what I've seen.
ONLY way for a hybrid to get better mileage is in full time stop-and-go traffic. If you are really driving, the hybrid is no better than any low displacement car (and is actually worse than many).
Basically in a hybrid you have an electric transmission for a gas engine. That's all they are, an electric transmission.
Post Edited (Jul 24, 8:40am)
A:
You're right that on the highway hybrids have little to no advantage. It depends on your usage. What "really driving" means is up to the end-user. If a decent percentage of your driving is in-town, there should be a fuel-mileage benefit to the hybrid. Whether that makes a good choice for overall expense is another question...
Current hybrid automobiles do not have an "electric transmission" for a gasoline engine. The gasoline engine is capable of driving the car with no electric assist whatsoever. I *think* what you're thinking of would be a pure series hybrid like a diesel-electric train, where only electric motors drive the vehicle, with electrical energy supplied by diesel generators.
What hybrid cars do to increase fuel mileage is:
1) allow use of a much smaller gasoline engine while maintaining the same short-term acceleration capacity
2) recapture energy normally lost to heat in braking
#2 can amount to a LOT! Which is why hybrids can get better gas mileage in the city than on the highway.
A:
My sister's Metro gets 40+ and she bought it used for $3K. With that, where is the incentive to buy a hybrid?
Low sulfur diesel should be widely available to the U.S. by the end of this year since EPA regulations for it came into effect June 1st. And there's no need to worry about the loss of lubricity as a lubricating agent will be added in.
3 Zs, 1 "Rusty", 4 more to go
A:
"What hybrid cars do to increase fuel mileage is:..."
I mean that power is converted from gas to electric so the electric is a transmission of that power. A small engine is a complete compromise that ONLY works in a narrow region. The engine is too small to run the car hard and too large to run the generator continuously. If you get the car out of it's "niche", then it's inefficient.
Back to a homade hybrid, chances are even slimmer of getting anything "better" by do ing a conversion. Chances are higher that the end "product" will be worse in every aspect.
A:
Too large to run the generator continuously?!
A controller dictates how much power from the engine goes into the batteries via the motor/generator. The gasoline engine can't be "too large" to run the motor as a generator! The motor/generator simply takes as much as it needs and no more.
Small engine is a compromise that ony works in a narrow region?
The idea is that you run a smaller engine at closer to its power capacity most of the time, and when you need a lot MORE power you get it from the electric motor. The electric motor makes torque over a very broad rpm range, so this to some degree makes up for a possibly peakier smaller-displacement gasoline engine.
Agree that even at $3/gal, a home-made hybrid is probably a very bad idea for 99.9% of us. Perhaps wdnnkl is the 0.1% kook who can pull it off and make it work for cheap! But then he probably wouldn't be asking about the idea's feasibility on ZCar.com I guess...
A:
"The gasoline engine can't be "too large""
If you speak about efficiency, then yes, it CAN be too large. That's why it's always a compromise design. Once you compromise, you have to accept crappy mileage in all conditions except low speed stop-and-go.
A:
Electric engineer David Arthurs spent 40 hours of his time and $1,500 to come up with....
lawnmower engine-together with all the electrical components necessary for the conversion-fit comfortably in what was the Opel's engine compartment.
The layout of the new drive system.
The sports car's outside appearance as well as its curb weight-remains virtually unchanged.
Dave's hybrid electric automobile "drives" like a normal vehicle . . . but squeezes 75 miles from each gallon of fuel!
With the price of gasoline already out of sight, just about everyone is scrambling for a way to squeeze the last possible drop of energy from each precious gallon. However, David Arthurs-of Springdale, Arkan sas-probably couldn't care less ... because he has designed and built a car that can travel 75 miles or more on just four quarts of the expensive liquid! What's his secret? Well, Dave's Opel CT is a hybrid electric vehicle. That is, the car is driven by an electric motor . . . but that powerplant's "juice" is generated with the help of an ordinary, fuel-stingy lawn-mower engine! Now the fact that the system works isn't really surprising. What's amazing is that the crossbreed hookup performs so well ! According to David, the Opel has not only a virtually unlimited range (when driven prudently), but also a top speed of 90 miles per hour . . . and emits a minimum of pollutants as it tools along the highway. Better yet, the car can-if need be-run on its batteries alone for short in-town hops . . . and will never be "stranded" as long as there's fuel in the "on board" generator!
WORLD WAR II TECHNOLOGY
Mr. Arthurs is the first to admit that there's nothing "new" to the system he's developed . . . in fact, all the technology incorporated into his design has been available for about 35 years, just waiting for someone to put two and two together and make the whole thing work. "I began researching the idea for a hybrid electric auto about a year ago. There wasn't much information to be found on the subject, so I designed a system from scratch. In about a month's evening-and-weekend time, I had the car finished and running." Surprisingly enough, the project didn't cost a fortune, either. Because the vehicle's components are either standard "off the shelf" hardware or available as reasonably priced military surplus, the conversion to "hybrid drive" only set Dave back about $1,500. By the same token, any necessary replacement parts are easily obtainable . . . and a good deal of the equipment can be "scrounged" rather than purchased new.
HOW IT WORKS
In essence, David has utilized a small gas lawn-mower engine to drive a generator, which-in turn-supplies the vehicle's drive motor with electricity. To do so, he first removed the Opel's original power-plant and installed a 400-amp DC motor/ generator (actually a jet engine's starting motor) in its place. (Since there's no need for a clutch in Dave's setup, the stock unit was pulled out and the main shaft of the drive motor was fastened directly to the input shaft of the car's transmission.) Then, to provide a consistent source of power for this motor (and to supply an energy storage bank), the engineer installed four 12-volt, heavy-duty automobile batteries-in series-which are "fed" by a 100-amp generator that's run off a 5-horsepower lawn-mower engine. Of course, other components (such as relays, charging diodes, rectifiers, and an additional motor speed regulation circuit) are necessary to keep input and output power within optimum limits-and to allow full control of the vehicle at all speeds-but these are standard electrical parts which have been available for years. The engine-driven generator can handle the demand from the main motor up to speeds of about 50 miles per hour. The "stored" energy in the batteries comes into play at higher velocities, giving extra kick for passing and climbing hills. To guarantee that the charging system isn't overworked . . . Dave has rigged up a regenerative braking circuit which- in effect-turns the drive motor into a generator, to feed the batteries when the vehicle is decelerating. (This not only takes advantage of normally wasted energy, but also saves wear and tear on the car's conventional braking system.) Since the Opel's "stock" cooling apparatus has been removed, two small thermostatically controlled electric fans provide ventilation to the motor and generator as required ... while the gasoline engine is, of course, air-cooled by design.
GROWING PAINS
Any project fresh off the drawing board has its share of problems, and the Opel hybrid was no exception. When David pressed the accelerator for the first time, he got a 300-amp surge which melted his relays. So he searched his graduate texts for the answer ... and finally found it in-of all places-an old high school physics book: A pulser was necessary to "chop" the current flow and prevent a heavy initial draw to the drive motor. As Dave explains it, "The motor will always have full voltage and full current, but the pulser makes it 'think' the voltage and amperage are cut down to about 1/4 of what's actually available. With this gadget-which is simply a combination of a reworked car generator and an old fan motor-I can keep the draw within limits and effectively control the car's acceleration . . . without sacrificing the maximum current or voltage that's necessary for high-speed driving. I could have achieved the same results with a commercially available FCR control ... but one of those units would have cut my power slightly, and cost in the neighborhood of $800! I can build my own device for about $25, and I can fix it myself if it breaks!"
AND IT'S REALLY PRACTICAL!
Actually "piloting" the hybrid electric isn't much different from motoring in any conventional automobile. There's a slight hum from the electric motor, but the sound is certainly no more obvious than that of an internal combustion engine at speed. And-unlike many electric vehicles-the little Opel' really has some get-up-and-go . . . due to the fact that the converted car is only about 50 pounds heavier than its original 2,100-pound weight. Of course, some folks will question the idea of shifting without a clutch . . . but with the fully synchronized gearbox-this doesn't prove to be a problem at all (and the motor could be run through a conventional clutch with few complications). As far as the driving range is concerned, Dave points out that-if driven carefully the car can travel unlimited distances (as long as the generator engine continues to function) . . . because of the fact that the motor has a low draw at cruising speeds: only .23 amps at 1,800 RPM. Since the Briggs & Stratton engine turns at a fixed rate and can generate 100 amps at about 28-1/2 volts, normal driving presents no problem. Hot or traveling in a very mountainous area-could, however, tax the car's charging system . . . but even these demands don't pose much of a problem, because the batteries can be brought from a 1/4 charge (the effective "dead" state, with a built-in safety factor) to a full charge in only 15 minutes. David Arthurs' electric Opel sounds almost too good to believe . . . and best of all, its circuitry can probably be adapted to just about any vehicle on the road today! It is true that small, lightweight cars are more easily "hybridized", but this same system will also work in a heavier auto . . . it could even be upscaled to suit one of the large American models. In short, Dave has succeeded in doing-for a lot less money-what countless government-funded researchers have failed to accomplish: building a passenger car that uses a minimum of energy. Now all he has to do is burn "homegrown" alcohol fuel in his generator engine . . . and Mr. Arthurs will have the most economical set of wheels in town! EDITOR'S NOTE: If you're discovering that you can't keep up with the high price of gasoline-and are willing to do something about it-you'll be pleased to know that MOTHER has made some special arrangements with David Arthurs. A set of detailed, easily understood plans will soon be available that will allow the average "backyard mechanic" to convert a conventionally powered automobile to hybrid electric drive. MOTHER's plans package includes schematic drawings, a components list-complete with manufacturers' names and part numbers-and a materials list . . . all put together in a fully explained, easy-to-follow packet. just send your name and address-along with $15.00-to Mother's., Plans, Hybrid Electric Car, P.O. Box A, East, Flat Rock, North Carolina 28726.
http://www.motherearthnews.com/Alternative_Energy/1993_June_July/1993_Update__Dave_Arthur_s_Amazing_Hybrid_Electric_Car
And for Tony D:
http://www.motherearthnews.com/DIY/1980_May_June/Hybrid_II
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A:
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A:
BS.
No way in hell that a loose fitting slide valve 5hp lawnmower engine with a flaky carb will get that kind of mileage. Only way would be if he plugs the car in at night.
A:
Hybrid sez: "If you speak about efficiency, then yes, it CAN be too large. That's why it's always a compromise design. Once you compromise, you have to accept crappy mileage in all conditions except low speed stop-and-go."
Of COURSE it's a compromise design! There are tradeoffs/compromises made in EVERY automobile!
The point is, you use a smaller gasoline engine than you would have to if you didn't have an electric motor to add power during peak demand. So the gasoline engine will be smaller than the equivalent non-hybrid's gasoline engine. So it will be more efficient. Which may or may not make up for carrying additional weight in the form of batteries during highway cruise conditions...
A:
Forget the hybrids...a brand new Honda Civic Hybrid is rated at 49 mpg (city) and 52 mpg (highway), so my 1991 Honda CRX HF got me a 'real world' not an EPA rated 50 mpg. Do the math I drove it for 352 miles, it got empty so I went to the gas station to fill it up for ~$23 (at $3.05/gallon) because it has a 7 gallon gas tank, so 352 miles with 7 gallons that's 50mpg! And that was with both city and highway miles...oh and by the way I bought it for $2200! :)
I love my 350Z and my Datsun 510 but they both suck a$$ when it comes to mileage so I drive my 62 HP beast around more and more enjoying the savings.
-2003 350Z Enthusiast Stage 0
-1971 Datsun 521 Inline 4
-1970 Datsun 510 w/KA24DE
-1991 Honda CRX HF
(62 HP and 50 MPG BEAST!!!)
A:
"So the gasoline engine will be smaller than the equivalent non-hybrid's gasoline engine. So it will be more efficient"
Dan,
Smaller does NOT mean more efficient.
Like the article that Blue posted with a 5hp lawnmower engine.
A low compression, loose fitting, carbureted engine WILL NOT get great mileage no mater what it's doing. I can push a lawnmower and it will go through a quart of fuel in 5 miles (~20mpg). If the mower was pushing me, it's get less than that.
Putting an inefficient engine on a generator will NOT make it efficient.
A:
Hybrid77, here is what I get from the Opel GT article:
The author states:
45mph requires 200A @ 36V = 7,200W
(this is the power needed to counter the rolling resistance and wind resistance of the Opel at 45mph)
Since 1HP = 746W(electrical)
The car will require 9.7HP gas motor to maintain 45mph assuming perfectly efficient conversion of mechanical (lawn mower) to electrical (electrical motor) to dynamic (to wheels)
The claims seems reasonable if the Hybrid design also used the batteries to make up for the missing energy (since he only has a 5hp motor and needs more than 9.7hp to maintain 45mph).
The only data needed to calculate the fuel consumption is the fuel draw of a 5hp motor at full load. I found this info online which is close:
6.5 HP Honda GX200 OHv
3.8 quart fuel tank
1.5 hours at full load (6.5HP)
2.3 hours of run time at 1/2 load (3.25HP)
So the Honda will consume 1 gallon in 1.58hours at full load and 2.42hours at 1/2 load.
At 45mph a 6.5HP Honda car at full load would have traveled 71.1 miles on one gallon so 71mpg (assuming the batteries did the rest of the work) .
At 45mph a 6.5HP Honda car at 1/2 load would have traveled 108.9 miles on one gallon so 109mpg (assuming the batteries did the rest of the work) .
This makes the claim of 75mpg seem reasonable even with an old 5hp motor from the 70's.
I'd like to see a small aerodynamic F1 style single seater commuter car with a tiny motorcycle motor in the back and mountain bike wheels. Since one only needs ~12hp for city commuting it would be perfect. Getting the coefficients of drag down along with weight will do the trick.... hmmm I wonder if a sea kayak mounted on a suspension based on cobbled mountain bike frames would be a start for an off the shelf base platform LOL
Honey, I'm off to work!
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Post Edited (Jul 25, 8:58am)
A:
"So the Honda will consume 1 gallon in 1.58hours "
Driving
------------
The honda will consume 1 gallon in 2 hours.
The car will go (2 hours)x(45mph) = 90 miles.
That will give you 90 miles per gallon.
Recharging
--------------
Now when you STOP the car, the engine has to stay running flat out to recharge the batteries. Since the batteries did about 3.5 hp work per hour, the charhing will take 1 hour flat out to top them off. That is an extra 1/2 gallon assuming a perfect world.
Total Gas used
-------------------
(1 gallon driving)+(1/2 gallon recharging)/90 total miles = 60mpg max theoretical Not bad but when you throw in the real losses when recharging the batteries, you're down to around 40mpg.
Conclusion
---------------
Any smal gas engined car can get 40mpg at 45mph all day long. I get 40mpg in an old Honda 1.4L automatic at 65mph.
A:
The article talks about using an external changer, not the lawn mower motor, however I see your point: all energy must be factored into the cost, not just the liquid fuel.
I think for the world's energy consumption cycle to be "renovated" we can only go this way:
SOURCE: Nuclear Plants
Consumable Energy Medium: Hydrogen and Electrons
Energy Extraction Methods:
1. Nuclear>>Heat>>Steam>>Turbine>>Electricity>>Distributed over revised power grid
2. Nuclear>>Heat>>Steam>>Turbine>>Electricity>>Hydrogen (from electrolysis) Distributed over revised piping and containers
Key Processes and Parts:
Nuclear: Thorium Reactors (Cleanest Fission)
Hydrogen Generation: Electrolysis of Water using electricity
Hydrogen Fuel Cells
Battery exchanging at new "service stations" (like propane tank exchanging)
More electrical machinary and retrofitting into combustion based machines
CO2 scrubbers for the atmosphere
High Altitude Ozone generators
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A:
Funny how those external chargers will increase the "gasoline" mileage...
Yea,
Nuke is the only way to make enough electricity if cars are converted to some kind of electrical instead of liquid fuel.
A:
Me: "So the gasoline engine will be smaller than the equivalent non-hybrid's gasoline engine. So it will be more efficient"
Hybrid77:
"Dan,
Smaller does NOT mean more efficient."
Two equivalent designs, the smaller-displacement will be more efficient. Less frictional and pumping losses. Obviously, Toyota and Honda aren't using side-(not "SLIDE")-valve lawnmower engine level of technology in their hybrids' gasoline engines, they are no doubt more efficient than a similar-design larger engine with the same max power/torque characteristics as the hybrid engine/electric motor combination.
As for the lawn-mower powered hybrid mentioned above, it takes more than 5hp to drive that Opel at 50mph, so I'd take anything else mentioned in that article with a HUGE grain of salt anyway.
A:
"Two equivalent designs, the smaller-displacement will be more efficient. Less frictional and pumping losses"
A small 0.5 cubic inch V8 will have a higher percentage of frictional losses and higher percentage of pumping losses than a 327 cubic inch V8. Garanteed.
Since there is very little friction inside of an engine, efficiency comes from the burn, not from the absolute displacement.
A:
What can I say, I think you're wrong. [edited :)]
A 2.0 liter engine vs. a 2.3 liter of similar design parameters will get better fuel economy. 2.0 liter Mazda3 gets 28/35 mpg, 2.3 liter gets 26/32.
To deny that smaller engines get better fuel economy is to deny reality.
The internal engine losses are not huge loads on the engine, but at cruise operation they do make a difference in mileage. And larger engines (of similar design and configuration) have greater losses.
Post Edited (Jul 26, 8:37am)
A:
Like I said, compare a 1/2 cubic inch V8 to a 327 cubic inch V8 to see that smaller does not mean more efficient.
It's NOT the displacement, it's the efficientcy of the fuel burn. A modern 350 cubick inch V8 with fuel injection put in a 260Z will get the same highway mileage as the orininal 158 cubic inch 260z carbed engine in a 260Z.
A:
The losses in the 1/2 c.i engine will obviously be FAR less than the losses in the 327.
A modern 350 w/ f.i. vs. an old carbed L28 is hardly a valid comparison.
Smaller engines generally will have lower internal losses. Why is that so hard to understand?
Obviously, efficiency of the fuel burn is hugely important. That is not to say that nothing else is!
A:
"The losses in the 1/2 c.i engine will obviously be FAR less than the losses in the 327"
It's portpotioanally more so it's a less efficient engine. Efficiency is what we are talking about
"A modern 350 w/ f.i. vs. an old carbed L28 is hardly a valid comparison."
Sure it is. It's a beautiful example of WHY fuel burn is more important than displacement as far overall efficiency.
"Smaller engines generally will have lower internal losses. Why is that so hard to understand?"
Why? Because displacement is not proportional to internal losses that's why.
A:
I'm talking about the car's efficiency at a given speed. With a smaller engine of similar design parameters, a car WILL get greater fuel mileage with a smaller-displacement engine, PERIOD.
Your 1/2 c.i. vs 327 c.i. thought experiment doesn't hold water and isn't relevant anyway. Show me some experimental results and I'll consider them.
Saying that fuel burn is important (duh) doesn't mean that internal frictional and pumping losses are negligible. Again, your point is not pertinent to the discussion.
"displacement is not proportional to internal losses"? That's kinda backwards.
I never said that internal losses were proportional to displacement, only that a larger displacement engine (of similar tech/design/configuration) will have greater losses. 20% greater displacement doesn't necessarily mean 20% greater losses.
A given car at a given hwy cruise speed will get better fuel mileage with a smaller-displacement (again, same tech, etc...) for a couple of reasons:
1) smaller engine has lower internal losses
2) smaller engine will be operating at a higher percentage of its output capacity, thus will be operating at a higher efficiency. (general rule for piston aircraft engines is that peak efficiency is at 75% power).
A:
Dan,
You are the perfect example of what's wrong with discussions about hybrids. You keeps changing the parameters. Stick to ONE parameter and the issue can be discussed.
Efficency (the topic) for a given set of physical vehicle parameters is NOT goverend by engine size. That is the trap seen in the example of small engine hybrids. They get WORSE economy on the highway than larger displacement gas engined non-hybrids. The smaller displacement engine does not make a more efficient SYSTEM.
Just because ONE parameter is optimized doen not mean that the SYSTEM is optimized. That's the trap, the half-truth, the hybrid car lie.
A:
Geez, Hybrid, I really don't think you've been paying attention at all.
As usual, you are the one who is confused and is "changing parameters". I think you know just enough to try to add to the confusion, but still don't have the big picture figured out for yourself. You seem to WANT hybrids to be inefficient and ineffective in every way. I don't hesitate to agree that they don't make overall economic sense for most. But there ARE certain limited benefits.
"They get WORSE economy on the highway than larger displacement gas engined non-hybrids."
PLEASE show me an example of a non-hybrid that gets better highway mileage than a reasonably-near-equivalent hybrid.
FWIW, the only reason we got on this engine size vs. efficiency tangent is because YOU said:
"If you speak about efficiency, then yes, it CAN be too large. That's why it's always a compromise design. Once you compromise, you have to accept crappy mileage in all conditions except low speed stop-and-go."
All I did was say that hybrids allow for a smaller internal combustion engine which should be more efficient at highway cruise, then you went all screwy and reversed yourself, saying "smaller does not mean more efficient", in direct contradiction to what you said above! WTF?!
Here is what I have said in this thread. Tell me how I'm "buying into the hybrid lie":
"The real benefit (and it IS very real) of hybrids is the ability to recapture energy during braking.
Lots of hype, positive and negative, but still hybrids will way outperform non-hybrids under most combined driving conditions, even if they don't exactly live up to the EPA sticker."
"Not to say current hybrid models make actual economic sense overall!
BTW, there was once a gasoline non-hybrid for sale in the U.S. that got 50 mpg!
The real enemies are size and weight and Cd. If the automakers would work on those, we'd have much better mpg without any expensive batteries."
"You're right that on the highway hybrids have little to no advantage. It depends on your usage. What "really driving" means is up to the end-user. If a decent percentage of your driving is in-town, there should be a fuel-mileage benefit to the hybrid. Whether that makes a good choice for overall expense is another question..."
A:
"All I did was say that hybrids allow for a smaller internal combustion engine which should be more efficient at highway cruise"
That is EXACTLY where they DO NOT have an advantage. The Toyota Prius gets EPA 60 city and 51 highway. Owners say they get 49mpg consistantly. I've personnaly measured over 50mpg many times with a Honda Civic 5 speed. Highway cruise offers NO advantage.
"hybrids will way outperform non-hybrids under most combined driving conditions"
LOL, a hybrid that is compared to a similar sized/engined non-hybrid car is at a disadvantage because the hybrid is HEAVIER than the normal car. Real world acceleration, hills, and just lugging around that extra battery weight and extra engine weight will take it's toll. Like you said, WEIGHT is the enemy for mileage. A similar sized and displacement gas car without all the hybrid weight will be more efficient when driven, garanteed.
Post Edited (Jul 26, 6:06pm)
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Your anecdote proves nothing. Have you tried your EXACT driving profile with a Prius or Civic hybrid? Anyway, I've repeatedly said the hwy advantage would be minimal, with benefits from running a smaller gasoline engine somewhat offset by the increased rolling resistance from the additional weight.
Throw in some around town driving, and forget it. Your Civic won't even get CLOSE to Prius or Civic hybrid mileage (even allowing that their actual mileage won't come close to their EPA-rated mileage). The weight disadvantage of the hybrid is overcome by its ability to recapture energy during braking. You seem to be insisting that hybrids do WORSE vs. non-hybrids in city driving, when clearly the opposite is true.
I'm totally in favor of the manufacturers building much lighter-weight non-hybrid mileage champs. That seems to me to be the more elegant (and cheap!) solution. But I do acknowlege that there IS a niche in today's market for hybrids.
Post Edited (Jul 26, 7:03pm)
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Hybrids are ONLY better in heavy stop-and-go level city mild temperature daylight niches.
Once you start DRIVING, the regenerative brakes do nothing, the added batery weight is dead weight, and running all the A/C radio and lights will means that the little engine never is off.
Anecdote? Just read up on the masses of Prius drivers that drive their cars and are complaining. My Honda (50mpg highway) and my Acura (40mpg highway, automatic) on the highway with the A/C blowing. It's not an anecdote when it's real world. EPA estimate of 51 on the highway is not real world and IS LESS for the hybrid.
Seriously, equal size car and equal displacement will always go to the regular gas car when the car is in motion (driving). Apples to apples the hybrid is heavier, more expensive, more required maintenance, less efficient in real driving.
Top Gear reviews the Prius:
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Also,
Not sure WHY you call it annecdotal since my Civic and the Prius both have the same size gas engines. Why would they not get roughly the same highway mileage? Same long flat road, same size car, same size engine, same air resistance, same mileage.
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It's anecdotal because you didn't do a scientific comparison, you've only "tested" one car, yours. You're comparing your actual results wiht your civic against what others are getting driving their hybrids under undoubtedly different circumstances. Drive the exact same profile with a Prius or Civic Hybrid and then you'll have the beginnings of scientific evidence.
It wouldn't surprise me if they do get about the same highway mileage, fwiw.
As for regenerative braking, OF COURSE it only benefits driving profiles in which stops are semi-frequent! Stop-and-go is still "driving". The weight of the hybrid doesn't hurt it as much due to the fact that some of the energy invested in accelerating the car is regained during regen, when weight actually (temporarily!) HELPS. Overall of course the weight hurts, but the very fact that energy is recaptured during braking gives hybrids a big advantage, FAR outweighing their increased mass.
Hybrids do get more optimistic epa ratings than non-hybrids. Still, their REAL-WORLD mileage is at least as good as the most fuel-efficient gasoline cars on the highway, and much better in-town and combined.
I haven't seen any evidence suggesting otherwise.
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You asked for an example of a similar gas car getting similar mileage. I gave it to you. Now you're calling it anecdotal.
No need for scientific testing since the engines are the same size and type and the cars are the same size and wind tunnel optimized, and they burn the same fuel. They require the same "energy" using the same "fuel" in the same sized engines using the same EFI systems at the same compression ratios. It'd be fun but there won't be any huge differences.
Why don't YOU show me one hybrid that gets better highway mileage than a simple diesel engine in a similar size engine in a similar car. If you really want cheap, efficient, simple, green, then you don't want a hybrid.
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What do you think "anecdotal" means?! You can't test ONE vehicle, use YOUR result for that vehicle, and then take reported results from OTHERS, doing entirely different driving profiles, and draw any REAL conclusions.
No need for scientific testing?! Now that really exposes your thought process. Pure conjecture.
I presume your Civic is an early-mid 90s 1.5 liter? It wouldn't surprise me if it did get as good better mileage than a Prius, but compact cars have gotten a LOT bigger and heavier since then. In any case, you have ONLY given ANECDOTAL evidence.
I don't have any real-world comparison of old, smaller, lighter-weight Civic vs. Prius, but in a real-world actual COMPARISON of the current Civic hybrid vs. its non-hybrid counterpart done by Road and Track, along with Ford Escape and Toyota Camry hybrid/non-hybrid counterparts (May 2006). SURELY a more valid comparison of hybrid vs. non-hybrid. Here's what they got for ACTUAL fuel economy under IDENTICAL driving conditions:
Overall (non-hybrid mpg/hybrid mpg)
Escape 19.9/29.9
Civic 32.8/40.7
Camry 26.3/37.3
Pacific Coast Hwy (non-hybrid mpg/hybrid mpg)
Escape 21.0/29.6
Civic 32.9/42.2
Camry 26.0/46.5
Rush hour traffic (non-hybrid mpg/hybrid mpg)
Escape 17.0/25.9
Civic 32/43
Camry 23.9/32.3
Mountaineering/high-speed freeway (non-hybrid mpg/hybrid mpg)
Escape 22.4/31.7
Civic 34.8/40.0
Camry 28.9/38.3
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LOL,
I was comparing apples to apples.
Same car size and engine size to same car size and engine size.
They compare right on.
Your list does not.
Duh!
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Your comparison isn't valid in the first place, because you "tested" only one car and assumed results from others' experiences (under almost CERTAINLY different driving conditions) were directly comparable. Also, your car is from an era when cars were smaller and lighter-weight in general. HARDLY apples-apples.
A hybrid "equivalent" to a gasoline car WILL HAVE a smaller engine, since a portion of its peak torque/power will be made by the electric motor. As I've said above, that is the only reason it should have a hwy mileage advantage. Still, that is not to say that the hybrid/non-hybrid pairs above are necessarily strictly equivalent...
The Escape pair are actually pretty close in performance, though. Hybrid 0-60 = 8.9 sec, non-hybrid = 8.5; hybrid 0-90 = 19.8 sec, non-hybrid = 20.5 (slower!). Pretty fricking close to equivalent. And the hybrid gets 50% better mileage overall, and 41% better highway mileage!
Throw away your preconceived notions and ponder THAT for a bit.
Post Edited (Jul 27, 7:48am)
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"Also, your car is from an era when cars were smaller and lighter-weight in general. HARDLY apples-apples."
Dude,
This thread is about a car from another era.
This thread is about using hybrid propulsion on that car.
Hybrid gas/electric propulsion will not be "better" than other engine systems in that car (and possibly will be worse in the old draggy body style and added weight).
No need to ponder platitudes or notions at all.
An old Justy engine by itself (without adding the weight of the electric hybrid driveline) will be more efficient on his Datsun. A hybrid electric on an otherwise stock Z car is dumb and will have zero advantage and adds complexity and weight and maintenance. Q.E.D.
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"QED", hah, you're killin' me!
I agree it's not the best idea in the world to try to make a hybrid out of a L-engined Z, but if it is done right and done well there will be mpg benefits around town. It no doubt could also be made more efficient with a Justy powertrain instead, but you could hybridize THAT and make further improvements around town, which is what the original poster actually proposed. I don't think it's the overall best idea in the world, but there WOULD be mileage benefits in town.
Our whole side argument has been about:
Dan: "hybrids will way outperform non-hybrids under most combined driving conditions"
Hybrid77:
"Not from what I've seen."
You went to lengths to try to demonstrate that hybrids will only get worse fuel efficiency, even suggesting that if similar cars, hybrid vs. non-hybrid, got the same efficiency on the highway, that the non-hybrid would SURELY get much better mileage in town and up-hill-over-dale than the hybrid. Totaly bassackwards! You have stuck to your preconceived notions and left objective reasoning and logic out of your arguments all along.
There's the hybrid vs. non-hybrid real-world data a few posts up. Do consider it.
In the case of a Justy-drivetrain Z vs. a Justy-drivetrain HYBRID Z, the hybrid (assuming it's reasonably well-engineered) will get FAR better mileage in town, and it'll be close on the highway. Combined usage, the hybrid should far exceed the non-hybrid's mileage.
QED indeed...
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You miss the obvious.
This is a junkyard effort with junkyard parts. You cannot create efficiency from a batch of non-optimized parts.
There are no regenerative brakes here.
There are no computer management systems.
There is no efficient battery here.
There is no efficient generator here.
There is no efficient electric motor here.
The ONLY thing that will happen is that the losses from the gas engine will be added to the losses from the electric motor/battery/charger to make a system that is actually LESS efficient than just choosing one or the other.
Scaling inefficiencies will not create efficiency.
Q.E.D.
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Applause!! Applause!!!
Gentlemen, Welcome to the table!
It's about time!
The optomist has no brakes, the pessimist has no motor.
I need a good parts car.........
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The problem is that the car is not only a raw electric car, it now has an on-board gasoline charging system. Let's ball park it and assume a 5% loss in the transfers for heat/friction/noise/resistance. You loose 5% in the transmission that is driving the generator, 5% in the generator itself, 5% in the batteries when charging.
Loosing 15% just in charging the batteries is a lot to try and make up. Starting with a draggy Datsun, rows of car batteries, and old drivelines is not the way to make up the difference!
The best bang-for-the-buck is to slap in a small diesel. It starts off at 20% more efficient than the gas engine to start with and then there are no losses in converting it's power to electrical energy and then storage.
You can't fool physics.