General Chat
Q:
is it worth the extra 20 or so cents a gallon to put 93 octane in my stock 280z or is it so old i could probably use leaded (if i could get some ;)
'78 280z -41,000 original(?) miles. a work in progress.....
A:
A better question would be to could you use 87 octane. My guess is you probably can, but the 70-83 tech section certainly holds the answer if you search.
19[TT]91
My TT beauty is gone.
2[00]2 Honda 954RR
Suzuki 1200 S; sportscar eater
19[I4]94 Integra GSR Sedan
Long live the Z...
aka SAHTT
A:
stock? no.
when new, it required 91RON, which is very close to 87 pump octane.
A:
On a stock 280Z there is no need.
---
Justin T
72 240Z L28, 5-speed
77 280Z 5-speed (t-boned 8-25-04)
80 280ZX automatic(retired)
A:
they have lead mix, i use it in my jeep.
----------------------------------------------------
1981 n/a 280zx
1952 m38a1 jeep willy's
1971 fairlady 240z
95 300zx N/A
72 240z
A:
Premium =93 octane is a rip off for most cars.
If you want high performance, maybe.
For regular driving use 89, only if the car knocks or diesels (wants to keep running after ignition is off) do you need to go to higher octane.
Very high compression engines like my 455 GM big block do have to have higher octane.
Tune your car accordingly to what you do use.
The car can get by on Regular - my 83 Turbo uses 87 oct. but #1 Son claims this is hurting the engine. I don't see it but the experts can enlighten me on that.
Neither the experts or #1 Son are paying for my gas, so I will need a lot of convencing on not using Regular in the Z's.
Ed and Jeanne's
ZXelda 1981 280 ZXT: ZXena 1990 300 ZX
1941 Buick Special Sedanette (Betty)
1956 Dodge Royal (Dorothy)
1971 Buick Riviera (Rita)
1975 Ford F-150 Stepside (Fiona)
1992 Firebird (Frieda)
A:
if my car is running a 10.69:1 C/R i should use premium right?
----------------------------------------------------
1981 n/a 280zx
1952 m38a1 jeep willy's
1971 fairlady 240z
95 300zx N/A
72 240z
A:
if my car is running a 10.69:1 C/R i should use premium right?
id think so... itd probably ping really bad without it... but i could be wrong.
77Z- (mfg. 7/77)
"Arm-chair Autox'er"
A:
(The car can get by on Regular - my 83 Turbo uses 87 oct. but #1 Son claims this is hurting the engine. I don't see it but the experts can enlighten me on that.)
got the same vehicle, 87 oct. is like coffee in the morning for these models LOL
(Neither the experts or #1 Son are paying for my gas, so I will need a lot of convencing on not using Regular in the Z's.) LOL
Have you shared the left lane today?
A:
Yea if you have above like 9:1 I'd go high octane rating. My 97 Eclipse had 10.3:1 and I still used 87, because it didn't even register to me, and it ran just fine. But my 91 turbo has 8.5:1, and I ONLY run premium in it.
A:
"For regular driving use 89, only if the car knocks or diesels (wants to keep running after ignition is off) do you need to go to higher octane."
NEVER BUY MID GRADE GASOLINE!
IN EVERY CASE, YOU ARE BETTER BUYING HALF AND HALF REGULAR AND PREMIUM AND LETTING IT MIX IN YOUR TANK!
You will end up with HIGHER octane, at LOWER COST than if you buy the mix from the pump. I have explained that OVER AND OVER and people STILL buy MidGrade, and advocate it. It is a RIP OFF. If you ping, start adding 1 gallon of Premium to 9 gallons of Regular and see if it stops. Using this formula, you will creep up on EXACTLY the octane requirement you require, without spending a bunch of money, DEFINATELY at a cost lower than Mid-Grade.
The stuff you get from the pump is MIXED in the pump. NOBODY refines midgrade, it's ALL mix-at-the-pump.
Don't be fooled by slick marketing. Mix yourself and SAVE!
People Are Idiots, Just look around here and you will see!
Tony D: "Knowledgeable but Caustic"... rationull
My brother from another mother calls himself "Willie D"
A:
"The stuff you get from the pump is MIXED in the pump. NOBODY refines midgrade, it's ALL mix-at-the-pump."
i did not know this. thanks tony.
A:
Do you think companys refine only 2 types of fuel and mix for all other fuels like race fuel on down??
SO maybe only 120 octane and 87 octane is actually produced and 89, 91, 93, 94, 100, 101, 103, 110, 120 octane fuels are made from those two???
Jason:
'77 280zT coupe: 8.8:1, flat tops, .030 over, Msd-6al, 60mm tb, cold air, 2.5" exhaust and DP, no cat, GReddy type RS BOV, medium intercooler
A:
racung fuel 95+ octane is made by speacial company's and you have to buy from them or someone who sells it.
----------------------------------------------------
1981 n/a 280zx
1952 m38a1 jeep willy's
1971 fairlady 240z
95 300zx N/A
72 240z
A:
For a 78 you shouldn't need lead either. It should have hardened seats in it. 78 was after the change in fuel, so it should be good to go. Just use regular and you will be fine. There will be no decrease in performance or mileage. Only high compression engines NEED high octance fuel. My 69 Chevy truck that had an 11:1 compression 327 NEEDED premium gas. It would run on like crazy on anything else. That really sucked as a daily driver with the whoppping 8 MPG I got. Good thing gas was cheap then (less than $1/gallon).
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:
I can only use premium in my NA, if I run anything else it'll run like crap for weeks until the fuel is out of the system entirely. Previous owner told me he was almost out of fuel once and the gas station only had regular and he had no choice but to use it. Ran like absolute crap until a few tanks of premium was run thru it again. I dont know if it has anything to do with my car being the Aus/Jap version but Premium is all I can use.
85' 300ZX NA
86' 300ZX Turbo
88' 300ZX Turbo
89' 300ZX Turbo
300ZX Turbo Project
A:
"experts ... to convince me..."
This is what I love about Zcar - people like Tony D. who have learned the hard way (by real experience i.e. racing and building your own) and are willing to give an invaluable education.
Thank you Tony - with your records and experience I will take your advise.
Ed and Jeanne's
ZXelda 1981 280 ZXT: ZXena 1990 300 ZX
1941 Buick Special Sedanette (Betty)
1956 Dodge Royal (Dorothy)
1971 Buick Riviera (Rita)
1975 Ford F-150 Stepside (Fiona)
1992 Firebird (Frieda)
A:
Take free advice for what it is worth; you can't apply Tony's logic to any new engine that can back off the timing with lower octane gas automatically. You may be carboning your engine, and at the same time the engine will not ping on lower octane. Therefore, you can't find the right octane just by trying to find ping, and you may think 87 octane is OK, but long term it will ruin your engine. Case in point is the BMW series of engines, all of which will run fine on 87 (and some on 85 octane), but you would be an idiot to do so longterm.
A:
Race gas formulations actually can be compounded differently for different classes. Racing fuel is the ONLY place you will buyu gasoline that is actually produced WITH TH SOLE INTENTION of being used in CARBURETTORS nowadays here in North America.
ALL fuel refined for commercial distribution is compounded for use with EFI. That is why guys are having drivability problems with SU's adjusted for proper mixture, and then have to fatten them up so much...
People Are Idiots, Just look around here and you will see!
Tony D: "Knowledgeable but Caustic"... rationull
My brother from another mother calls himself "Willie D"
A:
Yea, the DOHC cars with awesome computers retard their own timing to deal with th elower octane, but you get the correct performance out of it using the high octane. Tony was talking about an old car, such as our Z cars that are mostly SOHC and can't adjust their own timing, that's where he was coming from.
A:
"Take free advice for what it is worth; you can't apply Tony's logic to any new engine that can back off the timing with lower octane gas automatically. You may be carboning your engine, and at the same time the engine will not ping on lower octane. Therefore, you can't find the right octane just by trying to find ping, and you may think 87 octane is OK, but long term it will ruin your engine. Case in point is the BMW series of engines, all of which will run fine on 87 (and some on 85 octane), but you would be an idiot to do so longterm."
1) Well, we AREN'T talking about a newer car, ARE WE?
2)CARBONING and engine is done through EXCESSIVE FUELING, not through inadequate Octane!
3)You WILL NOT RUIN YOUR ENGINE, you will only suffer decreased horsepower output---if there is no PING, there is no DAMAGE!
4)BMW? What forum is this again? Z-Cars, and not a Z3 or Z8, so what significance does this have again?
ABSOLUTELY NO DAMAGE WILL OCCUR ON A MODERN VEHICLE THAT HAS SOPHISTICATED KNOCK SENSING CAPABILITIES AND THAT CAN ADAPT TIMING ON THE FLY TO THE OCTANE BEING USED.
The ONLY engines that are damaged by low octane gasoline in them are those that CAN NOT alter their timing!
I agree, free advice is what it's worth, and z32d00d is worth EVERY PENNY!
Not only is the post factually innacurate, it's downright MISLEADING! Better if nothing was posted at all, it has only added to the pile of bullsh*t on the internet that is innuendo, myth, and fallacy posted by someone who doesn't have a CLUE about what he's talking about, nor the SUBJET AT HAND!
People Are Idiots, Just look around here and you will see!
Tony D: "Knowledgeable but Caustic"... rationull
My brother from another mother calls himself "Willie D"
A:
To complete the example above....
if you look at the marketing position of the midgrade gasolines, you will see they are normally 10cents higher in price than regular, and high test is 10 cents more than that...
So for argument, say you have 91 octane, 89, and 87 available (California gas, let's not get into Michigan Sunoco with the spread of 94 Premium to 84 Sub-Regular!)
If pricing was 90, 100, and 110 each, pre gallon regular to mid grade let's see what you get:
Five gallons of 87 and five gallons of 91 would give you ten gallons of 89 octane for a cost of $10----same as if you bought Mid Grade from the pump.
So no harm, no foul. Buy mid grade from the pump in that case.
BUT, if you have an area where 92 is the premium, then you end up getting 89.5 octane from the same mix. You only really need 4.5 gallons or so to make that same 89 octane mix.
And if you try it with 94 octane, figuring the same pricing structure, the savings are even more!
And even in the "best case" scenario, by running a simple ratio, you can figure the gallons mix for 88 octane, you can see that if the car gets by with 88 octane, you can mix that for cheaper than mid-grade, too!
The dispensers inside the pump are simple ratio pumps, and mixing valves with ultrasonic flowmeters. They are very accurate, and can mix in a ratio wherever they are set to do so. The small margin on the midgrade the station gets is referred to as "Liquid Profit" because there is absolutely NO COST involved with the storing or delivery of the product. After the pumps are paid for, the investment is done!
Pay attention to the pricing structure, and the octanes available, my example is a "best case" where buying the gas from the pump is the same cost---I HAVE NOT SEEN THIS YET! Mid Grade is usually a penny more per gallon than what it should cost with a 50/50 mix of 91 and 87.
Someone said they need to sell a car for money in a pinch. I can say because he's not paying attention to details like this is the reason why he's in that frame of mind! Save where you can---it's only going out the tailpipe, best you keep your money in your pocket as long as possible, even if it is a few pennies. I use well over 1000 gallons of gas a year. A penney a gallon is a lunch or a movie rental that is "free" as a result!
People Are Idiots, Just look around here and you will see!
Tony D: "Knowledgeable but Caustic"... rationull
My brother from another mother calls himself "Willie D"
A:
To add to what Tony said:
A brand new car can adjust properly to run on any pump octane grade. The ECU will adjust valve and ignition timing to allow a "91 recommended" car to run with 87. The ECU will turn down a bit of power but it will not hurt the engine. It's like the engine is running on a secondary "low octane" mode. Even with a turbocharged engine with 10:1 compression, you can run the engine lean until it runs out of gas. I doubt anything horrible would even happen. Everything is factored into the ECU program.
Even old 240Zs don't have engines that are NOT very precisely tuned. The L24 with stock SU's have enough leverage to be able to run on 87 octane without a problem--maybe except for a bit of dieseling on hot days. These things are all figured into the engine by the manufacturer because dumb owners will not always follow the instruction manual. Otherwise, all cars will have engines as precisely tuned as Ferrari units. We'll all be changing oil from our dry sumps and adjusting our valves every 10k miles. Practicality is part of every well engineered car.
1971 240Z
"Fear is exciting for me." -Ayrton Senna
Post Edited (Dec 27, 1:15am)
A:
From what I know running your tank until it's bone dry isn't too good for your fuel pump because of all the gunk sitting in the bottom of the tank gets run thru it. I suspect this would be even more vital for older cars...
85' 300ZX NA
86' 300ZX Turbo
88' 300ZX Turbo
89' 300ZX Turbo
300ZX Turbo Project