A&Q about 350Z
Q:
Does anyone know what the second rating on engine oil means? 10W-30 for example, 10W means it has thickness rating of 10 when tested at 0 degrees F I believe. The second part means it has the rating of 30 when tested at 212 degrees F if I remember correctly. But Im wondering, engine temperature can go way past 212 degrees, so how does testing and rating oil at 212 degrees mean anything?
A:
Engine water temp can get well past 212, but oil usually doesn't get much past 220 degrees, so wherever they rate the oil is more than sufficient.
A:
oh, ok. Thanks.