Originally Posted By: DoubleWasp
Originally Posted By: Gokhan
Originally Posted By: aquariuscsm
Haha same here. I just can't force myself to use a 0W oil in my car. Nissan says not to go below a 10W. I know 1996 was a long time ago,but I'm like you,0W oils seem like a no-no to me
Lol. That statement by Nissan is totally obsolete and irrelevant. It only applies to yesterday's conventional oils that sheared a lot.
It has been explained on BITOG many times that a synthetic 0W-x will perform no worse than a conventional 5W-x or 10W-x -- if not better. Therefore, there is no reason not to use a synthetic 0w30 or synthetic 5w30 when 10w30 is specified.
The only possible exception is 0W-20 in turbo applications. 0W-20 is exempt from some high-temperature-deposit tests of ILSAC/API that apply to turbo applications.
For some reason, our Jeep 4.0's don't seem to appreciate receiving less than a 10W. Not saying it applies to all, but used oil analysis have shown increased wear with 5W's.
Conventional 5w30 will shear (to near xW-20 weight) and perhaps run too thin if your engine likes thicker oil. There shouldn't be any shearing issue with a quality synthetic 5w30 or 0w30 if the OEM calls for 10w30 but not 5w30. If 10w30 but not 5w30 is specified, Mobil 1 0W-40 SN is an excellent choice and will protect against wear more than conventional 10w30. Conventional 10W-40 is OK, too. Toyota calls for 10w30 (but not 5w30) or thicker for my engine and Mobil 1 0W-40 SN seems to be performing better than any oil ever did. I seem to be getting better fuel economy with Mobil 1 0W-40 SN than with TGMO 0W-20 SN. TGMO 0W-20 SN was probably too thin for my engine and increased the friction and wear as a result.
