amirite

I hear the recommended is 10W-30 (this probably isn't the same for all regions of the world) but I'm curious if anyone has been using Mobil 1 0W-40... Would this be harmful/better/worse/no different than running the recommended 10W-30 grade?

INDYMAC

It will work fine. It's a high quality synthetic that has many specifications for high performance vehicles (European). It tends to shear quickly (lower viscosity), so you probably won't notice too much difference in performance. The engine should operate very smoothly, including VTEC engagement.

dparm

Why do you want to run 0w40?

amirite

I'm just wondering because my father used to run 0W-40 in his BMW, and people had told him it was "the" oil to use since it was the best.

I've been doing quite a bit of reading on motor oils and now I see that he would realize barely any benefit from this. Are most of you using a fully synthetic 10W-30?

Swiftoy

Why not 5/40 amsoil. owners manual states 5/40 is okay to use. 0/40 should be fine

Swiftoy

amirite

I just emailed the guy that wrote up the articles on carbibles.com and he told me that it there's a chance it might not reach operating viscosity quickly enough, which would result in low oil pressure. There's a very small chance it would do any damage, but in my climate (VA) it would be pointless to use a 0W oil and he's probably right. Where was your car originally sold? I think what the manual recommends really might depend on the intended market's climate.

2007 Zx-10

These "0w-" oils are more of marketing gimmick than anything else imo. High grade 10w-30 synthetics, such as Mobil 1 EP or Amsoil, have excellent pour point and cold crank viscosity, so any advantage at start-up is going to be nil. "That's what Beemers use" means less than nothing. It would be interesting to compare shear of Amsoil 10w-30 and Mobil 1 0w-40 after 5k miles, my money is on Amsoil, I've been very impressed with their 20w-50 product in my turbo rotary (the ultimate torture test for any oil)

2007 Zx-10

I'll add that I'm running Valvoline Synpower 10w-30 right now in the S and I've seen very good UOAs.

amirite

I'm doing a shitload of reading on this subject and the more I read, the more it seems that very few people know what they're talking about so I'm getting pretty paranoid. Most of what I've read is consistent with what you said. When I buy an S2K I plan on using Mobil 1 10W-30.

Could you please explain why it's not good to use a fully synthetic oil before the ~10,000 mile mark on an S2K (or any other car for that matter)? I understand that it has to do with break-in, but what is it about that oil that helps the process? Does this mean that the oil shouldn't be replaced at all before that period or what?

2007 Zx-10

Synthetics lubricate so well that they delay the break-in process. I switched over at 4.5k. Then again, vettes come from the factory with Mobil 1 and they don't seem to suffer any ill effects (aside from the fact the LSx motors are known for relatively high metals content in the oil for a extended period). Complete break-in of a well built engine like the F22 can take as long as 15k