Originally Posted By: OVERKILL
Originally Posted By: homeyclaus
Originally Posted By: Leonardo629
Yes, Pennzoil 0W40 doesn't have LL-01 cert, 5W40 Euro does, but it's not as readily available.
Pennzoil 5W40 Euro don't even come in 5qt jugs on walmart.com nor amazon.com.
Castrol is of course the best alternative if you are keen on the LL-01 cert, but I just prefer the latest GTL formula.
forget about LL-01 for a sec, I still can't believe BMW really is prescribing 0W20 in the new 3.0L B58 engines pushing 320hp/330ft-lb.
And a Toyota Tundra 5.7L is 385hp, and specs vanilla API 0W20, even for towing, with a large number of trouble-free, high-mileage engines out there. Viscosity has less and less to do with film shear strength and the ability to carry heat, and as this trend continues thinner oils "might" provide cold start and other flow benefits.
It isn't the total power figure, but rather density that has historically led to the spec of heavier oil. In the two examples cited, the BMW is 106.7HP/L, whilst the Toyota is 67.5HP/L, significantly less.
Thinking of perhaps a more fitting example, Ford has recently upped the viscosity requirement for their power-dense force induction engines, which now spec 5w-30. If we specifically look at the Mustang:
The 5.0L makes 435HP, making it 87HP/L - specs 5w-20
The 3.7L makes 300HP, making it 81HP/L - specs 5w-20
The 2.3L makes 310HP, making it 135HP/L - specs 5w-30
The 5.2L makes 526HP, making it 101HP/L - specs 5w-50
As you can see, the higher power density engines spec heavier oil with the track-oriented GT350's 5.2L following the tradition of spec'ing Ford's 5w-50, which was the case for the Track Pack Mustang GT, Ford GT, GT500 and BOSS 302.
I understand.
Duty cycle is another consideration - one of those engines really tow. I had a Focus ST with its 250 hp 2.0L. But towing generates a high, constant load for long periods. Things get hot, but it's quite different from track use. What's the Ford 5.0 Coyote spec in the F150?
It's not as simple as bhp/L. It's possible other clearances are different requiring a different viscosity. I doubt that at operating temperature it matters much in anything other than edge cases, so run what makes you feel best.