Originally Posted By: sir1900
This topic has been beaten to death but in the interest of answering your one question:
Real world difference? Negligible. The difference will be the flow rate at cold startup and a few MPG. The claim is that in 0W vs 5W you will see the savings in fuel, but one must factor in the cost of the oil over time.
Not exactly sure of your location, in the US, the savings may make sense. In Canada, perhaps less so seeing the cost of synthetic is double that of conventional (regular price vs regular price)
Do stick with the 0W to maintain the warranty.
Originally Posted By: DragRace
Originally Posted By: sir1900
This topic has been beaten to death but in the interest of answering your one question:
Real world difference? Negligible.
AGREE!
No need for these kinds of topics to get spread out into 10 or more pages.This happens wayy too much on these boards lately.
Did every one answer it the way you guys did previously or was it ever mentioned that one reason for mandating 0W might be simple, smart assurance of a minimum quality oil being used over a maximum interval.
In this case, the worst 0W is typically of MUCH higher quality than worst 5W. How many no-name 0W oils have you guys seen?
Originally Posted By: The Critic
Originally Posted By: JOD
Originally Posted By: The Critic
Supposedly on some models, the ECU programming has taken 0w20 into account and therefore, the VVT is programmed to operate accordingly.
One of my buddies who is a shop foreman at a major dealership says that he has seen start-up issues when 0w20 is not used.
That's total nonsense, since 5W20 is often much thinner than 0W20 depending on ambient temps--and some 0W20's are thicker than some 5W20's at operating temperatures. Your buddy should stop spreading misinformation.
I'm personally skeptical, but this guy has never led me wrong...ever. He did say that he had one Gen III Prius in that had an issue with start-up rattle/noise, and it turned out that the last oil service had been done with 5w30 instead of 0w20; installing 0w20 cured the problem.
Was the oil filter replaced in each of these instances, as well?
Comparing 5w30 to 0W-20 isn't quite the same as 5W-20 to 0W-20.
Hydraulically operated systems can't be THAT sensitive to viscosity. It just doesn't make sense that oil wouldn't flow through and pressurize the applicable mechanism as soon as the solenoid energizes.