Quote:
Originally Posted by Gasoline Fumes
I posted this on your other thread, but I'll put it here too.
The 0w oils are Mobil 1 fuel economy oil and the 5w-30 is normal Mobil 1.
0w-20 @ 100°C = 8.7 cSt
0w-30 @ 100°C = 10.9 cSt
5w-30 @ 100°C = 11.0 cSt
0w-20 @ 40°C = 44.8 cSt
0w-30 @ 40°C = 62.9 cSt
5w-30 @ 40°C = 61.7 cSt
|
As you can see, the 40c rating is 104f and is still much thicker than it's 100c/212f viscosity. Install an oil temp gauge and find out what temp the oil gets up to. If it gets up to 100c/212f then a 30w will work well. If it only gets to 190f then a 20w 'operational viscosity' is slightly thicker than the 30w at 212f.
My cars oil temps run 185f most of the time and only got to 200f once.
This means my 20w oil has an operational viscosity of a low to mid 30w.
With the lower oil temps, you can run a thinner weight and take advantage of a thinner oil at startup, which flows faster and reduces drag.
Now, I don't know how much mpg you 'might' gain, and I say this because I normally run 5w20, but I did run 10w30 (also approved in the manual) for one oil change interval and got the best mpg with it than with any other oil.
Too much BS out there and it's good to have a place where REAL people can share experiences.