Originally Posted by panic
"20W" is not 20 weight...

But that's how it appears in the manual

You always want to run the lightest weight oil you can because the oil does not reach its listed viscosity when cold. 30 weight (or ever 30W) oil much more viscous 'cold' then when at operating temp... and the few minutes its takes to get to operating temp is when all the wear takes place.

You will see lower gauge pressure with the lower viscosity oil on worn engines and using 30 weight or even 40 weight oil is not a fix, just a crutch to make the oil gauge 'look right'.

So it is 'wrong' to use 30 weight oil? No. Given the choice 20W or even straight 20 weight oil is preferred.

Last edited by pfarber; 07/01/2014 2:01 AM.