Originally Posted By: stchman
Originally Posted By: fenpark15
I have a 2012 F150 with a 5.0 V8. The manual and oil cap specify 5w20 for all conditions. However, I still own a case of 5w30 full synthetic from my old vehicle. Is it safe to use this up for the next 2 oil changes and then switch back to 5w20? Anything I should consider or worry about? Thanks in advance for considering my situation.
It will probably be OK, but considering what new vehicles cost, why take a chance? I would put in the recommended viscosity.
Of course it'll be ok. Going a grade thicker isn't going to hurt anything.
Engines are built to work with a range of lubricants,because there is no such thing as a one size fits all.
Do they sell that engine in Australia,or Europe. Have a look at what they specific over there.
So by all means use it fenpark. And don't pay any attention to anyone spouting the nonsense that you absolutely NEED to use a 20 or they won't work properly.
It's total nonsense. All those same systems work just fine when a 20 grade is used during the winter,when the 20 grade is hundreds of times thicker than at operating temp. Those systems work as designed when cold.
How is it even remotely possible for an oil that's a grade thicker Than the NA spec when the only difference between the 2 grades is the hot spec.
When cold(below freezing) both grades share the 5 which means they behave similarily when chilled.
So to conclude and sum up;
There is absolutely no reason not to use it if you've got it laying around. It's nonsensical to believe harm will come.
Not by going thicker by a single grade.
Thinner may not be smart but thicker,gimme a break.