Oil

[Jools]

just found out mechanic has put 10w 40 motul fully synth instead of 5w40...is this ok?

 

[Sean197]

The difference is minimal, especially on a 'worn-in' engine. It's highly unlikely to do any damage per se, however bear in mind 10w40 is slightly thicker than 5w40 and it will take slightly longer to properly lubricate the engine on cold starts.
Therefore if it were my car I'd be telling him to put the correct viscosity oil in it.

 

[Jools]

Cheers for that Sean

 

[Pav]

The difference is minimal, especially on a 'worn-in' engine. It's highly unlikely to do any damage per se, however bear in mind 10w40 is slightly thicker than 5w40 and it will take slightly longer to properly lubricate the engine on cold starts.
Therefore if it were my car I'd be telling him to put the correct viscosity oil in it.

thanks...

 

[eurospec]

I'd put the proper stuff in. If you drive the car hard/on track a thinner oil cools the internals of the engine better than thicker stuff, plus offers better protection from cold starts. Having had various different track cars, I've always found the manufacturer specified viscosities to be pretty much spot on for oil temperature and pressure.