Hi,

Is it ok to mix fully synth with semi sythetic oil? The dealer used semi synth and I am topping up with fully synth, but someone told me that I shouldn't.

It isn't a scoob, or a turbo, so semi synth should be ok shouldn't it?

Chris

 

Hi Chris,
I've done quite a bit of reading up on this whole oils topic and I would be amazed if you were to have any problems mixing semi-synth with fully synth. The only probs I have heard about are when people have gone from long term mineral oil use (ie GTX) to fully synthetic, as the synth oil disloges all sorts of gunk in the engine and causes havoc.
If you really want to be sure, try emailing the technical department of the oil company in question.
Hope this helps

 

You should`nt have any probs as the basis for both types is the same. The avoid mixing oils thing dates back a "few" years when you had to avoid mixing castor based oils (eg Castrol "R" ) with mineral oils.
JohnD

 

Hi,

Cheers for that, just wanted to make sure.

Chris