Another which oil thread

[IPAddis]

My step dad who has been building engines and cars for the past 20-30 years is adapamant that fully synth should not be used unless you can be sure the car has only had fully synth in it in the past....

Is this true?

No. Most older engines are run-in on mineral oil before being switched to fully synth.

 

[energy]

I'd use a good fully synthetic (Castrol Edge, Mobil 1 etc) on a turbo performance motor, semi synthetic is a stingy choice IMO

 

[ubersonic]

I'd use a good fully synthetic (Castrol Edge, Mobil 1 etc) on a turbo performance motor, semi synthetic is a stingy choice IMO

Castrol Edge doesn't come in the right viscosity and Mobil 1 fully synth is hard to get here in the right viscosity, it would be £71 delivered and I don't really want to spend that on something that will be poured away in 3000 miles, thats more than Toyota would charge to do the oil change inc their reccommended oil lol.

What do you guys think of "Gulf Competition 10w-40 racing engine oil" its fully synth

 

[Gaijin]

They all look semi synthetic, get some fully synthetic thats usually best.

What do Toyota recommend ?

Assuming its currently on semi-synth, aren't you not supposed to change from semi synth to full synth if the car has been running semi synth for a significant portion of the life of the car?