Motor Oil - Mineral Vs Semi Sync Vs Fully Sync

[CHB]

guys, what are the real scientific difference between these oil?
which oil suitable for force induction engine and which for NA?

[RyleyMA61]

a synthetic oil is less likely to change viscosity at higher temperatures than mineral based oils.

they are generally better for modern performance engines, but it depends on your driving too. i used a semi synth in my 7M and it was fine on the street, but at the track it sucked.

choose oil based on engine tolerances, if your engine is fresh and rebuilt. the engine may have been assembled at higher or lower spec tolerances and so different viscosity oils would be better suited than others

[abently]

Be aware that by synthetic oils we mean Ester based oils (Redline, Motul and a few others).

Having an accurate and large display oil pressure & temp gauge is a good investment to seeing which oil is doing its job better after 3000K's and also around the local track etc. Cheap insurance especially when its a $5000+ Engine you have in the car, that along with regular oil analysis.

[SuperDave]

There seems to be this misconception that synthetic oil is a wonder drug for your engine. The only way to tell if an oil is protecting as it should is via used oil analysis (UOA). Caltex make kits they supply to the trucking industry, minimum buy is like 10 though. Put oil in a little cup, send it off to the lab and then they send the results back to you with recommendations. Also helps if you send them a virgin oil sample.

[abently]

The only thing Synthetic does is give you greater mileage. All oils eventually break down by various means. Oil analysis is good for pin pointing future issues before it even becomes a real issue so in that regards it is money well spent.... and for the price of a real synthetic oil these days, you are usually better off using cheaper oil and changing it more often.

For track vehicles though, I do recommend you use a quality synthetic if you don't have oil pressure and temp gauge to keep an eye on things.

Synthetic is a wonder drug if you know how it works and how to get to best out if it, but in the hands of the average consumer this is usually never the case.

[JZA70R_92]

what would you recommend for a good cond 7MGE rebuilt approx 30,000km ago. right now iam using castrol GTX 3 for starters as it has'nt run in 5months. was gonna use castrol magnatec??? at the moment the top end is nosiy maybe due to sitting for awile...

[abently]

Depends, were the main and big end clearances set to factory specs or tighter ? How was the oil pump clearances (brand new or just checked) ? etc. You really need an oil pressure gauge to see if its at factory recommendations or not to then justify going to a thinner oil, which btw Magnatec isn't very much less then GTx3.