Postby Alpha_2nr » December 2nd, 2006, 10:25 pm
On most cars, the manf'rs recommend an oil change of 5000 km or 3 months right? Most multigrade non synth oils do well with this sort of oil change interval . They have sufficient anti sludge and detergent properties. A daily driven B15 or Corolla is no where near the high performance category, and so don't need an oil which is intended for high temp/abuse applications.
Also keep in mind that Oils like Syntec or Mobil are NOT true synthetic oils. They are in fact generated from "Dino oil" just like GTX....however they are so highly processed, that by "law"/SAE regulations, they are classified as "synthetic".
Now a high performance engine...like a turbo one for instance...needs a higher quality oil..because rememeber that smae engine oil is lubraicting (and cooling) the turbo. That turbo get really hot...over 1200 deg F....so you need an oil which won't break down at those elevated temperatures and pressures. So in such a situation, you would need a true synth oil (which handles these situations better)....for a regular N/A car.....these conditions just don't exist. So a non-synth oil works fine.
The only difference between a synth oil and a non synth oil these days, is that the sy nth oil can withstand higher operating temperatures, and is more resistant to oxidation. Otherwise, most of the additives are pretty much identical. So IMO, save yourself some money.
