Quote Originally Posted by Kaiser
And I agree with that, but at 20k miles, if your seals are even starting to go bad, then I think there's another problem in the mix somewhere. I was just pointing out that while I accept his experience as the right answer, it just seems out of place, wanted a really fantastic explanation for it. Not neccessarily from him, but just in general. I know a lot about synthetic oils, but I've still never figured out why Aerio took to running synthetic just fine (and was much happier because of it) while other people tell me horror stories about how a synthetic oil caused their engine to die. It's all just speculation for me, FI = Synthetic just because of the temperature range.
well i dont know for certian but from what i have seen and experienced is that once you do syn you really should stay with it. but also if the oil has the same weight and viscosity then there really isnt any difference as to why oil will get by the rings and burn. but for some reason there is. we have all seen that stupid infomercials on tv about syn oils and stuff when they heat it up spreading around the pan or block more. since syn seems to flow easier. i only see thats why when you go to syn at high mileage when the rings are worn more because of the conventional oil. when you switch its alot easier to get by the rings and burn. but if you use syn early and keep with it the rings would wear as much as if it was conventional oil. and if you go from syn to conventional at high mileage it will just wear out faster than the syn. so when you go back to syn you burn because they have been worn out faster. syn oil seems to be a thinner oil for the same wieght.

all i know is with a VQ if you used syn from early on stay with it. it will last forever. ive seen a VQ with 250k and all they used was syn the cylinder walls still had the crosshatch from honing. but whenever ive seen a car come in and they say they are burning oil. i ask what kind of oil have they been using and they say they have been using syn for the past 3-5 oil changes and thats when its been burning oil. so when they switch back to conventional they dont burn. so take it with a gain of salt this is what ive seen. its not gospel.