Originally Posted by vwhobo
Those in the know aren't stupid enough to go 15k miles between oil changes... EVER. No matter how good an oil is, it becomes contaminated at the same rate, therefore regular oil changes are still a requirement.
I work in a Pennzoil quick lube, and I have to agree.
Always change it regularly, but since vw didn’t give a time frame I will. Regular oil especially Pennzoil and Quaker state always do every 3k miles, not sure if it's still true for both oils at this point but both were paraffin based which means the base product was bird oils (even if it's not still true, better safe then sorry I always say), now its good at lubing but it brakes down and becomes wax in side the engine if not changed regularly.
As for the other brands of regular oil, probably should be changed every 3k as well.
For semi syn feel free to stretch that to 3500, I use valvoline durablend in my breeze and it’s working very well, but I still only do 3k miles with it.
Now for the full syn stuff, I’ve talked to a lot of customers, fellow Fiero enthusiasts, and we all agree (you may not but those I’ve talked to do) almost all full syn are basically the same, and you should be able to push the oil change to ever 5k miles. I use Mobile 1 in the Fiero because its the name I know and trust, if you trust someone else keep trusting them I’ve heard nothing bad to make me say other wise.
As a little aside the Fiero has been running full syn nearly its whole life when the engine was rebuilt 40k miles ago and since then its seen the track several times, and been on the street several times. When I did its last compression test it was 130/150 across all 8, so even with all that hard driving not seeing any side effects yet.