whats up for some reason my girls last oil change ended up with full synth oil in her car, a 2005 buick lesabre custom. its got the 3.8l v6. anyway to not change back i picked up some mobil 1 and threw it in there. i use it in my evo of course and am religious for 3k mile oil changes. you think i could cheat a little with the buick and go to 5k for mobil 1? what do you guys do? I know there are some bmw and other dealerships that go 7-10k miles before a change on synth. i figure im safe with 5 for the buick eh?

 

Depends on the oil rating like how many miles you engine can use it before it needs to be replaced

 

i guess i will have to find that out then.

 

For awhile, I was going every 5k, but I decided I was still wasting money (I put on a lot of miles.) I ended up changing to 10k intervals and changing the filter every 5k, using RP oil.

Consider that many manufacturers recommend 5-7k change intervals with conventional oil, a good quality synthetic will take you a lot longer. In theory, synthetic should last forever with good enough filtration.

 

yeah ill go 5 probably. if its 20 bux every time i change it for mobil 1 tahts not bad. she wont put on 5k too quick she just runs errands and goes around town. i know that kind of driving breaks down oil quicker than highway driving, so ill be fine with 5 im sure. thanks

 

id say 5k miles, better safe then sorry