I put roughly 400-500 miles a week on my car and as you can guess it all highway could I change my oil less like instead of every 5,000 miles maybe 7,500??? I was just wondering because 5,000 seems like alot of miles and i didnt know how far I should push it and I rarely beat on my car what I mean is I rarely come close to red line.

Thanks,
Ryan

 

IIRC I did my g/f @ 1200 miles, then got a dealer comped one at 5k, then at around 8k changed to a synthetic, then again around 16k.

Her car now now has about 24k on it and I am contemplating changing it again too since its been in the car about 6 months now... We'll see though.

I am not so sure about waiting 25k or one year to do oil changes, I think that is a bit much. Has anyone gone 25k with the same filter and done a UOA running a full synthetic?

 

With primarily highway miles I'd be shocked if you couldn't comfortably get 7500 out of regular oil, and a lot more out of synthetic.

UOA is the only way to be 100% sure though.



Amsoil guarantees their oil for 25k/1 year change intervals. If you can show an engine failure due to it they buy you a new engine. In over 30 years in business it's never happened.

I don't think I'd do it on Mobil 1, but with a real group 5 synthetic like Amsoil I'd have no problem with it... (and that's what I did with my previous car, whose engine made a lot more power than the IS350 engine and wasn't built with as high a level of precision manufacturing as Lexus motors are).