let's just say you live in...

[Brucelee]

For a quality synthetic, I would suggest that 7500 miles is tops, esp given the Boxes engine woes.

That is my opinion based on used oil analysis I have seen over the years.

Could you go longer? Sure. Question might be why?

IMHO.

PS-I change the oil in my Lexus every 5K and I live in SOCAL. I use Penzoil platinum synthetic.

[rzucchet]

7,500 miles is what I do.

[Topless]

Spirited driver, 5-6 autoX/track days, oil change every 7.5K or sooner if I notice any change in its color(dark oil bad).