Whats the right time to change Mobile 1 oil? Right now I am changing it every 5k miles, but mobile 1 has some new oil that can be changed every 15k. Is that safe? What all do you guys do for oil changes, they can become pretty expensive.

 

sounds about right.. I did mine at 6.5k and it was dirty.

 

I've gone over 5k once and the oil wasn't in the greatest shape (it was the 15k mobil one oil). My thought is that 5k is the max. Plus,it seems that synthetic oil burns off a little more between changes.

 

How much oil is our Z's burning between changes? I've read a quart +. Is this right? I'm a new owner.