How often do you guys change your Mobil one oil?
Lets say, you do avergae driving 50/50 city/highway.
I plan to change it 6000-7000 miles. it should double the drain interval.

 

im willing to do it every time i service the car...think of it this way...if u service your car every 3,500 miles or so like i do, u're gonna b paying for the oil anyway in addition to the filter and removal, so for an extra few bucks, y not use Mobil 1 every time?? better to b cautious than risk the limits of the oil, right??

 

My driving is mostly highway, and I cahnge Mobile 1 and filter at 10,000 miles.

 

Nah, I consider "Servicing" and oil changes two different things.
I change oil strictly by miles and time.

 

This sounds fine!

yeah, synthetic oil should be used for at least 5000-6000 miles

 

every 7500 miles.

 

I do mine 4,500 miles(mobil1 trisyn), i usually go with mileage than months when i do my oil change...

 

If you are paying twice as much for synthetic oil, why not get twice as much from it. Synthetics are proven to be fine twice the normal drain interval.

 

every 7500 miles.