air filters? synthetic oil?

The air filter you mention sounds like the one that cleans the passenger compartment. As for when it needs to be changed, I would follow your manufacturer's recommendations. Typically in the past, I would change any air filter I couldn't see light through. Sometimes depending on where I drove, I would have air filters last longer than other times.

You can do what ever you want with oil. I've met people who drove

10,000 miles on conventional oil, but then it was because they didn't car they trashed their car. If you have money, then violating your car's warranty shouldn't be a problem, and if you don't follow your car makers maintance schedule you could be violating it.

I was taught, oil viscosity break down was at a much higher mileage than the typical oil change schedule, but that was only the laypersons concern. Oil has adtivives that protect the engine, first being a detergent, that keeps dirt suspension. This only last a few thousand miles, so you could be cruding out you engine. Add in there are pH buffers, and depending on you driving habits, you could be turning your oil acidic and eating out any protective oxiode layers and weating compenents even faster.

So long story short, follow your manufactures oil and air filter schedule ( or let your step dad provide a warranty in writing for your car. ;) j/k )

hth,

tom @

Mobil 1 synthetic has an extended performance blend that they claim is good for 15,000 miles. It is not the same as standard Mobil 1 synthetic.

You can read the stuff at the Mobil 1 web site and also see discussions at

for 10,000 miles in new cars if most of those miles are on the highway during trips long enough that the engine is fully warmed up. Short trips in cold weather is murder on engine oil. Older engines may require more frequent oil changes if previous owners were lax about maintenance. I've been using synthetic oil in my cars for over 15 years and am convinced the additional expense for the oil is repaid many times over.

Rather than ignore your car like most folks, it is important to routinely check your engine oil level, especially if you use an extended oil change interval.