how often to replace it with filter?

every 15000 miles as they say?

I currently have amsoil that is good for 25000 miles and I just did 12000 miles up to now

 

well, the mobil1 is on sale at autozone with a $57 discount, so it's really half price of the amsoil and I can pick it up right away

I need 12 qt because F150 = 7 qt and I have a honda accord to do as well that needs 5 qt

 

With a supercharged motor and driving it hard I wouldn't keep it in more then 5000 miles.

 

I know its overkill but I still chamge my motorcraft oil and filter every 3000 miles ,just for insurance . Oil change is cheaper than a motor.

if and only if I didn;t run a supercharger I might think about going 5000

 

Widj:

With your supercharger, I wouldn't leave ANY oil in there longer than 5000 miles, not even 25000 mile Amsoil.

FYI, the Mobil 1 oil filter is internally the same as the K&N filter.

 

And the Mobil - 1 is API certified!

 

I just purchased the mobil1, so they say 15000 miles on the box but you guys recommend using it for just a third ie. 5000 miles?

why would a supercharger require a more regular oil change?

 

Read post #1.

Fuel dilution and contamination.

 

With all the variables having the oil tested gives you a guide line on how long you can use the oil, without that your best bet is to use the factory recomendations. We don't know what tempertures, load, environment (dirty, humid) your running the vehicle in. But if you get the oil tested you will get a baseline on oil performance and then can make a good judgement on how long between changes.