Looking on Amsoils site it recommends changing the oil every 7500 miles if you use their synth oil and filter. Anybody else that tows a decent amount gone to this service interval using Amsoils products? It would cost me roughly the same amount of money if I went with Amsoil every 7.5k vs Motorcraft products ever 3k. It definitely would be nice not to have to change the oil as often.

 

Does it list any other interval for severe use?

 

7.5M on Amzoil should be no problem whatsoever unless you do a LOT of short-tripping or live in an icy climate. The maybe 5M to be conservative.

 

The only Amsoil with a 7,500 mile interval is the XL series, and that's not the one you want. Nothing wrong with that one, it's a great oil, but the true full synthetic is any of the others. Intervals are 25,000 mile normal service and 17,000 severe service. Sent you a PM.