I almost at 60,000 miles/3 years without an oil change. I use a MotorGuard TP bypass filter. I change out my TP at about 1500-2000 mile intervals and add about a quart of makeup oil. I change out the full flow filter yearly. My oil analysis come back stellar.....essentially analytically clean. To change my TP and add the quart of makeup oil takes me all of 10 minutes. So when the Amsoil zealots say it's "labor intensive" take it with a grain of salt. And to really tick the Amsoil boys off......I'm running WallyWorld SuperTech 15w40 dino oil!!!!! I do use Amsoil in my diffs, tranny and transfer case however!!! My truck is getting really good mileage also!! Last tank averaged 21.6mpg hand calculated......all suburban type driving with a little country driving.

 

I get my oil for free ( work ) so i change it every 5000 but when this oil well dries out , im gonna get a bypass setup.

 

BEEN USING AMSOIL W/BYPASS FILTER FOR 61000 mi CHANGE OIL FILTER @25000 BYPASS FILTER &OIL FILTER @ 50000 JUST REPLENTISH FOR FILTERS . OIL TESTS EVERY 20000 mi ALWAYS BEEN PERFECT BEST PRODUCT I HAVE EVER USED AMSOIL IN ALL MY CARS AND TRUCKS

 

i ran coventional oil in my 04 powerstroke for a year, changinging it every 5,000. every time the magnet on the plug and metal powder on it. switch over to amsoil, changed oil every 20 to 25000 miles and the filter every 5000,and the plug comes out clean. when the head gaskets got changed the garage put conventional back in and the plug came out with powder on it again after only 3000 miles. my truck has 181450 miles on it. i'm a firm believer in amsoil or any snythetic oil.