Running full synthetic in 400,000 mile cummins

[weapons of grass destruction]

Hi I have 1994 cummins turbo diesel.
And i found a good deal on amsoil.
And changed the oil in it.
What I am doing is changing just the filter every 6 months.
And adding 2 quarts.
But adding amsoil is way to expensive.
So I heard it is not good to run full synthetic in high mileage cars. I was going to start to add start adding rottela t full synthetic.
But it is not good to run full syn in high mileage cars.
But amsoil I heard is different than other full syns.
What do you guys think.
Any help would be great.

[South Florida Lawns]

That amsoil is supposed to be good stuff. Look up a guy named nosparkplugs, on here he runs the dual bypass filtration system on his cummins. I think he went 89,000 miles without an oil change. Some guys will send off samples of their oil to a lab and it will still be perfect.

Me I run rottela t full synthetic in my cummins change it every 6k. Chevron Delvac 15w40 is good also if you wanna run regular oil.

[mnglocker]

@ 400,000 miles, just keep doing what ever you were doing and don't eff with it.