Engine oil AMSOIL or Motorcraft

Rotella T6 here. I was a long time Amsoil guy, but it's just too fracking expensive, especially with the amount of miles I drive a week.

ive always used motorcraft diesel oil. 10w30 in the winter and 15w40 in the summer.

I'm running Amsoil in my 06 GTi and loving it. No trouble with that I can tell, I check dipstick every fillup occasionally have to add some but not a quart, not even .25 of a quart. I've got almost 72k on the clock I did my last oil change around 67500 maybe a little more, and oil is still clean. Car sounds no louder or different from oil dealer had put in it.

i run 5-40 amsoil in my VRT as well

It's a little more pricey but extends change intervals and has worked for me. Keeps engine temps a bit cooler as well.

Now i am referring to amsoil, Delo 400, mobil one turbo deisel truck oil.

in my Diesels i use amsoil or chevrons delco synthetic for heavy duty diesel engines.

i change at the extended interval and use only 100% synthetic oil usually Amsoil. I plan on using the same in my TDI at the normal service interval unless vw makes a full syn diesel oil

The only oil I used in my Audi before Amsoil was Mobil 1, and this far surpasses it.

You will not get better, check the results yourself, I gained 9hp and 6 ft lbs of tourqe and increased my gas mileage per tank 35-50 miles.