Been using in my '07 Duramax for the last 10 years. I change the oil and filter every 5k miles. I use my pickup for towing fairly heavy loads on a gooseneck flatbed trailer and the engine seems to be doing what I ask. I used to use Chevron Delo 400 but at the time I switched, my neighbor was a long-haul driver making trips from WA to PA and said the Delvac was all they ever use in their semi truck.

So many motorcyclists use Shell Diesel oil, Mobil makes excellent products so I put this in my VStar for less $.. So far so good.

Best oil I've ever used in any tractor! Literally cleans the engine and you can go more miles in between changing oil than with other brands. All my tractors are diesel, would highly recommend!

Great product except the shipping

Motorhome uses 4 1/2 gallons so this saves me a pile of money on okl changes.

Best price around, use Mobil one in all my vehicles

Good oil, Used it for years.

For my diesel truck I like this oil because it has the Zinc required for the engine.

Great oil for my motorhome

Great price on sale. Works as good as any other product.