I had used a “blue” container of oil for my first service on my 2023 48hp tractor. The engine seemed noisier than the factory oil. After 20 hours, I switched to Mobil Delvac 15w40. I instantly could tell it ran smoother and a lot quieter. I like it so well, I bought 4 more gallons to have on hand for my next service.

I have used Mobil Delvac for many years in my trucks they both have run over a million miles before the rebuild.

Works perfectly in my 6.0 Powerstroke. Never had any problems. Always have excellent performance year round!

Many miles and hours on Mobil !!! Always done me good

Been using for 50+ years keeps my John Deere farm tractors running like new.

I prefer this oil for my recently purchased diesel truck. It's a 1996 F-350 turbo powerstroke and has 345,000 miles, so a long engine life oil is important to me. It holds 15 quarts so it's great, and makes sense, to buy it in the 5 gallon buckets. I will continue to use it and was also recommended by my son.

This is all we use in our diesel trucks. Works well and no issues with our engine. Since we only drive diesel trucks, we go through a lot of this oil.

Use in my semi for years. Prefer Mobil to be used in my heavy trucks as well as my personal cars. Mobil is cleaner oil and my semi use to leak using Rotella oil. When started to use Mobil Delvac I have no issues of leaking or nor have to add to oil between oil changes.

We have used Mobil Delvac for well over 40 years. We trust it in our heavy machinery and equipment. It is the only oil we use.

I worked for a Shell Distributor for 33 years and have always been partial to Shell T4 1540, however when Shell went to has to liquid technology customers started to have issue with oil pressure and consumption. When I left the oil company I switched to Mobil and notice my equipment carried better oil pressure and no consumption. There for I feel Mobil oil has better technology.