Your DPU Questions!

I've looked online and can't seem to find what the zinc levels are in the Shell Rotella T6 5W-40 Full Synthetic Engine Oil; any info will be appreciated.

  • Zinc is an important component in Zinc dialkyldithiophosphate (ZDDP) which forms a sacrificial anti-wear film in an engine to help protect internal components such as a camshaft. Most Shell Rotella engine oils, including T6 5W-40 Full Synthetic Heavy Duty Diesel Engine Oil, contain approximately 1200 ppm of zinc which will benefit older and high-performance engines.
  • Shell Rotella T6 5W-40 Full Synthetic Heavy Duty Engine Oil with Triple Protection Plus technology delivers all the protection you've come to expect from Shell Rotella and then some as it not only meets but exceeds API CK-4 performance standards. Through the use of Shell's most advanced technology, Shell Rotella T6 5W-40 Full Synthetic Heavy Duty Engine Oil offers enhanced fuel economy performance1, protection in extreme operating temperatures and outstanding shear stability.
  • To purchase Shell Rotella T6 5W-40 Full Synthetic Heavy Duty Engine Oil, visit

How much of engine oil is made up of additives and how do they help an engine?

  • Shell Rotella engine oils are designed to meet or exceed the standard requirements as set forth by the API CK-4 engine oil specification and using a high-quality additive package is essential. The additive package represents approximately 20 percent of a gallon of oil with the balance being high-quality base oil. Additive packages play a crucial role in helping to keep an engine clean and protected from varnish and sludge, as well as provide wear protection and protection from heat and acids.
  • Additives are necessary in diesel engine oils to realize fuel economy savings, prevent deposits and maintain proper flow and viscosity in hot and cold temperatures. This is important with the increased use of 10W-30, 5W-40, 5W-30 viscosity grades, and even 0W-40 in extreme cold.

1 Compared to SAE 15W-40 heavy duty engine oils.