High Total Base Numbers are important to control deposits in four-stroke cycle diesel engines and to neutralize the effects of high sulphur fuel in all diesel engines. For two-stroke cycle engines, Detroit Diesel recommends lubricants with a sulfated ash content of 1.0% or less and TBN’s between 6 and 10 for engines operating on less than 0.5% sulphur fuel. Starting in 1994, diesel fuel for U.S. highway vehicles was limited to 0.05% sulphur content maximum. The need for high Total Base Numbers for over-the-road Detroit Diesel Engines ceases to be a problem in the U.S.A., providing the customer is buying fuel meeting these specifications. Of course, off-highway diesel fuel may still have sulphur content much higher and that’s where real care must be exercised in the recommendation of the proper engine oil.

It should be noted, PRO-SPEC^® D. D. MOTOR OIL is formulated in such a way that it will keep the engine cleaner than low ash commercial engine oils. PRO-SPEC^® D. D. MOTOR OIL is better due to a combination of excellent detergents and dispersants, a superior oil additive package, and highly refined base oils. The base oils have been refined in such a way to make the oil accept these superior quality additives – – – and the overall result is a cleaner engine.