A. The most important factor for getting the longest life possible from your engine is to perform the proper maintenance per the engine manufacturer's recommendations in the owner's manual. Special care should be taken when changing the air cleaner to be sure not to allow loose dirt from the housing to enter the air system. Do not blow out or beat the filtration element to remove dirt as this action will sometimes tear the filtration paper and provide an opening which would allow dirt to enter the engine. Also, check for loose air system clamps and be sure nothing is rubbing against the intake piping that might wear through and create a leak allowing dirt to enter the engine.

A. Engine life is defined as miles until the first in-frame overhaul is required.

B50 life (in miles) means that half (50%) of the engines built will need to have an in-frame overhaul completed by this mileage. Cummins ISX engines have a B50 life of greater than 1 million miles, for instance, so 50% will need an in-frame overhaul before 1 million miles, and 50% will need an in-frame overhaul after 1 million miles.

The term "B XX" was actually created by the ball bearing industry during World War Two to classify how long their ball bearings would run. The term has been carried over to the current heavy-duty diesel engine business.