Caterpillar’s C13 ACERT and C15 ACERT engines received the United States Environmental Protection Agency’s Tier 4 emissions certification. The engines are the latest to receive certification in the 130 to 560 kilowatt power category.

These engines, in addition to the previously announced certified C9.3 ACERT engine families, will power a number of Cat products such as mid-range track-type tractors, motor graders and hydraulic excavators.

It is projected that Caterpillar will accumulate nearly one million hours of testing on Tier 4 Interim engines and machines by the end of 2010.