Caterpillar received EPA certification for its C13 and C15 engines. The news follows an earlier certification for the C7 engine.

The Caterpillar C7, C13 and C15 engines use Cat's proprietary ACERT technology to meet the new, tougher EPA engine emissions standard for 2007. Cat says the technology allows them to adjust engine combustion under varying load conditions to reduce emissions and maintain engine performance.

Several truck manufacturers have already announced plans to offer the 2007 Cat engines in their models.