Efficiency Is More Than Fuel Economy.

The X15 Efficiency Series has the best fuel economy of any engine in its class, bar none. But there’s more to efficiency than miles per gallon. It’s having the best uptime in the industry, with the longest maintenance intervals so you can rack up more revenue miles every year. It’s having over-the-air connectivity so you don’t have to take time to visit a dealer for calibration updates. It’s real-time diagnostics that accelerate service accuracy and speed. It’s having the biggest, most capable parts and service network in the industry, so you can get rapid assistance no matter where your loads take you.