Peterbilt has made changes to the Model 579 Epiq package that it says deliver an 8% fuel economy improvement for the 2018 model year.

For the 2018 model year, Peterbilt’s Model 579 Epiq is available with the Paccar MX-13 and MX-11 engines and is paired with the Fuller Advantage automated transmission, offering a wide range of horsepower and torque ratings. Fuel economy improvement resulting from the 2017 MX engines is up to 4% over the prior model year.

The new Paccar engines are also lighter by 50 pounds than previous options and offer extended service intervals, leading to more uptime and lower maintenance costs over the life of the vehicle, according to Peterbilt.

Predictive Cruise Control on the MX engine provides additional fuel economy improvements of up to 3%, according to Peterbilt. By optimizing the truck’s speed based on the terrain, Predictive Cruise Control allows the truck to operate in the most efficient manner for the situation.

The recently introduced Paccar 40,000-pound tandem drive axle is also standard with the Model 579 for linehaul applications. Its design optimizes power distribution and has fewer parts for reduced maintenance, greater reliability and a 150-pound weight savings. It features a through-shaft design that optimizes power flow in the forward rear axle for better efficiency and less oil churning losses, resulting in a 1% fuel economy improvement.

Peterbilt has also introduced new interior color options, automatic interior temperature control for the Model 579 and several other features to improve driver comfort, the company said.

“Peterbilt trucks and Paccar MX engines are optimized to deliver unprecedented levels of value,” said Kyle Quinn, Peterbilt general manager and Paccar senior vice president. “The newest generation of Paccar MX engines and powertrain technologies once again raises the bar for fuel efficiency, performance and reliability, resulting in the lowest cost of ownership in the industry.”