LOUISVILLE, Ky. — Cummins will deliver improved fuel mileage through a combination of downspeeding and its new SmartTorque2 engine ratings, the company announced prior to the Mid-America Trucking Show.

SmartTorque2, available on the ISX15 in two new ratings (415 hp/1,450-1,650 lb.-ft. and 450 hp 1,550-1,750 lb.-ft.), “enables smarter acceleration and performance under a variety of operating conditions,” explained Jeff Jones, vice-president, North American engine business. SmartTorque offers an extra 200 lb.-ft. of torque in the top two gears for improved performance when cruising or pulling a grade.

A new vehicle acceleration management (VAM) feature controls the amount of power available to the driver when accelerating, providing smoother acceleration with less fuel consumption, Jones added.

The new Cummins engines have been designed to deliver peak torque at less than 1,000 rpm, to provide more efficient gearing.

“We’re recommending trucks with manual transmissions be geared for 65 mph at 1,270 rpm, which is 100 rpm lower than a year ago,” Jones said.

Dr. Steve Charlton, chief technical officer with Cummins’ engine business, said just three to four years ago, Cummins engines were cruising at 1,450-1,500 rpm, while today they can operate efficiently at 1,200-1,300 rpm.

Additional fuel savings can be had by using a 10W-30 low viscosity engine oil, Charlton added. And he said improvements have also been made to the emissions system, with more soot reduction occurring in the cylinder so there’s less particulate matter for the diesel particulate filter (DPF) to eliminate. Charlton said these changes have resulted in nearly 100% passive DPF regeneration.

Cummins also announced it is making significant headway in reducing fuel consumption through its SuperTruck partnership with Peterbilt. The two companies already have seen a 54% improvement in fuel economy, with a truck and engine combination that’s nearing 10 mpg. The SuperTruck features enhanced aerodynamics combined with improved engine technologies. A significant portion of the fuel savings are the result of a waste heat recovery system developed by Cummins, which converts exhaust heat into power that’s delivered to the crankshaft.

Jones said Cummins’ position with the OEMs has “never been better.” He indicated Cummins has seen its North American market share grow to more than 40% of the Class 8 and more than 50% of the mid-range markets last year.