Navistar Launches Fuel-Saving ProStar ES

LISLE, Ill. – Claiming significant fuel savings, Navistar has formally introduced the International ProStar ES model first shown last month at the American Trucking Associations conference.

‘ES’ denotes ‘efficiency specification’, a package that combines the best aerodynamic features in the company’s bag of tricks plus a choice of drivetrains that use engine downspeeding and transmission automation to good effect combined with the most efficient rear axles available. The spec’ing expertise of International’s Performance Engineering Team is part of the deal, as is Navistar’s proprietary OnCommand Connection remote diagnostics system.

Navistar claims the new model is 11 percent more fuel efficient than a 2010 ProStar with a MaxxForce 13 engine and a manual 10-speed gearbox.

The ProStar ES was developed to have the lowest wind-averaged drag coefficient in the industry, the company claims, with particular attention paid to supremacy in crosswinds. Aerodynamic testing was done in the full-scale wind tunnel at NASA’s Ames Research Facility. The package can include the Eaton/Cummins SmartAdvantage powertrain which pairs the Cummins ISX15 engine with the Eaton Fuller Advantage automated manual transmission. Another option is to spec that transmission with Navistar’s own MaxxForce 13-liter engine. Both are matched with efficient 6×4 rear axles from Dana or Meritor, or a 6×2 from the latter company.

Navistar says fuel savings ranging from 3 to 6 percent are possible with the SmartAdvantage powertrain, largely because of its downspeeding strategy that allows either engine to run at 150-300 fewer rpm at cruising speed vs. previous offerings.

The ProStar ES package also includes a three year subscription to OnCommand Connection, Navistar’s predictive diagnostic system which includes a portal that monitors vehicle performance in real-time to ensure maximum operating efficiency.

Navistar says its experienced Performance Engineering Team, who developed the ProStar ES, can further optimize customer-specific specifications based on application and duty cycle. Navistar will begin taking orders for the ProStar ES as of December 15.

Rolf Lockwood is editor emeritus of Today's Trucking and a regular contributor to

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