LOUISVILLE, Ky.V Volvo Trucks North America officials introduced Intelligent Torque at the Mid-America Trucking Show in Louisville, Ky. recently.

I-Torque is a feature of the new Volvo D16 diesel engine. The Volvo D16, which was shown to the North American public for the first time at the show, has up to 625 hp and 2250 pound-feet of torque. Higher torque means more power at cruise RPM: for every additional 200 lb-ft of torque, the D16 will produce more than 50 hp more at 1400 RPM.

Big torque is most important at highway speeds. Drivers want reserves of power to carry them over hills without losing speed and downshifting. Many also want the flexibility that a powerful engine offers to haul high gross weights when necessary. On the other hand, too much power at low speeds can cause wheel spin and excessive tire wear, or even damage drivetrain components. I-Torque protects components from excessive torque at low speeds by limiting engine torque output in startup gears.

Volvos I-Torque technology controls the amount of engine torque delivered to the driveline in any gear. This also allows Volvo to specify an optimized rear axle and suspension combination. So it is possible to specify a lighter rear axle and suspension than would otherwise be required.

In technical terms, I-Torque works by matching torque levels to transmission gear ratios (the ratio of engine RPM to transmission output RPM), to reduce tire wear and to ensure that the drive axles torque limit is not exceeded. Torque is multiplied by a trucks gearing, with low gears multiplying torque more than high gears. I-Torque works on manual or automated transmissions with any number of gears.

I-Torque has either two or three torque levels, depending on the engines power rating; the 600 hp/2050 lb-ft and 625 hp/2250 lb-ft ratings have three torque levels. These levels are matched to transmission gear ratios of:

h greater than 5:1 (low-range or startup gears)
h between 2.6:1 and 5:1 (low- to mid-range)
h less than 2.6:1 (high-range and overdrive).

In operation, I-Torque senses which gear is engaged, through sensors on the transmission input shaft and output shaft to calculate the current gear ratio. Depending on which range the gear ratio falls into, the electronic engine controller will use its programming to control the fuel supply to the engine, and thus its torque output.

For more information visit www.volvotrucks.us.com