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Credit: International Truck and Engine

International Truck and Engine introduced its new MaxxForce engines for severe service vehicles.

Two features that set the new DD15 apart are improved fuel economy and quick demand torque response. Torque response is the time it takes for an engine to go from minimum to maximum torque. In 1.5 seconds, you can use full torque from the DD15, compared with only 35% from the old Series 60. That engine took 4.4 seconds to reach maximum. Fuel economy is improved by 5% over comparable Series 60 engines.

Quiet, durable engine

International Truck and Engine Corp. launched its new MaxxForce engines at the show. The MaxxForce 11 (10.5 liters or 641 cu. in.) and MaxxForce 13 (12.4 liters or 757 cu. in.) engines will be available in International WorkStar severe service vehicles.

International developed its new engines in conjunction with M.A.N. of Germany to be a world-class engine for current and future emissions standards. They're constructed of compacted graphite iron (CG), which is 70% stronger and 40% stiffer than the compacted grey iron competitive engines use, with double the fatigue limit.

By taking advantage of CG's properties, International was able to engineer a quieter engine with excellent durability while saving more than 300 pounds compared to one of the leading 13 liter engines in service today. The MaxxForce weighs only 2244 pounds dry.

Power ranges for the 11-liter model are from 330 hp to 390 hp with torque of 1250 to 1400 lb-ft. The larger engine produces from 420 to 475 hp, with torque ratings from 1450 to 1700 lb-ft.

Peak torque is steady from 1000 to 1200 rpm, with more than 90% available through most of the rpm range. Although maximum power is at 1900 rpm and vocational engines are rated to 2100 rpm, the engine is most efficient at lower rpm.

I drove several variations on interstates and around a tight course similar to urban maneuvering. The engine is so quiet, it was difficult to shift by ear. Newer drivers will find it easier to adapt their driving style to the new engine's characteristics than older ones like me who may have to unlearn old habits.

The engine is very forgiving. Several times, I missed shifts and managed to grab a gear at around 700 rpm. In every case, the engine pulled slowly and steadily back into its torque range, getting me out of trouble without any shuddering or bucking. Of course, with an automated or an automatic transmission that won't be a problem.

Suspensions

No longer do drivers of concrete trucks have to suffer with back and seat-pounding rides. Both Watson & Chalin and Hendrickson displayed new severe duty air suspensions for ready-mix trucks. Air suspensions protect driver health as well as prolong equipment life.

W&C has an improved arm assembly for its TI-250L integrated trailer suspension for low-run heights. Hendrickson also improved roll stability with its PRIMAAX heavy-duty air suspension.

The new design also makes it easier to maintain and adjust torque.

— Paul Abelson is a former director of the Technology and Maintenance Council of the American Trucking Association and is currently on the Board of Truck Writers of North America. E-mailtruckwriter@anet.com.