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2021, Emissions, Gear Ratio -

Gearing Canadian Kenworth & Differences in Detroit and Cummins Aftertreatment Systems

Gearing Canadian Kenworth & Differences in Detroit and Cummins Aftertreatment Systems

What were they thinking, maybe the problem is they do not think? A client of ours is purchasing a new W900-L or W990 in the Toronto Canada area, the truck will be powered with an X-15 Cummins and the 18-speed transmission, which has a final drive of .73 thus making it a double overdrive transmission. The dealer has a 500 horsepower, 1750 torque at 950 RPM, however the rear gears are 3:70 with low pro 22.5 tires. Really? Are you kidding me? This spec dates back 30 years ago. With a peak torque at 950 RPM the best operating range...

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2021, Gear Ratio, kenworth -

Differential Gear Ratios

Differential Gear Ratios

Differential gear ratios; there is a lot of confusion in the trucking industry about what is the best gear ratio for pulling power, fuel mileage, and a good cruising speed.  This article will pertain to the over the road semi truck, NOT heavy haul, or vocational local trucking. To pick the right rear gears you must know the peak torque RPM of your engine, the ideal cruising RPM, and the speed you mostly drive on the interstates.  Today almost all transmissions are double overdrive which is a .73 final drive gear.  The standard 13 and 18 speed transmissions are all...

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