Cat vs Powerstroke torque curves
I drew out what I expect the Powerstroke torque curve would look like relative to a Cat C11. I think it is very interesting how these curves reveal the different pulling characteristics of ...
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A truck/trailer on the Eisenhower pass at 8% grade and 30,000 lbs combined weight and 33" tall tires will need to put 4450 ftlbs of torque on the rear axle to maintain a speed of 40 mph. If the engine has enough power and the drivetrain can deliver more torque than that to the axle the truck will speed up. If the engine/drivetrain are not able to deliver the 4450 lbft of torque the unit will slow down. Slowing down will not change the torque requirement much......to maintain even a slow crawl will still require about 4200 lb ft of torque.
I'm going to say the 2016 Powestroke can put 85% of its torque to the rear axle. At 2800 rpm that equates to about 700 lbft and at 1800 rpm it works out to 731.
So to get to 4450 it needs a 6.36 gear reduction. If the truck is equipped with a 3.73 rear axle it would require a 1.70 gear reduction from the transmission. Unfortunately that gear is not there. The transmission would have to drop to second gear where it gets 2.32 gear reduction. Now it has more than enough torque but in second gear revved to 3000 rpm the Powerstroke can only turn the axle 347 rpm. The truck is only capable of 34 miles per hour. To turn the axle 347 rpm while delivering the required 4450 lbft of torque only requires 294 Hp at the rear axle so 345 flywheel Horsepower. That is about what the Cat C11 makes over a broad rpm range so without doing the math I'm pretty confident that the 335 Hp Cat would almost keep up to the 440 hp Powerstroke.
I'm going to say the 2016 Powestroke can put 85% of its torque to the rear axle. At 2800 rpm that equates to about 700 lbft and at 1800 rpm it works out to 731.
So to get to 4450 it needs a 6.36 gear reduction. If the truck is equipped with a 3.73 rear axle it would require a 1.70 gear reduction from the transmission. Unfortunately that gear is not there. The transmission would have to drop to second gear where it gets 2.32 gear reduction. Now it has more than enough torque but in second gear revved to 3000 rpm the Powerstroke can only turn the axle 347 rpm. The truck is only capable of 34 miles per hour. To turn the axle 347 rpm while delivering the required 4450 lbft of torque only requires 294 Hp at the rear axle so 345 flywheel Horsepower. That is about what the Cat C11 makes over a broad rpm range so without doing the math I'm pretty confident that the 335 Hp Cat would almost keep up to the 440 hp Powerstroke.
