Bench racing and gearing

Updated Jul 13, 2015

Power Comparison DRW 3500 2Doing vehicle comparisons is at the very top of my “love-to-do” list.

Put three, four or five pickups hood-to-hood through a number of performance tests, such as towing, hill climbs, drag races, and fuel economy runs, and let the numbers speak for themselves. That’s fun.

But it’s rare that vehicle comparisons are really apples-to-apples, as those of us who do such comparisons know all too well.

Take the highest towing capacity diesels for example. If we were to compare the regular cab, long-bed duallies we’d quickly find out the one item that sets the three apart right away is they don’t have the same axle ratio.

The lowest axle ratio both GM and Ford offer in that particular package is 3.73s, while Rams have 4.10s.

A lower axle ratio means faster acceleration, all things being equal. Advantage, Ram.

So although Ford has a lower ratio first gear than Ram in their six-speed automatic, Ram still has the hole-shot advantage with the lowest final-drive ratio, not to mention a slight advantage in torque-to-weight ratio with the new 900 lbs.-ft. rating.

But after that, on paper anyway, it’s all Ford because its lower final gearing through the rest of the gears would make up for Ram’s fractional torque-to-weight advantage.

Where does GM fit in? It should have a highway mpg advantage over both Ford and Ram once all three trucks get into the double-overdrives. Again, all things being equal.

Of course, differences in engine rpm curves, tires, and aerodynamics play a role in all of this as well. Still, it does get one thinking about the importance of gearing, doesn’t it?

The point is, if you are looking at comparison tests, look at the performance numbers then take a close look at the all the vehicle specs. Pay particular attention to axle ratios and transmission gearing because they play as big a part in pickup performance as do raw horsepower and torque numbers.

It takes gearing to get that power to the ground.

And just for fun, when the new GM and Ford HDs come out, run the hp-to-weight and torque-to-weight ratio numbers to see who has the advantage and where.