dsherman26
Member
Not making anything up at all, and has nothing to do with shifting down a gear. If you're going up a hill, towing a load, it requires force between the wheels and the road to move. Where does that force come from? Torque applied through the driveshaft through the differential gears. A 3.92 rear axle ratio reduces the rotational speed of the driveshaft by a factor of 3.92, and torque applied from the driveshaft increases by a factor of 3.92 to drive the wheels. Yes, physics can back me up on that. So, if you have a 3.21 rear axle, same concept, except now, it's going to require additional torque from the driveshaft and the transmission to get the same amount of torque at wheels. Sure, you can downshift a gear so the engine is better matched to keep things moving, but it doesn't change the fact that if you're towing a full load up a hill at highway speeds, the lower 3.21 ratio will need more torque (albeit a lower driveshaft speed) from the driveshaft compared to the 3.92.Those people saying shifting down a gear will increase strain on the transmission are making up stuff and calling their ideas "physics".
If you want to try debating the physics of it, go ahead. My degree may be in electrical engineering, but I still did quite well in physics, dynamics and statics. Still had to know those things to take the professional engineering exams to get my license.