Why does farming equipment require such low horsepower compared to your average car?
Because speed is not needed as it is in a car for example, gearing between turns of the engine and rotation of the wheels or equipment can be very low.
They go at pretty slow speeds so the engines are built around high torque and long term reliability
At low speeds, power scales linearly with speed so pulling a plow that takes 1 ton of force at 10 mph requires half as much power as pulling the same plow at 20 mph. If you’re only ever going to pull that plow at 10 mph you don’t need a huge amount of power, lots of farming equipment doesn’t work if you pull it too fast.
Cars and trucks need to get up to highway speeds over a relatively short distance, this is really why we put 100+ horse power in everything these days. You only need about 30 hp to cruise on the highway but doing 30-70 on a short onramp to get up to a safe speed requires quite a lot more power.
Torque is the actual power of the engine. Horsepower is the rate at which it is produced. Farm equipment is slow, so with a relatively “weak”, low Horsepower, high torque engine, you can get a lot of work done. Heavy flywheel, low revs, almost always diesel, which are big heavy engines with a lot of torque. The right gearbox and the job’s done. Nobody’s winning any races in a tractor but it can certainly pull a load.
Modern cars are ridiculously overpowered. Every year, the new models need to be better than the old models and better than the competition.
Farm equipment just needs to get the job done. A tractor rarely needs to work at more than 5 mph. So no reason to spend money on a larger engine.
Most commercial equipment has a lot less hp than you’d expect. When whoever is buying equipment is looking at operating costs, purchase price, expected profit, they buy just what they need, not what is most fun.
Most consumers on the other hand think, I may tow a trailer in the mountains one day, so I’d better get the bigger engine just in case. Commercial operators say put it in 2nd gear and go slow.
Because farming equipment requires more torque than horsepower. This torque is usually provided from diesel engines and special gear ratios.