Why is the relationship between torque horsepower and RPM not linear In automobile terms.?

Answer 1

It is, Horsepower = Torque x RPM, but Torque is not constant across the rev range of an engine. For gasoline engines, there is generally very little torque at low rpms, generally flat torque across the middle rpms, and then a drop off as the engine starts spinning too fast for complete combustion. Electric engines, on the other hand, start off with maximum torque and decrease with higher engine speed. So, the short answer to your question is that it's a direct relationship between horsepower and torque, but the variation in the torque curve across the rpm range makes the resultant horsepower curve vary too. (If your question was really why does torque vary with rpm, simply stated it's because engines have varying efficiencies at different speeds.) It is, Horsepower = Torque x RPM, but Torque is not constant across the rev range of an engine. For gasoline engines, there is generally very little torque at low rpms, generally flat torque across the middle rpms, and then a drop off as the engine starts spinning too fast for complete combustion. Electric engines, on the other hand, start off with maximum torque and decrease with higher engine speed. So, the short answer to your question is that it's a direct relationship between horsepower and torque, but the variation in the torque curve across the rpm range makes the resultant horsepower curve vary too. (If your question was really why does torque vary with rpm, simply stated it's because engines have varying efficiencies at different speeds.)

Answer 2

The relationship between torque, horsepower, and RPM in an automobile is not linear because torque and horsepower are related through the equation: horsepower = (torque x RPM) / 5252. Since torque and RPM do not increase or decrease at the same rate, the relationship between all three variables is not linear. Torque typically peaks at lower RPMs, while horsepower peaks at higher RPMs in internal combustion engines.