regarding car performance, both torque and hp affect it although more in adverse or vice versa effect. cars with good torque will usually take off faster from a standing start. those with higher hp but low torque will need longer roads to build up speed. engine size and transmission also play a big factor.

good example will be the 1600 civics and corollas from the 90's, the rollas would usually pull stronger during the lower rpm range but then the civic will catch up once the rpm's start to build up.

main reason is that rolla engine blocks have longer strokes for better lower rpm torque but they have lower rev limits and compression ratios, limiting power production in the higher rpm range. i have a friend who had the head of his corolla shaved to give the engine a higher compression ratio then a full free flow exhaust allowed to engine to rev a lot higher. if you happen to be drag racing in libis aound year 2000, this is the flat black corolla that could smoke civics.

civic engine blocks on the other hand have shorter strokes, it needs to rev high in order to produce power but generally lack torque in the lower rpm range. good thing hondas are generally lighter kya hindi kailangan ng big torque sa low rpm. and mas efficient din ang transmission ng honda kaya konti lng ang power loss from the engine to the wheel.

big engines are another story. they do not need to be revved high bcoz they already develop good torque and power even from low rpms. this is due to the sheer volume of air and fuel that combusts in the chamber with each cycle of the engine. ang pinaglalaruan na lng nila ay yng transmission and gearing in order to effectively transfer the power to the wheels and carry the weight of the vehicle.

newer engines though are totally different. almost all new engines now have valve timing technology and advanced ecu's of some sort to manage power production, output and fuel efficiency. usually displacement and rev limit n lng ang responsible sa final output ng engine.

hope this helps mga pips.