Eli5: 2 cars have the same Horsepower but different engine in terms of displacement (2.0L TDI vs 3.0L TDI) but what difference does it make and which one is better?
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Horsepower and engine size don’t account for gear ratios, turbo/super charging, or importantly, weight.
Horsepower and engine size don’t account for gear ratios, turbo/super charging, or importantly, weight.
Engines can be rather complex, and there’s a number of factors that go into which engine is “better” which is pretty arbitrary to begin with. One engine might be more efficient (which can be considered “better” even if it’s slower. One might be more powerful/faster (“better”). One might be lower displacement and turbocharged, one might be more reliable (cheaper is “better” too).
Now specifically to the two engines you mentioned, one has more horsepower than the other unless you’re comparing different years, so could you provide a different example?
Engines can be rather complex, and there’s a number of factors that go into which engine is “better” which is pretty arbitrary to begin with. One engine might be more efficient (which can be considered “better” even if it’s slower. One might be more powerful/faster (“better”). One might be lower displacement and turbocharged, one might be more reliable (cheaper is “better” too).
Now specifically to the two engines you mentioned, one has more horsepower than the other unless you’re comparing different years, so could you provide a different example?
Well in your example, the 2.0 is a 4 cylinder engine and the 3.0 is a 6 cylinder engine. More pistons means more displacement, which means more air getting sucked into the engine for each revolution of the crankshaft, which also requires more fuel to create the proper air/fuel ratio. All of that generally means more power, and lower fuel economy. Basically, a bigger engine will make more power, over a more usable RPM range, while using more fuel.
Well in your example, the 2.0 is a 4 cylinder engine and the 3.0 is a 6 cylinder engine. More pistons means more displacement, which means more air getting sucked into the engine for each revolution of the crankshaft, which also requires more fuel to create the proper air/fuel ratio. All of that generally means more power, and lower fuel economy. Basically, a bigger engine will make more power, over a more usable RPM range, while using more fuel.
Engines can be rather complex, and there’s a number of factors that go into which engine is “better” which is pretty arbitrary to begin with. One engine might be more efficient (which can be considered “better” even if it’s slower. One might be more powerful/faster (“better”). One might be lower displacement and turbocharged, one might be more reliable (cheaper is “better” too).
Now specifically to the two engines you mentioned, one has more horsepower than the other unless you’re comparing different years, so could you provide a different example?
The smaller displacement engine will be smaller and thus lighter, giving more power per weight. But for the same power the smaller engine needs to rev higher and/or have a higher compression ratio, both of which might have an effect on the durability / running costs of the engine.
Larger displacement engine might also have a less steep power curve, i.e. more power at lower rpm than on the smaller engine, which could be better in something like offroad or towing applications.
The smaller displacement engine will be smaller and thus lighter, giving more power per weight. But for the same power the smaller engine needs to rev higher and/or have a higher compression ratio, both of which might have an effect on the durability / running costs of the engine.
Larger displacement engine might also have a less steep power curve, i.e. more power at lower rpm than on the smaller engine, which could be better in something like offroad or towing applications.
Horsepower and engine size don’t account for gear ratios, turbo/super charging, or importantly, weight.
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