Do car enthusiasts obsess too much about horsepower? The always insightful Jason Fenske of Engineering Explained has some compelling thoughts on the matter.
Horsepower: You can’t ever have too much, we gearheads like to say, maybe if we don’t really and truly mean it in every instance. Horsepower is an excellent bragging point—sort of like how much weight you can press in the gym, as Jason Fenske notes in the recent episode of Engineering Explained we’re sharing here.
But hold on for a moment. We know the horsepower rating for any vehicle is a peak value, a single pinpoint on a chart that spans the engine’s useful operating range. It’s not a complete picture of the engine’s available output by any means. And it doesn’t reflect all the other important attributes in an engine, including drivability and smoothness. And anyway, raw power is just one angle to the total performance picture, Jason observes. For example, if the vehicle can’t put all the power to the pavement, it won’t result in useful acceleration.
And as Jason shrewdly notes in the video, “horsepower is heavy.” Big powerful engines are great, but they’re big and heavy, and they require bigger, heavier drivetrains, brakes, suspension—in fact, bigger and heavier everything in a production road car. And in performance, weight is our nemesis. To send the point home, here Jason is driving a new Mazda Miata MX5. With just 181 hp, the Miata is far from the most powerful car on the market. These days, it’s nearly in the peashooter class. But at less than 2.400 lbs, it’s a very capable performer, and one of the most enjoyable cars you can find in the showrooms today. Jason has more to say on the topic, and now we’ll let him say it. Video follows.
The power to weight ratio is that hidden factor that can make the performance of any vehicle. The 1966 Mustang I had was such a good example of this.
Great points, thanks for sharing.
Horsepower is very subjective. How and where it is made a major thing. Take say 500hp, a small turbo engine can make that but in a fairly narrow power band and often not that useable. A 500hp V8 does it very easily with excellent driveability. Put the two together and taking into mind the V8 car will generally be heavier the V8 is usually quicker.
Though the small turbo engine often is not much lighter with all the accescories, turbo and plumbing, intercooler etc. And the transmission will be the same weight generally.
The MX5 with a quite toy engine [these days] is still sort of light so is quite qick as you can use the power harder and earlier. Dragstrip though would be slow, road race on par with many bigger engined cars.