Like a Ford Crown Victoria vs a Honda Civic.
In: Engineering
The second generation Crown Vic we all know and love weighed 4,057 lbs, and made a maximum of 250 hp in 2004 for the Police Interceptor model. That’s a power to weight ratio of 123.2 hp per ton.
The 10th generation Honda Civic weighs 3,003 lbs at most, and the Type R makes 306 hp. It has a power to weight ratio of 203.8 hp per ton.
Of course, these are peak numbers, the worst weight figures and the best engine figures I could find per generation. Peak numbers don’t mean much, but the power to weight ratio highlights how we’re comparing apples to oranges here. Other things one would want to take into account is the torque curve, aerodynamics, suspension, traction, throttle response, gearing, power bands, volumetric efficiency, etc.
You’re comparing a light car with a powerful, tuned engine to a very large and heavy car with a big, heavy, older engine that was designed in it’s era to meet different target requirements, and high power output wasn’t one of them. The principle motivator for Ford was they had been heavily invested in their production lines for a long time, and management in that era wasn’t willing to change in the face of a market that was willing to tolerate their dated practices. Now days, large and inefficient engines that weren’t even built that well are not tolerated and the car was discontinued. They’ve been forced to innovate as a last resort. And also appreciate Ford is not a domestic brand, they’re international. They make most of their money selling overseas, so that the international market is no longer buying their dated garbage is what is forcing them to innovate. It’s really a complex problem of how these cars existed and for so long. You can buy Ford parts anywhere in the world and you can get your car running. If you start changing your supply chains, you disrupt your markets that are heavily invested in your product for that reason. But now that countries are coming out of poverty the world around, and many more resources are becoming more accessible, they can demand more, and own more luxury brands.
Older cars were far less efficient. In the 70s, there were 7.0 liter v-8s that made less than 200hp. As technology has advanced, we’ve learned to get more and more power out of smaller and smaller engines, couple that with lighter materials in the build process, better aerodynamics and you get faster, more reliable cars. Not all car platforms are using the latest AMD greatest tech, in fact some cars are still built on 15-20 year old platforms, so you’ll get a lot of efficiency variance.
Larger engines and more pistons don’t necessary translate to more power and speed.
There’s a lot of factors involved here; combustion concept, is the engine Super or Turbo charged, what kind of fuel, alloys used, displacement, etc. Basically you can design a 4-cylinder engine to be more powerful than and 8-cylinder and vice versa.
Also 4-cylinder engines are smaller and lighter, and lighter cars can go faster.
One thing to note is arguably the most powerful racing car engine ever built, the BMW M12, was a 4-cylinder Turbocharged engine.
Assuming everything else is equal, a 4 cylinder would not make more power than a V8. You need to compare everything as the same. A 4 cylinder Camaro vs a V6 Camaro, vs a V8 Camaro. Not a Crown Vic vs a Civic. Different cars have different aerodynamics. More air resistance would mean a slower car. A different gearbox can put that power to the wheels differently. Forced induction or NOS will make more power.
You also need to look what the car is designed for. If it’s designed for fuel efficiency vs acceleration, vs top speed vs towing/hauling power.
That’s not even all of it.
It’s all about power to weight ratio’s. A 200hp car weight 2000lbs will have the same power/weight ratio as a 400hp car weighing 4000lbs which is 0.1 horsepower per pound of weight. When these numbers differ, you get a car that is either faster or slower. Power is only have the equation, and most people only notice/look at power and never take into account the weight of a vehicle.
More modern engines get more power from the same amount of engine displacement. Old-school V8s were really lazy engines. Massive displacement did not translate into massive power.
Look at formula one cars, they’re using hybrid V6 engines and theyre fast a fuck.
It’s all about engine tuning and weight.
There was a time where V10 and V12 F1 cars raced together but their engines were tuned in such a way they had almost the same performance on paper.
Forced induction. An engine makes power by burning fuel. It can only suck as much air as the engines volume allows per revolution. Add boost (forced induction) and it can combine more air with more fuel and make more power. There are trade-offs such as less torque, less longevity, the need for higher octane fuel… but in a nutshell more air + fuel = more power.
Larger cylinders, higher RPMs, and more boost all increase power output. These can be used to drive an i4 at way higher power than a v8, although a v8 with similar additions would still be more powerful.
Having more cylinders does not necessarily mean more power. For example Cameros from the 90’s only had 160 HP. Some 4 cylinder engines are capable of high horsepower such as a Subaru STI which could have up to 300 HP.
Weight is also a major factor . V8 engines are quite heavy. And the cars they power are generally larger.
Where as a car with a 4 cylinder engine is *usually lighter which helps improve speed and acceleration.
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