spark82
Member
Guys, I really don't want to go deep into physics, but as an engineer I might, and I'm not a native speaker so I don't always know the right terms, and for all of that please forgive me. 
As for burning fuel, all that matters is that you have an engine that converts the remains of dinosaurs into rotation, and one must note that its efficiency is pure cr*p considering the best 4-stroke Otto engine have an efficiency of 30%, diesels top at about 50%, while electric motors may be above 90%. The input is the energy contained in the gasoline and the output is the torque multiplied with the rpm on the crankshaft. OK, knowing this you move on, subtract the energy wasted in the gearbox and the chain drive, and you get the energy that actually moves you forward. And here comes the trick. If you accelerate from 30 mph to 40 mph, let's say you need one unit of energy. One might think that if you accelerate from 40 to 50 mph, you need the same on unit of energy again. And it's not true... You need more than 30 percent more, so about 1,3 units of energy. And that means that if you decelerate from and to the same speeds then you have to "waste" (convert to heat with your brake pads and discs) the same amounts. So you lose the energy twice. And it's waaay worse with higher speeds. And the reason is that the energy you need to move is not in linear correlation with the speed, it's is in correlation with the squared speed.
And aerodynamic drag is also dependent on the squared speed... Speed is a b*tch, ain't it? Gives itself only at expensive prices. And let's not take that bastard Einstein into condideration, lucky his findings are only relevant when you are closing in on the speed of light.
As for burning fuel, all that matters is that you have an engine that converts the remains of dinosaurs into rotation, and one must note that its efficiency is pure cr*p considering the best 4-stroke Otto engine have an efficiency of 30%, diesels top at about 50%, while electric motors may be above 90%. The input is the energy contained in the gasoline and the output is the torque multiplied with the rpm on the crankshaft. OK, knowing this you move on, subtract the energy wasted in the gearbox and the chain drive, and you get the energy that actually moves you forward. And here comes the trick. If you accelerate from 30 mph to 40 mph, let's say you need one unit of energy. One might think that if you accelerate from 40 to 50 mph, you need the same on unit of energy again. And it's not true... You need more than 30 percent more, so about 1,3 units of energy. And that means that if you decelerate from and to the same speeds then you have to "waste" (convert to heat with your brake pads and discs) the same amounts. So you lose the energy twice. And it's waaay worse with higher speeds. And the reason is that the energy you need to move is not in linear correlation with the speed, it's is in correlation with the squared speed.
And aerodynamic drag is also dependent on the squared speed...
Speed is a b*tch, ain't it? Gives itself only at expensive prices. And let's not take that bastard Einstein into condideration, lucky his findings are only relevant when you are closing in on the speed of light. 
