My car legitimately takes less fuel at 90 than 30. It’s the whole accelerating to 90 part that takes significantly more fuel, but steady state, 90 is more efficient than 30.
This is all because of how internal combustion engines and transmissions with distinct gear ratios work. Even if you’re not moving, you’re going to use some amount of fuel to keep the engine running, right? The engine has a bunch of internal friction that needs to be overcome. That bare minimum is more significant at low speeds. And then to raise the engine speed, you’ll have to add a bit more fuel. When you shift up a gear, the engine speed goes down - and up to some speed, this is so significant that it affects fuel economy. Then once you get to higher speeds, the energy required to overcome wind resistance is the most important bit and that has a quadratic growth.
CVTs eliminate these sharp rises and drops in fuel consumption since they have no gears, but they have their own issues and even they don’t get rid of the baseline fuel consumption to keep the engine running. EVs eliminate all this nonsense altogether, which is one of the reasons why an EV is significantly more efficient in the city while an ICE is significantly more efficient on the highway (the other reasons are lack of idle and, of course, regen braking).
If you don’t want the issues of CVTs (which are essentially none if you lease a car and don’t give a fuck about it beyond the 3-5 years you use it and also aren’t an enthusiast), modern 8 and 9 speed transmissions are better than older transmissions here. They have more different speeds where the engine is in an optimal RPM range. You still don’t want to go TOO slow (think about it - fuel consumption of a car idling at standstill is essentially infinity liters per 100 km because you’re dividing X amount of liters by zero kilometers - as you approach zero speed, you approach infinite fuel consumption).
Realistically, the optimal speed for fuel economy with an internal combustion engine and no hybridization tech is probably somewhere between 40-80 km/h. The exact number depends on a bunch of factors.
My car legitimately takes less fuel at 90 than 30. It’s the whole accelerating to 90 part that takes significantly more fuel, but steady state, 90 is more efficient than 30.
This is all because of how internal combustion engines and transmissions with distinct gear ratios work. Even if you’re not moving, you’re going to use some amount of fuel to keep the engine running, right? The engine has a bunch of internal friction that needs to be overcome. That bare minimum is more significant at low speeds. And then to raise the engine speed, you’ll have to add a bit more fuel. When you shift up a gear, the engine speed goes down - and up to some speed, this is so significant that it affects fuel economy. Then once you get to higher speeds, the energy required to overcome wind resistance is the most important bit and that has a quadratic growth.
CVTs eliminate these sharp rises and drops in fuel consumption since they have no gears, but they have their own issues and even they don’t get rid of the baseline fuel consumption to keep the engine running. EVs eliminate all this nonsense altogether, which is one of the reasons why an EV is significantly more efficient in the city while an ICE is significantly more efficient on the highway (the other reasons are lack of idle and, of course, regen braking).
If you don’t want the issues of CVTs (which are essentially none if you lease a car and don’t give a fuck about it beyond the 3-5 years you use it and also aren’t an enthusiast), modern 8 and 9 speed transmissions are better than older transmissions here. They have more different speeds where the engine is in an optimal RPM range. You still don’t want to go TOO slow (think about it - fuel consumption of a car idling at standstill is essentially infinity liters per 100 km because you’re dividing X amount of liters by zero kilometers - as you approach zero speed, you approach infinite fuel consumption).
Realistically, the optimal speed for fuel economy with an internal combustion engine and no hybridization tech is probably somewhere between 40-80 km/h. The exact number depends on a bunch of factors.