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drafterman t1_j6d5301 wrote

There is only a finite amount of energy in fuel to be extracted to begin with. That places an upper limit on what your MPG can even be. So it can't simply go up forever without limit. And Whatever that limit is, there are diminishing returns meaning you get less and less an improvement over time.

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Old_timey_brain t1_j6d5ghw wrote

Compared to what I was driving in the early 1970's theyare much more efficient.

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slaqz t1_j6d9r8h wrote

Fuel injection helped alotcwith that

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GoneIn61Seconds t1_j6d9zh3 wrote

I’m the early 80s, Datsun hatchbacks were rated at 42mpg Highway. In the late 20’s you could achieve 25mpg in a Ford. Neither was very safe or luxurious though.
While I’m amazed by the low emissions of modern engines, we should have better mpg by now. Too many amenities, weight, etc on newer cars for my taste.

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on_the_nightshift t1_j6dbnr6 wrote

Much of the weight is driven by federally mandated safety standards

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kyrsjo t1_j6dddtj wrote

Also, there just isn't that much more you can do with an ICE engine - it's burning fuel to raise the temperature to generate overpressure which pushed pistons that turn "pedals", which then act through a complicated set of gears and linkages. Whatever you do, it's never going to be super efficient, most of the energy is lost to heating the coolant. And it's a technology that lots of people have already spent a lot of effort on optimizing, meaning most out the easy gains are long gone. Also, it needs to be fairly light and cheap to fit in a car, and work at a wide range of RPMs, torques, power levels, and it has to be reliable and not too complex.

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Deil_Grist t1_j6dggrm wrote

Some cars do gain a few MPG when you go for lower / base trims. I know the Kia Niro and Hyundai Ioniq (not Ioniq 5) do.

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SkateIL t1_j6d8qag wrote

This is why only dingdongs believe that the oil industry bought up special 100mpg carburators. There is only so much energy in a gallon of fuel and it's going to take x amount of energy to move a weight down the road.

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on_the_nightshift t1_j6dc05y wrote

Nothing like chemistry and physics to put a damper on a good conspiracy theory

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Deil_Grist t1_j6dgtkx wrote

2/3 of the energy of an average ICE is lost as heat and noise. The main limiting factor is the size constraints of ICE don't allow it to use that heat the same way a power plant can, hence why round trip fuel /carbon efficiency of BEVs are so good even when the electricity comes from fossil fuels.

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