> A gas engine could certainly tow my race trailer, but at horrific mpg Gasoline engines actually have their highest fuel-to-power efficiency at full throttle.

> A gas engine could certainly tow my race trailer, but at horrific mpg Gasoline engines actually have their highest fuel-to-power efficiency at full throttle. A more powerful engine just allows you to burn even more fuel to accelerate faster. I suspect that the gas trucks gear ratios just made it unsuitable for towing by putting you way outside the optimum power band at load. This is why I said that power is not the only factor: You need a chassis, brakes, gear ratios and possibly transmission cooling for suited for towing that heavy loads. I stretched a chassis once towing way over the rating - I recommend not doing that. 22 MPG is also pretty bad by today's standards, but I've had engines like that. At 12mpg you're getting very close to the fuel consumption of the compact 48 ton trucks we use in the EU, but they usually have almost 800 HP under the... seat. > EGR "messing with" does affect power. EGR lowers combustion temps .. but let's at least be honest about the negatives. Temporarily, at idle, it does lower efficiency yes. But it's during the phase of engine operation with the lowest possible fuel consumption, and while all the fuel you're burning is thrown out the window. It is also only fully open in a very specific scenario, and otherwise at idle or very low power demand it will only be slightly open. I don't think the cooled cylinder is harmful - it would eventually cool that that temperature at idle even without the EGR, and a hot cylinder preheats gasses on the way in, reducing the possible temperature gradient. > But I don't buy that there aren't other ways to solve these issues. As mentioned in a different comment, the EGR efficiency concern is entirely gone with engine start-stop as the time when it would be fully open is replaced by the engine being off. That improves fuel consumption past a deleted truck. I agree that emissions-related tech is a hack in many ways, but the problem is that internal combustion engines are terrible and hard to fix. For most people, electric already works fine, and most complaining about spec comparisons never need those specs. For others, older technology will stick around for a bit longer until we have mature solutions. Plus, if all regular cars and trucks get replaced by something better, having a few (properly emissions controlled) gas trucks on the road won't matter as much.