Internal combustion

As noted by LiquidPiston, internal-combustion hasn't gotten much better in a century. Any "efficiency" improvements have been around reducing air-resistance and lightening the chassis or, at best, shifting some of the power needs to the battery. I've been looking into the battery improvements especially - and so has Europe, whose masters plan to ban combustion entirely.

With the exception of Porsche. Whose bright idea is to use methanol instead - "eFuel!!". (I'm just glad they didn't call it "smartfuel".) I hasten to tout that this will work ... for rovers on Mars, where there is no petroleum. Down here on Earth, Major Tom, gasoline is cheaper and will always be cheaper.

I do like that LiquidPiston have brought the sheer mass of the engine from 39 lb to 4.5 lb, using a "rotary" model instead of combustion. This presents a challenge for us battery-touters because, current cell alpha is stinky (tho' getting better, and can be incorporated into the rest of the chassis).