There are other things. For example: Teslas improve general efficiency considerably by (for example) using regenerative braking, which will be utilised in norm

There are other things. For example: Teslas improve general efficiency considerably by (for example) using regenerative braking, which will be utilised in normal driving but not if you're travelling up a big hill on a freeway. Furthermore, they're particularly heavy cars - a Ford Fusion (similar sized saloon) is about 1500kg, whilst the Tesla is 2100kg, presumably because of the batteries - the extra effort to lift up a hill is linear in the weight, so it'll be at least a 25% drop in the surplus cost over normal driving. Overall, it's not really an efficiency thing because the costs of fuels vary so much. For pure heat-to-wheel efficiency, the most important one is that since Teslas are about 80% efficient at turning power into motion, and charge efficiency is about 97%, and a combined cycle power station is about 55% efficient at converting heat energy into power, then the total efficiency from heat to wheel is about 43%, whilst a modern petrol car might be expected to see more like 30%.