I'm trying to figure out where this figure comes from. The immediate source is the Institute for Energy Research, which seems to be a lobbying organization for the oil and gas industry.<p>Not clear what "efficient" means in this context. All heat engines have a second law of thermodynamics efficiency limit. Cars run 20%-40% efficient, measured by dynamometer output at wheels / energy content of fuel.[1] (Motor Trend says 20%. [2]) Electric cars aren't limited in that way, and reach 63%-80%. Of course, if fuel was burned to create electricity, there was a thermodynamic efficiency loss upstream. Those values have objective engineering measurements.<p>There's something called "Miles Per Gallon Equivalent".[3] This is more of a marketing/regulatory term. It appears on car window stickers. It's just miles per kilowatt hour multiplied by kWh per gallon of gasoline, which is 33.7 kWh / gallon. Motor Trend says that the Tesla Model 3 is rated at 142 MPGe, which is a reasonable number.<p>This probably has to do with pollution credits, not energy efficiency. It's may be related to the Corporate Average Fuel Economy rules. Those have a big loophole on the gasoline-powered side - there are different limits for "cars" and "light trucks".[4] US vehicle production is currently over 50% "light trucks", which includes many SUVs.<p>[1] <a href="https://en.wikipedia.org/wiki/Engine_efficiency" rel="nofollow">https://en.wikipedia.org/wiki/Engine_efficiency</a><p>[2] <a href="https://www.motortrend.com/news/evs-more-efficient-than-internal-combustion-engines/" rel="nofollow">https://www.motortrend.com/news/evs-more-efficient-than-inte...</a><p>[3] <a href="https://www.motortrend.com/features/what-is-mpge-meaning" rel="nofollow">https://www.motortrend.com/features/what-is-mpge-meaning</a><p>[3] <a href="https://www.kbb.com/car-advice/what-is-mpge/" rel="nofollow">https://www.kbb.com/car-advice/what-is-mpge/</a><p>[4] <a href="https://en.wikipedia.org/wiki/Corporate_average_fuel_economy" rel="nofollow">https://en.wikipedia.org/wiki/Corporate_average_fuel_economy</a>