Found the article below:

https://cleantechnica.com/2018/03/10/electric-car-myth-buster-efficiency/

the salient paragraphs:

".... Conventional gasoline vehicles only convert about 17%–21% of the energy stored in gasoline to power at the wheels.”

...

An electric motor typically is between 85% and 90% efficient.

...

In a recent post for Quora, Brian Feldman, a robotics expert and entrepreneur, offered this explanation: “Consider the Tesla Model S, which has an available 85 kWh battery and a 265 mile range. Consider a similar gas-powered car, which gets 35 mpg. Gasoline contains about 33 kWh of energy per gallon. The Tesla uses 320 Wh/mile of energy (85 kWh/265 miles). The gas powered car uses 940 Wh/mile of energy (33 kWh/35 miles). Once the energy is on board (not counting the efficiency of the power generation, oil refining, or charging), the Tesla is using only about a third as much energy as the comparable gasoline-powered car.”

Heres my problem with the posted paragraphs.

it states an electric car can travel 265miles on an 85kWh charge. (320Wh/mile)

and petrol does 35miles per 33kWh. (940 Wh/mile)

But doesnt that imply 100% energy extraction?

I mean, if you have an 85kWh battery, and it is 90% efficient, you can only travel (265 * 0.9) miles = approx 230 miles.

If a petrol engine is only 20% (I know it says 21%!) efficient, then 33kWh gets you 20% of 35 miles, which is 7 miles.

Have I lost my ability to do arithmetic?