Halfway to Perfect: The Shocking Efficiency of Excellence

Halfway to Perfect: The Shocking Efficiency of Excellence

The efficiency of Electric Cars is much greater than gasoline or hybrid vehicles. Although everyone knows this, few know that this results in unexpected and counter-intuitive impacts on range and performance.
The average car engine efficiency is 20 to 25 percent. This is not a result of poor engineering; far from it. The modern internal combustion engine (I.C.E.) is the result of over a hundred years of continuous development and billions of dollars of research. This low efficiency is due to acceleration performance design choices and hard limits imposed by the laws of Thermodynamics. The most efficient gasoline engine is currently made by Toyota and achieves a thermal efficiency of about 40 percent. I.C.E engines are very close to as good as they are ever going to get.

Nearly all electric vehicles have motor and drivetrain efficiencies of over 90%. Higher efficiency is a good thing but it also ruthlessly exposes poor engineering design choices under real-world conditions. Let’s consider a few hypothetical electric vehicles driving down the highway on a road-trip, each of which have identical 50 KWH battery packs.

Government Motors Blue Car = 92% Efficiency = 150 mile range
Lantern Limited Green Car = 96% Efficiency = 300 mile range
Stark Industries Red Car = 98% Efficiency = 600 mile range
Wayne Industries Black Car = 99% Efficiency = 1,200 mile range

How much farther can the Green Car go than the Blue Car? The answer is 100 percent! Double the range on the same amount of energy! The Red Car is twice as good as that but only half as good as the ultimate Black Car. Small differences in efficiency between 90% and 100% = HUGE differences in range and/or battery size/cost.
It has been estimated that at 75mph on the highway on level ground on a windless day, the Tesla Model S energy expenditure is due to:

72% Wind Resistance
21% Tire Rolling Resistance
7% all other losses combined

This is not because the Model S has poor aerodynamics, far from it. The Model S has a CdA (Aerodynamic Drag Coefficient) of 6.2 square feet which is very good and actually identical to a Third Generation Prius. At highway speeds the range per KWH is almost entirely dependent on the aerodynamic shape/size of the electric car and the quality/alignment/inflation of the tires. Current Auto Manufacturers who are used to operating in the low 25% efficiency range are not used to holding themselves to high standards of excellence in this regard. A 92% efficient vehicle is an incredible improvement over current 20 - 25 % vehicles. But any traditional auto manufacturer who brings their “A game” to the arena of A+ and A++ electric vehicles will find themselves humiliated in terms of efficiency, range and performance.

Case in point: the 2016 GM Chevy Bolt vs. 2017 Tesla Model 3 vs. the 1996 GM EV1.

GM Chevy Bolt Coefficient of Drag of 0.312 multiplied by frontal area of 25.8 sq ft, = CdA 8.05 sq ft
Tesla Model 3 Coefficient of Drag of 0.21 multiplied by frontal area of 20.6 sq ft, = CdA 4.3 sq ft
GM EV1 Coefficient of Drag of 0.19 multiplied by frontal area of 20.8 sq ft, = CdA 3.95 sq ft

The wind resistance (CdA) of the GM Chevy Bolt is more than double that of their 20 year old discontinued-and-crushed-with-extreme-prejudice EV1. Since range/efficiency at highway speeds is overwhelmingly dependent on this number, it is safe to say that the GM Bolt will be seen as a competitive failure once the Tesla Model 3 comes to market and its final specs and efficiencies are revealed.
It could be argued that this only affects electric cars driven at high speed on long distance trips. But this misses the greater point. I.C.E. cars are so inefficient and require so much maintenance in comparison to electric that the mentality, corporate culture, and business model of car manufacturers, dealers, and repair shops is out-of-step and incompatible with the new technology.

The question has been asked: Why does Google exist? Why didn’t Microsoft dominate the internet search business as it was perfectly positioned to do? Why does Facebook exist? Why didn’t Google dominate social media as it was perfectly positioned to do? Kodak invented the digital camera. Why then was Kodak bankrupted by it?
The Lithium-Ion battery was invented at Exxon (an energy company which specialized in Oil) in 1976. The first modern electric car was made by GM (a car company which specialized in I.C.E. cars) in 1996. The first car capable of fully autonomous driving (pending software update) was made by Tesla in 2016. The next 20 years will be the most exciting of all.

andy.connor.e | February 15, 2017


Frank99 | February 15, 2017

Waiter, I'll what jdlindskog is having...

Not only is that nearly incomprehensible, it's mathematically illiterate - I'm not sure that even one of the calculations shown are correct.

I do, however, agree with the final sentence.

dsvick | February 15, 2017

My brain hurts ...

bmalloy0 | February 15, 2017

Anyone else reminded of Billy Madison?

andy.connor.e | February 15, 2017

i.imgur. com/S0KosHO. jpg

luwong.8888 | February 15, 2017

I can simplify this. The Bolt has a drag co. of 0.31 and with the 60KWh stated size, a few youtube's have already achieved over 270 miles and one guy getting 300 miles on a single charge. That is crazy high and the youtube poster admits to driving very carefully but not hypermiling it (yeah, whatever, 300 miles on a single charge is hypermiling).
The M3 with the stated 0.21 (that is an awesome number) drag co. and a 60KWh should get 230 miles easy and probably 320 miles by hypermiling it. Then again, Tesla's electric drive is more towards performance and the company readily admits to giving up on not being the most efficient to not having to drive boring vehicles.

andy.connor.e | February 15, 2017

I want 1200 miles of range according to OP

luwong.8888 | February 15, 2017

Only Bruce Wayne knows the formula for 1200miles.(only 1 seat cause he only has 1 butt) I am happy with a 180 mile range in the middle of winter (-10C) with all the heat on commuting at 110kms/hr on the highway.

andy.connor.e | February 15, 2017


i dont think the range degradation is even that extreme. Check Model S, but cant wait till the numbers come out.

massimob30 | February 15, 2017

I cannot unread this.

luwong.8888 | February 15, 2017

I have played with the range degradation, I used 110kms/hr at -10. The numbers are good, and I added another 10% to match real world conditions. If the M3 offers a cold package (heated steering wheel and heated seats) for $1500, I am all in. But if it is like $3000 but that includes a pano roof and fog lights, etc. I will not purchase. Then I will use the heater and warm the entire cabin. I know, not the most efficient. Have one neighbour with a MS70 and his range drops 15-30%(mild winter to full on -20C) in the winter. He likes having his car hot inside. Another neighbour has what I think is a MS60. The rear of his car just says Tesla, no numbers, weird. He did go with the extreme winter package and his interior is ice cold except his driver seat and the steering wheel. He does not see a noticeable drop, less than 10%, he tells me. Since my commute is 42kms one way, 180 miles with the car's heat cranking is way more than I need.

kzodz | February 15, 2017

bmalloy0 -> 100% We are all dumber for having read a sentence of that nonsense!

andy.connor.e | February 15, 2017


lets make fun of the commenters when there is this forum topic

Red Sage ca us | February 15, 2017


I think the Toyota Prius might manage 36% efficiency. The average performance oriented ICE vehicle has 12% or less efficiency. Fully electric cars manage to be performance oriented while being better than 88% energy efficient.

The OP seems to be arguing with himself. Weird. Beyond that, I don't really wish to comment further.

djharrington | February 15, 2017

Life in logarithms