Let's face it, the Environmental Protection Agency's (EPA) miles-per-gallon-equivalent rating (MPGe) is a good estimate, but an estimate nonetheless. Battery-powered electric cars don't burn gasoline, so a gasoline-based rating is always going to be a theoretical exercise in energy conversion.
Still, the EPA needs some way to compare electric, hybrid, and gasoline-burning vehicles. Such ratings benefit government agencies and auto companies, as well as consumers who would otherwise struggle to compare kilowatt-hours to gallons consumed. The EPA reaches its hybrid and electric vehicle figures by running test cycles, determining how many kilowatt-hours are burned, converting it to BTU/mile, and then dividing that number by the BTUs in a gallon of gasoline. The result is the MPGe figure, which will undoubtedly be a source of technical arguments for years to come.
Click on the image below to see 12 of the top fuel-efficient vehicles, as determined by the MPGe rating system.
Ford Transit Connect EV -- 62 MPGe (combined city + highway): Ford's Transit Connect is a utility van with a top speed of 75 mph and an all-electric driving range of 80 miles. (Source: Ford Motor Co.)
In addition to a cost per mile formula (which would vary dramatically geographically), I'd like to see the cost of the vehicle rolled into the equation. Since the EVs are 3 to 4 times the cost of their comparable internal combustion engine counterpart, total cost of ownership is an important metric. I may save $100/month on fuel/energy, but if my loan payments are $300/month more, does the EV make sense when I'm already scraping by financially? Then there is the inevitable battery replacement at year 5 to 7. How does that enter into the equation?
@rjnerd: If you'r needing a vehicle to carry stuff, have you looked at the Prius V? It seems like they're billing at as a Prius for the light-duty hauler set. I have a scenic painter in the family and we are always transporting stepladders, little folding scaffolds and painting supplies and our aging Volvo V70 wagon is slowly falling apart. I plan on test driving a Prius V as soon as I get a free weekend. It won't carry a 4x8 sheet of plywood but then I have friends with pickups for that.
I also agree, I want to know how much it will add to my electricity bill each month to plug-in a car. The manufacturers only seem to talk about the gasoline fuel economy...not the higher electric bill.
With the much higher cost of hybrid and electric cars, and my low miles driven per year (just 6K), I just purchased a new conventional gasoline-powered economy car. Now it seems like I hardly use any gas, and I'm glad I didn't add to my already super-low monthly electricity bill ($60/month).
My home does not have any more room on the electrical panel for more circuits, so upgrading the panel would be an additional cost. And there is the cost of adding a dedicated 240 volt outlet for charging a plug-in car. No thanks for now.
You make a lot of good points, Naperlou. Yes, the real hogs are the big vehicles. That's why it's good to see Ford's electric cargo van in there. And, yes, the ratings do leave room for improvement. Right now, the ratings are an exercise in physics and math. Using the EPA's methodology three years ago, Nissan was able to make the claim that its Leaf got 367 mpg and Chevy said the Volt was at 230 mpg. Then the EPA sat down and recalculated it, and the numbers settled in around 100 mpg. What it proves is that mpg ratings of electric cars is still an inexact science. See the link below for more info.
One more thing to add to the equation, g-whiz, is the maintenance adder. Most people have a fairly good ide what it takes to maintain a conventational car and when various short-lived product will fail. However, with the EVs you are dealing with a high-cost battery with an expected life shorter than that of the auto itself. Do you have to buy a new battery? Can you sell the old one at a scrap yard so they can remove / resell the components and metals, or do you have to pay a recycler?
While the EPA's newer method to calculate MPGe for electric cars is a step in the right direction - it is far from merely "inexact", it is in fact quite fraudulent!
I urge anyone that wants to understand the immensity of that fraud to do a thumbnail calculation of how much energy (or fossil fuel...at the power plant) EV's use. You will find that the true MPGe should be approx. today's figure divided by ~2.5. In other words, the LEAF does not use the energy equivalent of 100 MPG, it gets about 40 MPGe if calculated honestly.
Note that this has nothing to do with the efficiency of electric motors, which can be very high. It has everything to do with the real (and necessary, by the laws of physics) inefficiencies of converting fuel (Coal and Natural Gas at power plants) to electricity.
Read the comments written in the link you posted. Sparky has it right.
I drive my all electric 64 miles/day, and the cost of electricity to do that is $2.50 (based upon our local rate and method of generation). The cost/mile is 3.9 cents/mile. Now if I look at the cost for driving that route for the 38,000 miles I have done with my electric, it comes out to a total cost of $1,484 in electricity. The cost for gas (based on an average over the last 2 years of $4.10/gallon) comes out to $7,790 for the same 38,000 miles (20.5 cents/mile). Take this out to 100,000 miles and the cost in electricity is $3,905, and gas is $20,500. I have never spent less than an additional $12,000 to keep any of my last 3 ICE engined cars running for 100,000 miles!
So far with the electric, I have put nothing into the car excedpt tires - - no belts, no hoses, no oil changes, no water pumps, no new mufflers, no new tranny, no leaky radiators, no factory crated engines, etc, etc. After two years of drivng pure electric, I have lost not one single mile of range! I have driven in 108 deg. heat and in 28 deg weather, wet and dry. Never a problem! Yes, the initial investment is high, but I feel that over time, I will make up that additional cost. The batteries are recycleable two ways: they are used in stationary power back-up systems, and they are also re-conditioned or recycled through the company.
The last part of my EV plan is to have the solar panels installed to pay my way before I use any power to re-charge. (Check out Solar City for their plan.) The best thing is that I don't leave a layer of oil on the window of the car behind me (something I have to clean off every day from the ICE cars ahead of me), and I don't have to get screwed everytime someone upstream feels that now is the time to jack up the gas prices again! Just sayin!
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