Okay, if any of you are on Twitter getting automotive feeds, there has been a lot of hype and chatter going around since GM announced that their Volt will get an estimated 360 MPG. Not to be outdone, Nissan jumped on the bandwagon soon after announcing that their Leaf will get 367 MPG and will actually be more affordable to the average consumer! But how are they getting these numbers? Remember, MPG is “Miles Per Gallon.” The Leaf is all electric, so a gallon of what?
Not that these advances aren’t great and we’re moving in the right direction to try and become more fuel efficient but there still are many factors to take into account, and the testing to come up with real world results hasn’t really been designed yet. Feedback concerns I hear within my circles are the costs of the electric batteries to replace. I’m sure Mom feeling she made the wise investment, that she is getting great mileage, and protecting the environment, won’t be happy when she one day takes in her electric hybrid or pure electric car to her local Dealer when it just isn’t “holding a charge” anymore and gets told she needs to buy new batteries for $6000 or whatever the going rate will be. And let’s not forget the the battery disposal fee added to that. I don’t think anything is really setup to handle this yet, but it will need to be.
But back to the MPG estimates. There is some revamping of the tests to come out with actual miles being done, but many are still relying on the current tests for gasoline or diesel powered engines. And even this isn’t really accurate, since it isn’t necessarily measuring how far you drive, but rather reads what your emissions are and giving an estimate based on that output. Here is the testing taken from the EPA’s Website:
How are Vehicles Tested?
Vehicles are driven over identical driving patterns by professional drivers in controlled laboratory conditions on a dynamometer, which is like a treadmill for cars. The conditions that occur during driving, such as wind drag and inertia are accounted for on the dynamometer. There are two types of tests that are conducted: city and highway tests.
The city test is approximately 11 miles long and simulates a stop and go trip with an average speed of about 20 miles per hour (mph). The trip lasts 31 minutes and has 23 stops. About 18 percent of the time is spent idling (as in waiting for traffic lights). A short freeway driving segment is included in the test. The engine is initially started after being parked overnight.
The highway simulates a 10 mile trip with an average speed of 48 mph. The vehicle is started “hot” and there is very little idling and no stops.
How Are the Label Estimates Calculated?
Fuel economy estimates are calculated from the emissions generated during the tests using a carbon balance equation. We know how much carbon is in the fuel, so by precisely measuring the carbon compounds expelled in the exhaust we can calculate the fuel economy.
After the vehicles have been tested, the results are adjusted downward to account for conditions that occur on the road that can affect fuel economy which don’t occur during laboratory testing, such as cold temperature, aggressive driving, excessive use of power-hungry accessories, among others. The city is adjusted downward by 10 percent, and the highway by 22 percent.
The equation for calculating the city or highway average fuel economy, given in miles per gallon (mpg), is:FEave = (total sales / [(sales1/FE1)+ (sales2/FE2) + ...+ (salesn/FEn)]
The calculation for combined fuel economy weights the city at 55 percent and the highway at 45 percent using the following equation:
FEcomb = 1 / (( .55 / city FE) + (.45 / hwy FE))
This makes me wonder a little about the HHO Systems I’m working with and know others developing technology for. Since these systems when tuned correctly can virtually get rid of emissions in a standard combustion engine, rather than simply using a Scangauge or writing down the miles and using a calculator based on each fill up, if we applied the above standard, what sort of MPG results could these systems then claim?
And here’s another company getting into the hybrid market I doubt anyone would have ever considered: Lamborghini. Yes, the legendary supercar company is now planning on releasing their own Hybrid Gallardo by 2015 yet still have a V10 or V12 engine onboard. My thoughts are still in the air about this one, but I suppose if the popularity of Tesla (electric hybrid) and the Scorpion (hydrogen hybrid) grow, it might be a wise choice to stay competitive.
