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Fuel Efficiency Numbers Overstate MPG More For Cars With Small Engines
whoever57 writes: All official numbers for fuel economy in the EU typically overstate the miles-per-gallon figure that drivers can expect to achieve in typical driving. A recent study confirmed this once again. However, what the study also found was that MPG figures are more unrealistic for cars with smaller engines than for cars with larger engines. Actual MPG figures achieved based on typical drives for cars with small engines could be as much as 36% under the official number, while those cars with 3-liter engines would typically achieve 15% less than the official figure.
These discrepancies need to be accounted for if we're going to be serious about regulating fuel efficiency. But then, we should be using gallons-per-mile instead of miles-per-gallon, too.
"But then, we should be using gallons-per-mile instead of miles-per-gallon, too".
No. You should be using litres per kilometer. Especially so when talking about the EU.
If you try to push a small engine to drive like a larger one, you'll be accelerating harder, therefore using more fuel than under normal acceleration.
In similar manner, some years ago, I had a Grand Cherokee that my wife couldn't get more than 11mpg out of, while I could do 17mpg.
We have different driving styles. She is a leadfoot, while I drive like I have an uncooked egg between my foot and the gas pedal.
Perhaps this article might better be titled "Want better gas mileage? Don't drive like a gashole."
The shepherds did so well protecting the flock that the sheep no longer believed that wolves existed.
would it not be better to simplify a volume divided by a length to an area. Gallons/mile is best represented in represented in hectates or furlongs^2.
Some drink at the fountain of knowledge. Others just gargle.
1 US gallon / mile = 0.00364583333 sq inches
Some drink at the fountain of knowledge. Others just gargle.
The study is by Emission Analytics, and here is the original link (as opposed to TFA from The Telegraph).
Note some misleading elements from TFA: they show only the three smaller classes for UK cars, seemingly indicating that small cars are the worst gas guzzlers, whereas cars with higher engine sizes are actually much worse according to the original study (see the graph). So the lesson is: still buy a small car, just not a very small one for best fuel efficiency.
Another interesting bit that is not in TFA is that the data for US cars is different: there, cars between 1 and 3 liters in volume (I assume this is the large majority of the car pool) have less than half the mileage. Also, the smallest US cars are actually the most efficient of any class, even though their efficiency is below UK average.
Victims of 9/11: <3000. Traffic in the US: >30,000/y
(that being the USofA) is to worry about how far we can go on a tank of fuel. This is a throwback to the days when trips of any significant distance could easily leave you stranded between fueling stations (which used to be as much as hundreds of miles apart)
In that case, knowing distance per unit of fuel is more important than fuel per unit of distance.
In Europe, where distances are SIGNIFCANTLY shorter it is much more interesting to worry about the cost of the trip, especially when public transport options are close competitors in price. In this case the unit of fuel per unit of distance makes a much easier comparison.
Now lets try the same using the metric system:
1 litre / kilometre = 1 sq millimetre
That is another win for the metric system in my book.