Over in the UK they tested green cars and the one with the phoniest mileage claim was the Prius. Tests based more on real world driving.

"The worst performer is the hybrid petrol-electric Toyota Prius, which does only 52 miles per gallon, nearly 14mpg below Toyota’s claim."

http://www.timesonline.co.uk/article...298467,00.html

Hmm, those numbers seem high. They must be imperial gallons

 

What a crackup! So mileage estimates over in Europe are off, just like with the EPA numbers here in the US. I guess it's pretty much a universal malady...

 

Consumer Reports claimed 36mpg in their testing for the Honda Civic Hybrid. I have still no idea how they managed to do that, they must have very heavy feet.

 

I'm sure that more people would be lned up to buy the HCH2 if it weren't for the Consumer Reports mpg findings and the resulting pay back for the hybrid "premium". For me, the hybrid premium will be paid back once I get my federal credit (that, plus the tax break on the purchase of my vehicle in NY state.) Who gets a combined 36 mpg that doesn't have a lead foot or drives 85 on the interstate? I'm pretty sure that they must have done their test drives in very cold weather with underinflated tires.

 

Seems totally realistic to me. I drive mine like a normal(gutless) car and don't quite get that A lot of my driving is just around town.

 

CR's city loop must be pretty rugged.Lots of full stops, and maybe a few shutdowns(letting the motor cool).I can't get a detailed description of their look at the web site, but I read the description years ago.
CR-HCH II City 26 mpg Hy 47mpg
Prius 35mpg 50 mpg.
Cr's #s for the Prius are also very low.However, if you compare them to a Corolla(20 city) or a normal Civic auto(18) then their results are probably valid and consistent( roughly 2X the city mpg of those cars).The biggest "fly in the ointment" I've noticed with CR's numbers is the current Civic auto's 18 mpg city-the last model got 22mpg(current model 43 hy vs 40 hy last model).I did find that odd.They do use a mpg correction for temp, but I suspect it is very minor, and doesn't really make up for the extra minutes spent with the ICE on in cold weather.
I can get CR type numbers-Prius- on very short trips-say 2 miles or less- if I drive with no concern for mpg.Our mpg over 3000 miles is about 42-43 with my son doing the majority of miles.He drives with no concern for MPG.Thanks.Charlie

 

IMO, this is a totally pointless exercise, let the media write what it wishes, we know the truth! My Accord 3L v6 (which I traded ) used more than twice as much gas as my HCHII does.This means that I have halved the cost of fuel! My concern is day to day running costs - these are now much improved. Luckily, I could afford the extra capital cost, without a problem, to buy this fascinating and quite excellent small luxury car. BTW my company reimburses me for my mileage costs on the same scale as before ! They have no different rate for hybrids.

 

For the HCHII, one less serious magazine over here reported 6.6 L/100 km (36 mpg US), another (very serious) actually drove the car 5000 km and reported an avarage of 5.8 (40.8 mpg US).

Maybe they exagerate, but the point they are making is valid, i.e. that hybrids consume relatively more compared to EPA or EU figures, than do non-hybrids. In the example above, a HCHII takes (5.8/4.6) 26% more than the EU figure. A typical non-hybrid would consume about 10% above EU/EPA, if driven normally. Sure, it depends on a lot of factors, but still. It goes with my own experience as well, that I find it very hard to get the EU figure (4.6) in the HCHII, but getting the EU figure or lower in a non-hybrid is easy, especially on longer trips. Potential buyers should be made aware of this fact.

 

Few articles I have seen actually explain why this is. One of the biggest ways that hybrid vehicles save fuel is that they use a slightly downsized engine that generates less pumping loss when cruising, and rely on the motors to gain extra power. They are more sensitive to changes in load than vehicles with oversized engines however. Climbing a steep hill at speed with accesories (headlights, etc) running may require far more power than the smaller engine can deliver efficiently.

Running the air conditioner on the same setting will require the same amount of energy on a Civic as a Civic Hybrid. On the hybrid however, that amount of power will represent a greater percentage of the total engine power, and a greater percentage of the total fuel consumption, however, the absolute difference in consumption should be roughly the same*.

Another factor has to do with sudden braking. How rapidly one brakes will make no difference in MPG on a non-hybrid car, as all of the energy is converted to heat one way or another. Hybrids however can regenerate up to a point, then use friction brakes after that. Braking suddenly, or with more force than the regenerative motor can handle will also reduce hybrid MPG relative to EPA, which implements gradual braking and thus allows more charging. This is often unavoidable though in the real world, such as braking to a stop down a hill. I would not be surprised if the CR loop implements several panic stops, which would disproportionately hurt hybrid mileage.

* The exception would be if the extra load forces the hybrid engine to run above of its efficient RPM range, and thus use more fuel even in an absolute sense, which may well be the case running AC on a hill climb

 

I too wonder. I find one important factor - the weighting betweeen "urban" and "extra-urban" driving in the "combined" milage, and the fact that hybrids get an urban figure which is close to the extra-urban. ("Urban" and "extra-urban" are the EU words meaning about the same thing as city and highway. But not exactly, the test procedure differs somewhat.)

A typical non-hybrid (Accord Sedan 2.0 MT) have consumption figures of 10.9/6.3/8.0 L/100km (urban/extra-urban/combined). With a bit of slow highway and careful suburban driving, it's relatively easy to get below the specified "combined". But, the figures for the HCHII are 5.2/4.3/4.6. It then becomes really difficult to beat the combined milage, even with slow and careful driving in the countryside. (Yeah, I know you folks on this site can do it, with 52 psi in the tires, no AC, no headlights, shutting down the engine when going downhill, and driving 42 mph on the highway.)

I think the Prius gets better "urban" than "extra-urban" milage, which makes it even more difficult.

Most people look at the specified combined milage only, when buying a car.

There are certainly more factors. Sure, the hybrid is relatively (i.e. in percent) more sensitive to external factors such as wind, rain, surface etc. And the tests for the official figures are done in nearly ideal conditions. In fact, they are done on a rolling road, indoors.