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Hybrid Cars Don't Live Up to Mileage Claims
Omega1045 writes "Wired News is running a great little article about how hybrid cars (specifically Honda and Toyota models) do not come anywhere close to living up to their fuel efficiency claims. The article highlights that the EPA tests are more to blame than the car manufactures. Consumer reports has shown that the mileage for these cars can be as low as 60% of the claims. The article also links to a blog authored by hybrid enthusiast Pete Blackshaw detailing his failures getting any real answers on why his Honda Civic Hybrid isn't getting better fuel mileage. It looks like these cars are more hype than help in the battle against pollution and foreign fuel reliance."
I didn't see this answered in the article, but are other gasoline-only autos also overrated?
I mean, if the same EPA testing standardis used on all cars, and the hybrids are overrated...
That said, I have an '88 Volvo that I watch the mileage of pretty closely, and I get b/w 25 and 30 mpg. And it's a big heavy bastard...
hmmmmm....
Have quite a bit less power than their gas-only counterparts (like the hybrid Civic). I've seen people trying to drive these things like they're race cars, and that certainly isn't going to help.
MPG estimates are easy to reach when drive like a responsible person, and according to the cars manual. This is often a bit slower than you are comfortable with, hence the problem. It just happens to be that the rift between gas waste with the two driving styles is quite larger with the hybrid engine.
Drive nicely, you're mileage will be a lot better.
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Perhaps the Civic isn't as great as the EPA rated. I don't know, I'm not interested in one. However, Randy Rathbun's blog had a mileage log that contradicts this story at least as far as the Prius (the only hybrid I'm interested in at this point) is concerned. I trust his empirical evidence more than a poorly researched article that paints all hybrids with the Civic-brush.
mbbac
Now for some truth. (disclaimer I drive a hybrid) On the freeway, the hybrid system doesn't do much. It's all plowing wind and the engine never shuts down.
However in city traffic jam traffic, it shines big time. That awful creep and stop at metered on ramps and passing the wreck is usualy done with the engine off most of the time. This is where regular cars are very ineffecient. Unfortunately most of our time on the road isn't in these conditions in the USA. Now as part of the reality check, I have missed the EPA estimates by about 10 MPG. It's still double the milage I got on my last car. At current gas prices, the payback period has droped from never to something in the car's lifetime. If gas goes up more, the payback time will shorten much more. I don't regret my used Prius purchase.
I replaced a 2.3 Liter 4 cyl Ford Mustang with a 1.5 Liter Toyota Prius. Mpg went from 24-28 to 43-48 for my commute. Getting 400 miles on a tank is normal. I haven't risked running out of gas to try for 500 miles, but I've had enough gas left at the next fill to have done it.
The big savings I found for mine is as a standby generator. During an outage, I ran a TV, refrigerator, lots of lights, and chest freezer off the car. The engine did not run all the time. It would start, cycle for a few minutes and shut back down. Overnight my best guess is I used 2 gallons of gas. Most portable generators would require a refill every 3-6 hours to do the same job. At that consumption rate, I would not worry about refilling it for several days of constant running as an emergency generator. That could never be done with a conventional car.
The truth shall set you free!
YMMV is correct. Why it varies is important.
On the highway, a Hybrid engine is just a low-powered gasoline engine -- generally, the electric engine does not engage over highway travel. I say low-powered, and not under-powered, because today's engines have an obscenely high average horsepower. An "economy" car like a Civic or a Focus has a better power to weight ratio than many classic V6s. Your '69 Type 1 put out 55 horsepower, which was plenty to get 4 passengers and their gear up to 75 MPH.
As a low powered gasoline engine, you get your best economy by accelerating slowly and allowing the resistance of the engine to adjust your speed. Braking on the highway, or downshifting before accelerating, will take a huge bite out of your economy.
It's in city driving where the hybrid shines, but again, only if you drive it correctly. The big thing is to try to keep the gas engine shut off as much as possible. This is performed by accelerating slowly from stoplights and braking slowly as well (more energy is recycled by the magnetic brake when less is lost to the "backup" brake). Jackrabbit starts will be tempting, as the electric assist engine has a TON of torque, but resist it! That's the only way you'll see your economy improve.
To be honest, these driving methods will help you improve the economy of any car, especially 3 and 4 cylinder engines, where keeping the revs low and speed constant has a bigger effect than with a 6 or an 8. But the difference in economy is even wider for a hybrid. Whereas I can see an 8 mpg difference between racing to work (27 mpg)and driving casual (35 mpg) in my turbocharged I4, with a hybrid that difference could be close to 20 mpg.
The EPA drivers know how to drive efficiently, and that's why their scores are so high. You can learn to drive like this too...it's why the Insight has a momentary MPG rating right on the dashboard. The guy from AutoWeek who did the long-term Insight test said he considered the average MPG rating to be a "different KIND of performance rating," and that he made it a game to get it above 60.
Hey freaks: now you're ju
I heard (also on NPR) a few weeks ago that most of the pariculate emissions from diesel could be vastly reduced by using low (or zero) sulfur fuel. The EPA would like to have mandated the new fuel by now, but the trucking industry is heavily against it. They're going to mandate it anyway, I think starting in 2007, perhaps rolling from CA eastward.
Hybrids ARE great for city driving, when the maximum power output of the drive line is almost never required. The batteries can happily slog through traffic for quite some time without needing to run the IC engine. However, high speed highway driving, merging, and passing will often require 100% of available drive line power, this is where hybrids fall down.
Running both the engine and the electrics drains the batteries, requiring the engine to continue to run even after 100% power is not required, the engine has to run fairly hard to charge the batteries back up, and of course there is a loss of efficiency in the conversion from mechanical to electric energy. If you drive like grandma, your hybrid *might* reach the claimed highway efficiency, but at the cost of speed, merging and passing.
Just for comparison my 1992 Alfa Romeo 164s has a 220hp fuel-injected 3 litre V6, asside from the BOSCH Motronic 5.1-ML injection, it is a decidedly low-tech engine. Single overhead cams, 12 valves, 60 degree, the valve train and geometry of this engine date from the mid 60s. The 164s weighs 3650 lbs, roughy TWICE what a Honda Insight weighs. The Alfa also features leather interior, kickin' sound system, very good aerodynamics, and a top speed in excess of 155 mph. If I take this beast on long highway drives, I can manage 31 mpg. The reason? Most the time the engine is using only a small fraction of it's possible power output.
When a hybrid, or for that matter, any underpowered vehicle gets out on the highway the conditions often require the drive line to run at maximum output. No mater how lean burning or smart a fuel injection system is, it has to deliver more fuel to produce more power. But if a 3650 lb luxury/sport sedan can get 30+ Mpg why can't an 1800 lb econo car get 60+? The answer is it CAN. And without the added weight, cost and expense of hybrid systems. Hybrids are *a* solution, they are not however in my oppinion the *best* solution.
What we need are high effiency small-ish engines in the 1.2 to 1.8 litre range put into light weight, aerodynamic bodies. The results would be affordable, reasonably fun to drive and just as efficient as hybrids for most American drivers. Those living in cities may want to consider a full electric solution, or *gasp* public transportation (which is, unfortuneately not really up to snuff in most American cities). In addition, a displacement on demand system could improve the efficiency of small cars in city driving as well. Who says only a V8 would bennefit from this technology? A small 4 cyl car could conceivably be set up to idle on only one cylinder at stop lights.
Hybrids may actualy be better suited to high performance applications than high efficiency applications. Witness the Toyota Volta. The Volta is efficient because it rarely uses 100% of it's available power, and since about 50% of that power is provided by electrics, it's IC engine is similar in efficiency to that of a vehicle with 1/2 the total drive-line power of the Volta. The result is a vehicle that rarely taps it's full potential, and operates at maximum efficiency most of the time rather than maximum output.
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Since my work is researching HEV's and I keep pretty well up to date on the tech, I might have a point or two.
HEV's are a passing technology an interim beast which really is already out of date. They never would have existed if the numbers had been balanced. HEV's in battery storage cannot be more than about 10% thermally efficient. That's pretty rotten considering that they must do that downside of the engine efficiency. They do have the advantage of allowing Electricity to charge them up when parked. The energy efficiency issues hit this too.
There is a far better technology coming right away. It is a Fuel Reformer/Fuel Cell combo. It has all of the advantages of storing braking energy etc and none of the difficulties with batteries etc that correspond in scale to the Prius etc.
Military interest in Hybrids is related to dual use of the generator. There is also stealth.
I expect that a civilian buying a hybred thinking they are saving energy or getting a good deal is going to get stuck. The technology just isn't that good. There are exceptions to this. If you are a route driver like a mail currier you will win with a hybrid. If your commute is a lot of stop and go stuff with long periods of stop or very slow driving, it pays off. The more long high speed driving you do, the less value the hybrid is going to have.
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