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Japanese Mileage Maniacs
WY writes "Bloomberg reports on the quirky world of Japanese hybrid car hackers: 'Toyota Motor Corp. says its Prius gasoline-electric hybrid car gets about 55 miles to the gallon, making it one of the most fuel-efficient cars on the road. That's not good enough for Takashi Toya.' He managed to reach as high as 115 MPG. He is one of about 100 nenpimania, Japanese for mileage maniacs."
We have people who do the same thing here.. see http://en.wikipedia.org/wiki/Hypermiling
Well, on the way up, the fuel efficiency drops. But you build up potential energy, so you hardly use any energy when the car goes down. Any braking power is passed to the batteries. Driving with my dad's petrol car in mountainous regions in France and Italy, I was always surprised that I managed to get a mileage better than regular (probably helped by the fact that the average speed was lower). The first rule of fuel efficiency is: BREAKING IS FOR LOSERS. If you have to brake, you're not good at anticipating very well. Cross-road or round-about coming up: lift you foot from the peddle. Second rule: KEEP ROLLING. You must make sure you keep on roling. If a traffic light is coming up, I may brake well before the traffic light, then roll along. In all likelihood, the light is green when I reach it, and I may have left a speed of 15 miles per hour. If I had stopped, I would have been slower too, because I'd have to start from zero. It is one of those things people fail to understand (just like: the fastest way to overtake another car is to keep a distance from him (much safer too), instead of tailgating. You can see the opportunity for taking over earlier, you can start making speed, if it doesn't work you break, if it does work you're having a first speed difference in comparison to a tail gater). Lastly, I may drive behind a truck (we have laws here that forbid them to pollute too much so it is OK). Saves up to 10% (more if I were closer, but as long as we don't have a connection between braking and distance control, that is out).
Bert
It's also a two-door compact car. The Prius is considerably larger - perhaps you should be comparing the VW Polo to the Honda Insight, which gets 65-70mpg.
Your Citroën AX is a 650kg 2-door supermini that would be a deathtrap in a collision with anything of any size. Why the hell you would compare it to a 1400kg Prius (which is a 4-door "large family car") is completely beyond me.
You said two things there - 50bhp and diesel. Diesel contains 15% more energy per gallon than gasoline, making any "MPG" comparisons entirely pointless from a carbon-emission standpoint.
Moreover, you also said 50bhp. That's redicolously underpowerd, even for your 650kg Citroën. Forget about having an automatic transmission on a vehicle like that, and you'd better be easy on the clutch or you're going to be in stall city.
Ah, more hybrid misnomers. If you don't understand the battery technologies involved (Ni-Mh in current models), don't comment. Ni-Mh is not "environmentally-disasterous" - in fact, the Ni in the battery is so valuable that Toyota pays a $500 per pack bounty for recycling.
As for the "overcomplicated drive train", the Prius transmission has 12 moving parts, not one of which is a friction or wear component. In the past 5 years, I have never read a single account of a Prius transmission failing mechanically. The same cannot be said for manual or automatic transmissions, which fail all the time because they incorporate wear components (clutches/clutchpacks, syncromeshes, etc) and (in the case of an automatic transmission), high-pressure hydraulics.
This is the typical European Slashdot hybrid idiot post. I've seen it far, far too many times. The post points out how a much smaller, much less powerful diesel-powered vehicle can achieive results similar to a hybrid. Then they top it off with some nice myths about how hybrids are complicated (they aren't - Toyota's Prius is in fact mechanically simpler and far more reliable than a conventional vehicle), bad for the environment (somehow, 80% fewer smog-forming emissions and excellent fuel economy are "bad" because you have to recycle a battery 15 years down the road), or dangerous.
Here's a hint: don't compare a 3000lb 4-door large family vehicle (mid-size in the US) to a 2-door diesel subcompact. It makes you look stupid.
The first rule of fuel efficiency is: BRAKING IS FOR LOSERS.
Absolutely, and that's still important in vehicles with regenerative braking.
The Prius has a bar graph of your MPG per five minute interval. It overlays cute little green car icons to show how much energy you recaptured through braking during that interval as well. But you shouldn't think of those car icons as part of your score. They're more like the bonus you get when the ball drains out of the pinball machine.
Consider this: when you step on the brakes in a Prius, you convert kinetic energy to electrical energy, which is then stored in a battery, which you then use to regain kinetic energy.
But oddly enough, the most efficient way to store kinetic energy is as....kinetic energy. Regenerative braking is a consolation prize for when you had to step on the brakes. Better not to do that in the first place, if you can manage it while being safe and courteous.
And yes gasoline is so cheap for the most part that we can and do by bigger cars that do poor mpg. They sell gas at 25-30p a liter and 9p of that is road tax, so we don't have the extra payments like you do. At that price it just doesn't make much of a dent in the pocket book even when you have to commute more than 30 miles each direction everyday. The other thing we have is wide roads, lot's of parking, and big garages (you can actually get a full sized SUV into most and have the people on both sides of the vehicle and be able to get out fairly easy). The newer houses typically have room for 3 vehicles and easily fit 2 SUVs and a car. (Just to give you an idea of what I'm talking about, a Landrover Defender 110 station wagon is what I mean by an SUV.) Those things seems to have a bigger damper on large vehicle sales here in the UK than the price of gas. I cannot get my "tiny", a behemoth by British standards, regular cab Toyota Tacoma (like a hi-lux but bigger) through the door of my garage, and have to park it in the street. Of course as you know most houses in town don't even have garages. People in the states regularly drive pick-up trucks large enough to haul around the typical British car in the back and rarely ever have a problem finding an easy spot to park in.
Hope that puts things in perspective for you. Of course my dreams of buying a new Tacoma or an FJ cruiser, both larger than I have now, are on the back burner, so I have been eye-balling one of the new Mini's. (The sad thing is it won't fit in my garage either.) It get's a respectable 35-40 mpg better than the 20 I get with the Tacoma. Of course the one I want is the S model rather the eco model. :)
Some people have converted the Prius to a plug-in hybrid vehicle (PHEV) and there's at least one company doing the conversions commercially. It does not become 100% electric, but it does allow you to plug into a wall socket and charge up the battery, then drive some distance (maybe 40 miles) on the battery power before the gasoline engine ever fires up. If you don't drive more than 40 miles in a day -- which would cover most days for me -- then you don't use gasoline. Yet, if you need to take a long trip, you can do that too.
:)
Toyota have announced they want to build a PHEV, but they haven't said when or shown any more information about it. General Motors have shown the Chevy Volt "concept car" which is a PHEV, and they want to put it into production by about 2010-2012 depending on how batteries develop.
The winners in fuel efficiency are always the pure battery-electric vehicles like the Tesla Roadster; it's rated 135 MPG equivalent efficiency on the EPA highway cycle, no funky "hypermiling" techniques required. First deliveries to customers scheduled for late this year.