Hybrid Drivers Provide Real-World Mileage Data 1167
The hot-selling Toyota Prius averages 48 miles per gallon among over 150 cars from across the country, with most drivers achieving between 45 and 51. The V-6 Honda Accord Hybrid delivers 30 miles per gallon while Ford's Escape Hybrid SUV averages 28. All hybrid owners are encouraged to post their data for these and other cars on the Internet's largest hybrid mileage database.
Reliable fuel economy figures are increasingly important as consumers explore their options in an emerging hybrid car market. Hybrids, like the new Lexus RX 400h, pair combustion engines with electric motors that recharge while driving to improve gas efficiency. "Until lately," said GreenHybrid creator Jason Siegel, "consumers have associated hybrid vehicles with a small niche of fuel-conscious environmentalists, but today's hybrids offer the best combination of high performance, great mileage and luxury features of any cars on the market."
MPG science (Score:5, Interesting)
Basically, I floored it when taking off and took the car to the max.
You know what I found, I got 25 MPG in BOTH cases. In fact, I got slightly better milage when I was agreessive. Granted, this was not completely scientific, but it made me wonder about doing more accurate testing. I expected to see a 5-10 MPG difference. To follow up, I drove the last tank at a normal "in-between pace".
I was talking to someone at work about it and they thought that maybe today's engines are tuned so well and change with different environments that it doesn't make a difference. It only makes a difference if you are stopped a lot like in traffic jams.
Anyone in Central Indiana want to join me for some more scientific testing?
But... (Score:4, Interesting)
Re:MPG science (Score:5, Interesting)
Re:But... (Score:2, Interesting)
This technology has really been around for a long time, along with true hybrids which use the gas engine to only drive a generator. I suspect it would have been adopted much earlier if the ar makers had just "done it".
ah well.
In defense of EPA estimates (Score:5, Interesting)
What they do provide is a car-to-car comparison that is consistent regardless of driving style, load, weather or other conditions. When you compare EPA mileage statistics, you're comparing apples to apples.
Hybrids throw a monkeywrench into the mix, so we'll probably see an adjustment to the EPA methodology at some point.
Data accuracy (Score:2, Interesting)
Cruise control helps a lot (Score:3, Interesting)
Re:need independent testing (Score:5, Interesting)
We are getting 50mpg instead of 20mpg, and we no longer have to buy premium gas...we are saving $1200 a year, not counting the lower loan payments for the car we traded in.
I would go on, but I am starting to feel way, way too good about myself
P.S. - I paid under MSRP for my Prius and got it in a week.
Is it just me (Score:3, Interesting)
How can these cars be touted as environmentally friendly when you could easily increase your gas mileage by driving a 4-cylinder instead. That way, you get the gas savings and you aren't throwing away a huge battery full of toxic waste when you're done.
Calling the Ford, Lexus, and Honda Accord "environmentally friendly" hybrids is disingenuous. They aren't helping the gas problem whatsoever.
I don't want luxury (Score:4, Interesting)
Cheap, basic transportation. I'll buy my own seat covers, floor mats, stereo, etc.
I hate the inflated prices car makers charge, getting people to buy on credit what they can't really afford to own. I guess I'm the only one, though.
Re:seems sort of a waste (Score:5, Interesting)
For those who don't know in this case the diesel engine is basically just an electric generator that powers the electric motor. Because as a generator it can run at a constant speed it's even more efficient than a traditional diesel. It works for trains, I'd guess it would work for cars/trucks/SUV as well. GM/Allison has built buses this way that see a 60% MPG increase vs conventional diesel buses. If a Chevy heavy duty pickup sees a similar increase that would put it near 40 mpg on the highway. Pretty good for a 1 ton truck.
Re:need independent testing (Score:3, Interesting)
No flame intended, it's just simple truth.
Here's a quote from a Car and Driver article that summarizes what I was getting at: http://www.caranddriver.com/article.asp?section_id =15&article_id=8427&page_number=1/ [caranddriver.com]
Re:MPG science (Score:3, Interesting)
One thing that does make a difference is how fast you drive on the highway. I know I get much worse mileage driving at 80-90 than I do at 60-70.
I have a couple of empirical observations. These observations were made in a 1998 Subaru Impreza OS, 2.2L 4 cyl. boxer engine, 4-speed automatic, AWD. Some of the observations I have also made with a 1999 Chevy Prizm, 1.8L straight-4, 3-speed automatic, FWD.
Normal driving on my commute, a six mile trip involving about one mile of 65MPH on a freeway, but mostly 30-45MPH, but not many stoplights, I got typically 18MPG in the Subaru, 24-25 in the Chevy.
Driving to Saratoga, to my wife's workplace, a 28 mile trip involving 20 miles of 70MPH on a freeway, typically 22 in the Subaru, 29 in the Chevy.
Cross-state trip to Rochester, about 250 miles, via the New York Thruway (I-90), mostly at about 70MPH, 27MPG in the Subaru. I don't know yet what it is in the Chevy.
Same trip, using U.S. 20 instead of I-90, mostly at 45-55MPH, over beuautiful rolling hills (worth it if you have the time!), 34MPG in the Subaru (surprised the hell out of me!), don't yet know for the Chevy.
So, yes, speed is an element, but also the length of the trip is relevant, because shorter trips are closer to done by the time the engine is warmed up and ready to operate at its best.
BTW, despite this, I don't advocate letting your car sit and warm up (exceptions for very cold winter days) because you end up using more fuel that way than just going.
One other point worth noting is actually a re-labeled Toyota Corrola. As such, it is mostly influenced by Japanese engineering more so than American engineering. That is not a knock against American engineers, but the Japanese engineers never really had an environment involving cheap oil like we have historically had here.... thus they were the ones willing to risk putting hybrids on the market.
1990 Geo Metro MPG = 2005 Prius MPG (Score:3, Interesting)
1990 Geo Metro XFI Specs [consumerguide.com] & Mileage [fueleconomy.gov]
Weight: 1694 lbs
Cargo Volume: 31.4 cu. ft.
Front leg room (Max): 42.5 in.
Rear leg room (Min): 32.6 in.
Crash Test: Driver ***, Passenger ****
City: 53 MPG
Highway: 58 MPG
Combined: 55 MPG
2005 Toyota Prius Specs [consumerguide.com] & Mileage [fueleconomy.gov]
Weight: 2890 lbs
Cargo Volume: 16.1 cu. ft.
Front leg Room (Max): 41.9 in.
Rear leg Room (Min): 38.6 in.
Crash Test: Driver *****, Passenger ****
City: 60 MPG
Highway: 51 MPG
Combined: 55 MPG
Re:MPG science (Score:5, Interesting)
Every time you double your speed, wind resistance quadruples. It goes with the square of the velocity.
However, that's not the whole story by a long shot, which should be obvious. If the slower you go, the better gas mileage you get, you might think you get infinite gas mileage at a standstill. Of course, you don't.
What makes the difference, then? Gears. See, your engine is extremely efficient in an RPM band - around the torque peak (called the power band). It's most efficient at the bottom of that power band. The gears don't actually help anything - as you learn in basic physics, simple machines don't change the amount of work that needs to be done. What they do is allow the engine to run at a more efficient RPM for a given speed.
So what gears do is put peaks in the fuel efficiency curve. Depending on how a car is geared, 55 mph can be very inefficient, because it could be at the worst spot below the power band, which it is on my 93 Mazda. 55 mph gets me 28 mpg, whereas 65 gets me 30, and 70 gets me 34. 75 gets me about 32, and 80 gets me about 30 again (this is all measured).
It's not just as simple as slowing down. You have to know how your car is geared - if it's got an overdrive, it's very possible that going 55 could hurt your gas mileage via engine inefficiency more than it helps via aerodynamics.
That doesn't mean that 34 is the best gas mileage I get, of course. My peak gas mileage is in the mid-40s, in the peak of the previous gear (if I lock it into 3rd via the shift lock), where it's about 36-37 mpg. At lower speeds, aerodynamics losses are well below rolling resistance, so going slower doesn't help.
Re:My 1978 Mini gets over 55 mpg (Score:1, Interesting)
Re:MPG science (Score:3, Interesting)
Old cars were carburated. When floored, lots of extra fuel would get dumped in the carb, and any that didn't get burned in the cylinders just got dumped down the tailpipe (possibly igniting, causing exciting backfire noises). So in the 70's oil crisis, we were all told to accelerate gently.
Modern fuel injection has made that a thing of the past. Engines just do not get fed more fuel than they can burn, so it doesn't matter too much how hard you accelerate.
Re:But... (Score:3, Interesting)
If you figure that a car with half the mileage rating would cost you $5000 less and gas costs $2.00/gallon, you'd end up driving around 100,000 miles before you made up the extra cost.
It's funny when you consider that a Daihatsu Charade [daihatsu.com.au] has a list price of $11,490 AUD or $8900 USD (does Daihatsu sell in the US any more?) and is rated at around 45/mpg with a standard gasoline engine. Make cars lighter and hybrid technology doesn't even matter. A Diahatsu Charade weighs 1587 lbs, Toyota Prius 2890 lbs. You pay 3x as much for a hybrid vehicle to tote 1300 extra lbs around at the same fuel efficiency.
Re:Hybrids long-term costs unknown (Score:1, Interesting)
I wonder what the plan is for all the old batteries? Chances are you will be charged a disposal fee like most states currently do with tires.
The thing that really irks me about new vehicles is the fuel mileage. I remember when the Volkswagon Rabbits came out. The gas version got 35mpg and I had a friend with a diesel model that would get 78-80mpg at 75-85 mph.
I now drive a Dodge RAM pickup that gets 16 city and 16.5 highway. In the past I had a 1981 Chevy 4x4 that after some minor changes got 24 mpg on the highway and did better on emmission tests available at the time. I also currently have an 84 Trans Am that gets 24 city and over 30 highway and it has 169,000 miles on it, and still beats most new cars in emmission tests. You would think that with all the advancements in fuel and ignition technology that they could improve on the old carburator's. The only improvement I have seen is that I don't have to change points anymore (anyone else remember them) and messing with the carburator choke that never seemed to work properly. Oh, and on the 40 yr old cars, obviously you have never worked on one. They are built like tanks. The crumple zones were not needed for protection until about the last 20 years when builders switched to unibody construction. I would much rather be in an old Pontiac Bonneville than in anything rolled out of a plant lately. And talk about the leg room.
Re:Hybrids not the answer (Score:5, Interesting)
Toyota is doing what GM and Ford couldn't do. It's letting it's customers help fund it's R&D related to the transition from gas to electric.
Future cars are going to be all electric. That's all there is too it. Why? Simplicity. It takes a great deal of effort to design a mechanical structure that can transmit anywhere from 200-600 bhp from the front of the car to the back. You lose efficiency on the drive shaft, at the transmission, etc.
The end game of cars is going to be where the motors are built into the wheels. The power plant is interchangeable (and inconsequential). When you brake, all four wheels will capture the energy into some sort of temporary energy storage device.
Toyota knows this. The Prius is subsidized R&D. Personally, I think it's a fabulous idea.
Re:MPG science (Score:2, Interesting)
Then I converted to 3.73 gearing in the rear end. My fuel economy dropped down to about 22 mpg. On the Interstate I was at 2500 RPM@65. I have since converted it to a manual with some mods. I hold a steady 65mph@2K RPMS w/20mpg. If I rev it more than that it just sucks down fuel like no tomorrow.
Part of the reason for this is that 5.0 V8s in mustangs make peak torque at 3K rpms, and its a LOT of torque (300ft lbs, a lot for a car that makes about 100hp less than the torque ft lbs!). So at 2K rpms you are still have plenty of torque. so you aren't lugging the engine. The trouble with the 5.0s is that (in stock configuration) when they are hitting peak torque they are only 1000 RPMS from peak HP so they are really chewing through the fuel. You can actually get even better gas mileage with a 6 speed and a slightly more conservative gearing (I have seen 28-30mpg on relatively stock cars).
And then.... on the other end I have seen twin turboed 5.0s (Stock bottom end) that easily pull low 11s and high 10s making 25mph on the interstate and like 20mph in the city. Expertly tuned, but its not every day you see a 500HP car getting mileage like that!
This rambling, tangental post brought to you by someone who should be doing something more productive.
J
Reliability (Score:4, Interesting)
Toyota gives the batteries a 10 year warranty. The gas engine is the same as the engine in a Corolla, just adjusted to run on a different combustion cycle. There's no gearbox, so that leaves the transaxle and computer to worry about... Personally, I'll take that bet.
That's it!? (Score:2, Interesting)
I get the same mileage as you out of a 17 year old car, with no electric assist.
I was looking at a Honda Civic Hybrid, but it doesn't look like there is any advantage to switching to a hybrid version of my 17 year old car.
Re:I don't want luxury (Score:1, Interesting)
750cc engine, built like a russian tank. By russians. On the fringes of Siberia, so you know it will handle whatever crappy weather you get.
Sidecar (removable) so it will run in ice, snow, mud, whatever. They even have two wheel drive (selectable) models that will go places SUVs are scared of.
Mechanically basic, yes, but also mechanically repairable by any halfway competent shade tree mechanic.
Brand, spanking new with two years (or more, depending on dealer) of warranty, under $10K, including delivery charges in the continental US of A.
Re:seems sort of a waste (Score:3, Interesting)
Another thing we haven't seen quite yet is the turbine hybrid vehicle. We've had turbine powered vehicles in the past, but rather than gearing-down the turbine, I believe that you should be able to gain power from the rotating part in the turbine -- just by itself. I would assume that the unit would maintain it's rotation, and fuel/air ratios. I think capacitors come more into play than just batteries, as other electric-only cars have had.
Granted, I am not an engineer, but I've been inspired by things like this [aardvark.co.nz].
and I'm betting .... (Score:1, Interesting)
Re:higher speed = lower accident rate (Score:5, Interesting)
Due to structural crush zones in cars, additional airbags, antilock braking systems, door beams, and other safety features in even cheap cars, accidents are much more survivable than they were even 20 years ago. However, with the trend in this country towards gigantic SUVs for every soccer mom, it may be equally counterbalanced.
The US DOT would have you believe that slower is safer, which it may be in densely populated urban areas. However, in mind-numbing interstate travel (I just made a 742 mile trip last Tuesday and again on last Saturday), you want to go as fast as your car feels safe traveling. This does increase your attention and focus, because you are forced to react to changing terrain more frequently and you realize the margin of error shrinks at higher speeds. I.e. you achieve a slightly higher 'pucker factor'.
There is a limit as to how fast you can safely travel which is mainly governed by how quickly you can stop. Sport Compact Car magazine recently reviewed a race-ready Mitsubishi Evolution 8 with upgraded everything including a beefed up braking system. The stopping distance from 60-0 was an unheard of 98 feet. From 70-0 it increased slightly to 135 feet. Now, from 80-0 we see a shocking increase to 179 feet. 20 mph, 33% faster and you effectively double your braking distance! Keep in mind this is on an exceptional car, real world, average cars come nowhere close to these numbers. Stopping from 60mph in 98 feet would sling the snot out of most people's noses.
Perhaps you're right about 20% faster speed nearly doubling kinetic energy, as that's what the braking system is being forced to deal with and would definitely cause those numbers to nearly double.
Plan for a cheap commuter : Learn to repair cars (Score:4, Interesting)
Hybrid benefits are overrated because of the weight of the vehicles. This decreases much of the benefit.
Take a 1992 honda civic chassis. Look for one of the efficient models (Vx, others). You want a 5spd. They are very easy to work on, and very common. Engine reliabilty is great.
These cars were commonly available with no power steering, and no AC. Power locks and windows? Ha!
Strip the car bare. Gut it. Install some lightweight racing seats. You just saved a lot of weight. And gained a lot of cargo room!
Have the engine reworked. Lots of manuals for this; it can be done in a weekend, with a weekend of preparation. You'll need to clean all the fuel filters, injectors, and install all new ignition components.
Install a wideband o2 sensor with a car monitor. Consider an EGT meter as well. This will let you track your mixture inside the car to see if you're running rich and/or overheating your exhaust valves.
Install a VAFC, a small computer that tweaks the fuel settings. Most of the time these are used for power, but you're going to use it to dial out as much gas as you can without running too lean.
Voila. Plus it's cheap to insure.
Re:MPG science (Score:2, Interesting)
You actually want the rpm that will provide the greatest efficiency for the hp that you need to use to maintain your speed.
My 285hp Z has it's torque peak somewhere north of 4000 rpm. It gets it's best mileage down around 2000 rpm.
This is because it doesn't take 285 hp to keep it steady at 75mph on the highway. Instead, it probably takes 100hp. And the engine can easily deliver that at part throttle at low rpms.
The torque curve usually given is at wide open throttle, and driving at the torque peak would be correct for maximum efficiency of driving at wot. But you rarely NEED to do that.
Re:1990 Geo Metro MPG = 2005 Prius MPG (Score:2, Interesting)
Yes, a Metro is a good vehicle for people who just want to commute on the highway, that's what it was made for. But if you want a real family car, the Prius is mcuh better.
Hell, you could compare the Prius to a Volkswagen New Beetle/Golf/Jetta TDI, or some really old '40s-era Toyotas. It's easy to get 50 mpg, by sacrificing a lot. The point of the Prius is that it was designed to be a no-sacrifices environmentally-friendly car.
Re:higher speed = lower accident rate (Score:3, Interesting)
The army started issuing kevlar helments. The number of injured in the hospital went up.
(jump to the wrong conclusion here)
The soldiers survived attacks and went to the hospital instead of the morgue.
Re:But... (Score:4, Interesting)
The Charade is a tiny 2-door car with no power and a manual transmission. The Prius is a decently peppy 4-door midsize with an automatic (well, continuously variable) transmission.
If you want to compare hybrids to nonhybrids, compare similar vehicles. The Insight averages 63mpg, 40% better than the Charade - and that includes both the automatic and standard Insights (the standard Insight does even better).
Re:One of the most useful things about the Prius.. (Score:2, Interesting)
Miles per 100 Calories... (Score:2, Interesting)
Bicycling in the US is seeing a huge explosion in the number of riders, which is a great thing because as more people turn to cycling as an alternative to burning gas, we are solving not only the gas "crisis" but also helping with our obesity problem and consequently part of the public healthcare problem.
Actually, it's not so simple (Score:5, Interesting)
Which doesn't just limit your range in an all-electric car, but also makes the whole car heavier. It means you actually need more energy to move at the same speed and over the same distance.
Hybrids acknowledge that reality. The electricity in a hybrid ultimately comes from gasoline too, and is only used so often.
I.e., expect to see hybrids instead of all-electric cars for a long time.
2. The whole "waah, but oil is going to end" premise is bogus anyway.
Yes, fossil reserves will eventually end. But here's the fun part: we already know how to produce synthetic oil. We've known it for a long time. And not just theoretically: Germany's WW2 tank warfare was _based_ on synthetised fuel. It wasn't cheap, but it did keep the panzers rolling nevertheless.
That's really the only thing that keeps us using fossil fuels right now: it's cheaper than making synthetic fuel. If fossil reserves start running low, whoppee, we'll just start making synthetic fuel. And all those gasoline or diesel cars will keep running just the same.
In fact, doing that is probably a more economical and viable way to store energy than a ton of batteries in a car.
s/People/Americans/g (Score:3, Interesting)
Re:Stopping distance is another big lie. (Score:3, Interesting)
This is true unless the car in front of you hits a stationary object (e.g. some wall) and slows down extremely fast.
You (as a driver) just have to hope stuff like that rarely happens and the risk*impact is worth it, otherwise you'd leave a much greater gap between the cars.
That said apparently some cars have very good occupant survivability for typical 60 mph crashes.
There's such a thing as too slow (Score:3, Interesting)
I don't know the exact values for the best limit, but here's what I think people should consider:
1) Humans have limited lifespans.
2) Most keep a 24 hour cycle, with approx 16 hours awake. And spend maybe 1.5-2 hours of that on other self-maintenance (and other overheads) - grooming, cleaning, eating etc.
Now if you set a speed limit too low, you'd end up with humans spending lots of time travelling from A to B, and typically back from B to A.
If a commute is 1 hour from A to B and 1 hour back, that's two hours. And that's about 12% of your waking life gone. If by setting a stupid speed limit you increase the commute to 4 hours, that's 12.5% _more_ of your waking life gone.
That's like reducing the average life expectancy of everyone by about 10 years more.
Remember you are doing this for practically ALL the drivers - if just one driver slows down significantly, almost all drivers have to slow down.
That is a LOT of man-years gone
While driving fast kills the unlucky and the careless/ignorant/stupid, driving way too slow kills the unlucky, the careless/ignorant/stupid (by effectively creating a road obstruction/obstacle) AND also reduces the effective lifespan of almost everyone else on the same road.
I'm not saying we should all drive fast (set it too fast and some crash and everyone ends up moving really slowly). But I'm saying there really is such a thing as too slow. Most people have other things they want to do with their lives than spending it on the same road everyday.
Feel free to disagree - maybe most people would/do enjoy driving at a very slow pace to and fro work every working day.