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Hybrid Drivers Provide Real-World Mileage Data

Jason Siegel writes "Hybrid cars seem like the answer to rising gas prices, increased pollution and growing dependence on foreign oil, yet EPA tests have failed to produce reliable mileage estimations for consumers. Dependable fuel economy figures are now available at GreenHybrid.com, where hybrid owners have logged over 5,000,000 miles of driving information in real-world conditions. Unlike government tests and individual accounts, the database analyzes thousands of actual experiences to provide true mileage statistics." Read on for the rest.

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."

19 of 1,167 comments (clear)

  1. MPG science by suso · · Score: 5, Interesting
    You know, I'm starting to wonder if some of those gas saving tips like "start and stop slowly" have been backed up with real world testing. I just spent the last three weeks testing the hypothesis that "driving smoothly" (ie, starting up slowly and anticipating stoplights, etc. saves a lot of gas. Here was my test. By the way, I have a 2004 Honda CR-V that gets a rated 24 MPG Highway:

    • Fill up tank with gas (til the auto stop turns off)
    • Drive smoothly for the whole tank (tried to never let RPMs go above 2500)
    • At end of tank, calculate gallons to fill back up and miles traveled
    • Drive through another tank of gas, but this time very agreessively.
      Basically, I floored it when taking off and took the car to the max.
    • Make same MPG calculation at end of tank.


    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?
    1. Re:MPG science by avalys · · Score: 5, 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.

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    2. Re:MPG science by Hadlock · · Score: 5, Informative

      Which is exactly why the speed limit when from 70 to 55 durring the oil crisis. Someone will correct me, but wind resistance is cubed every time you double your speed. Our old '84 caddilac with trip computer got 25mpg at 64mph, but got 17-19mpg at 70mph. Closer to 28mpg at 55mph.

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      moox. for a new generation.
    3. Re:MPG science by cornjchob · · Score: 5, Informative

      I know I get much worse mileage driving at 80-90 than I do at 60-70.

      That's because most transmissions in production cars have their highest geared tuned so that the engine's in its RPM sweet-spot around 60-70mph; after that, the amount of gas per RPM starts to increase considerably more.

      I'm curious as to just how high the grandparent kept his RPMs when he got similiar gas mileage driving timidly and agressively. Also, where has anyone heard stopping slowly increases mileage? Maybe in a car with regenerative breaking, but certainly not in a good ol' ICE powered car. If your foot's not on the gas, only idle gas is going to the engine (unless the computer is doing something, but it shouldn't affect that much). Unless I'm missing something, I can't see how slowing down gradually will increase anything beside the frustration of the driver behind you because you're not getting to a stop light quicker :-P

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      We now have confirmed reports from an informed Orange County minister that Ethel is still an active communist.
    4. Re:MPG science by Everleet · · Score: 5, Funny
      YMMV

      Nice.

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      It's tragic. Laugh.
    5. Re:MPG science by barawn · · Score: 5, Interesting

      Which is exactly why the speed limit when from 70 to 55 durring the oil crisis. Someone will correct me, but wind resistance is cubed every time you double your speed. Our old '84 caddilac with trip computer got 25mpg at 64mph, but got 17-19mpg at 70mph. Closer to 28mpg at 55mph.

      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.

    6. Re:MPG science by aardvarkjoe · · Score: 5, Informative
      You said:
      It takes more energy to accelerate quicker than it does to accelerate slower.
      As a blanket statement, this is false. Going from zero to sixty in ten seconds may end up requiring more work than doing the same in twenty seconds. However, depending on the engine, the gears, the wheels, the road, and all sorts of other factors, it may not. It's a complex problem that can't be solved via simple analysis.
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      How can we continue to believe in a just universe and freedom to eat crackers if we have no ale?
    7. Re:MPG science by sumdumass · · Score: 5, Informative

      I'm glad to notice you are considering wind resistance as well as the difference in stopm and go trafic verses continuous highway driving. The bigest factor in speed verses fuel usage would be resistance.

      Wind resistance, starting to move resistance, going up hills resistance, and the difference the weight has on thse resistance play a crucial role in gas miliage. I have a van and with it fully loaded with camping and hunting gear i average around 1 or 2 miles per gallong less. A slight breeze will drop my miliage another 1 or so miles per gallon on the same 200 mile trip. If it is realy windy, i can expect a little more drop. Newer stream lined cars wouldn't see as dramitc effect as i do on the wind but might see more of an effect on the weight because thier engines typicaly are smaller. Going up some hills, I tend to pull away from other trafic even when pulling a boat or 4 wheelers. I can also get better miliage in town when my tanks are half full (less then 20 gallons compared to 45 gallons total full) with the same cargo. My overdrive in town causes me to use more gass too. I think it is because the high gearing requires more fuel to maintain the same power ratio to the ground.

      On the same note, While in fith gear, if you are having to depress the excelorator more to maintain your speed then you would in fourth gear, you might actualy use more gass then if you increased the RPMS and ran at a lower gearing.

      When i drove a class 8 tractor trailor the manufacturers of the engines (detroit deisel) gave us training on fuel econemy. Some basic bullet points were that the engines have a peak power to torque ratio were when the rpm making the most power croses the rpms making the most torque resulted in the best fuel econemy. The transmisions and rearends were geared with this in mind alng with the rated top speed. Granted with a deisel engine the RPMs were alot lower and basicaly limited to around 2200 - 2300. We usualy shifted and attempted to keep them around 1700-1800 rpms.

      Without idle time (as you mentioned earlier) I could average about 8-9 miles per gallon running at gross (79-80,000 lb). This was up from 4.5 to 5 miles per gallon before we had our little talk. That was acording to the little engine computer read out on the dash. Durring real windy times i actualy get better miliage at slower speed but could run 70 - 80 mph most the time were the speed limit allwed. On a calm day the lower speed would be less then 1 half a mile per gallon because of the gearing. If you could place your car on a dino and check the torque and power rats, you might find an ideal range to drive long trips and realize a big fuel savings.

      Another point was the electronic cruise control. Running with the cruise control allowed engines computer to caculate the exact amount of fuel needed to maintain speed were driving by foot would cause speed to fluctuate enough that the driver would over compensate the throttle and apply too much power to maintain speed. My buick's cruise control saves fuel on long trips much the same but my van's cruise is too old to have much difference (rebuilt and pumped '84 chevy 350). My semi truck would see around .5 to 1 mpg more fuels econemy then without using it. One mpg doesn't seem like much but it adds up. Especialy if you are getting lower mpg.

  2. Accord hybrid by damiam · · Score: 5, Informative

    Before anyone gets confused, I just want to point out that the Accord hybrid is not supposed to be super-efficient like the Prius. It's the top-of-the-line Accord, and the hybrid power is mostly used to increase performance while retaining similar fuel economy to the slower models. It's quite zippy; IIRC it has better 0-60 times than a V6 Mustang.

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  3. My 1978 Mini gets over 55 mpg by sirket · · Score: 5, Insightful

    I have a 1978 British Mini (the old ones) and the gas mileage is anywhere between 50 and 60 mpg. Here we are almost 30 years later and we are getting- lower gas mileage?

    Granted the Mini does not weigh anything and lacks AC- still. The 1 liter engine kicking out 55HP (in my slightly modified engine) is more than adequate to move such a light vehicle. Add to that a suprisingly roomy interior (it will seat 4 people comfortably despite being only 10 feet long) and a car that will corner like a go kart and you have to ask yourself what the auto industry is thinking. Not to mention being able to park _anywhere_ :)

    We have materials today that Alec Issigonis (the guy who created the Mini back in the 50's) could only dream of- lighter, stronger and easier to shape- and yet cars today are far heavier. We get worse gas mileage- sure the cars are more powerful but then again they have to be. I realize some of this weight is the result of safety improvements and the like but it just feels like there has to be a middle ground.

    -sirket

    1. Re:My 1978 Mini gets over 55 mpg by NineNine · · Score: 5, Insightful

      The answer is simple: Americans like Big and Cheap. Look at any city in the US. Every town is full of the same giant strip malls *full* of Big Box Stores, filled with fat people eating giant portions of fast food from their gas guzzling, crappy Ford Explorers. I'm American. Sadly, it's true. Almost the whole country is now like this.

  4. GreenHybrid Server by Anonymous Coward · · Score: 5, Informative

    Really sorry, guys. Slashdot sent me so many referrals the whole server went down! I won't be able to get ahold of my host for 2 hours, so please sit tight. Very sorry.

    Jason Siegel
    GreenHybrid.com

  5. Re:seems sort of a waste by Leibel · · Score: 5, Informative

    Quite agree. The Peugeot turbo diesel option (same Bosch direct injection technology) keeps setting world records. Their 307 just got 3.49 litres per 100km's (or 81.16 mpg in old money) according to this website. They averaged 1,700 Km per 60 litre tank! Why add all the complication of hybrid technology, or why not couple an engine like this with hybrid technology?

  6. Re:need independent testing by pycnanthemum · · Score: 5, Interesting

    Putting the flaming comment about people lying to make themselves feel better aside, the ROI for a Prius is decent. A Prius starts at about $20K so if someone "downgrades" from a larger, lower mpg car like say, a Nissan Maxima SE, s/he could feasibly save a lot of money.

    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.

    P.S. - I paid under MSRP for my Prius and got it in a week.

  7. higher speed = lower accident rate by coyote-san · · Score: 5, Insightful

    Mass carnage was predicted when the double nickle speed limit was dropped. In fact the accident rate WENT DOWN.

    There were several reasons for this. N.B., all of these were predicted by the proponents for the change, but dismissed by the safety "experts."

    First, anyone with a clue knows that the biggest threat on the highway is traffic traveling at different speeds, not the absolute speed. People tend to stay in their own lanes - and can even comfortably stay in the right hand lane - if everyone is travelling at about the same speed. But if there's a 20 mph range (which was common in the interurban areas of the square states) there will be a lot of lane changes even when traffic is relatively light. At those speeds just tapping a car may be enough to cause the driver to lose control.

    Second, a realistic speed limit actually lowered the speed of the fastest drivers. A driver going 20 mph over the posted speed limit doesn't have much motivation to avoid going 30 mph over the posted speed limit. But the same driver at the same original speed, if it's the speed limit, will often stay at that speed.

    Finally, these roads were designed for traffic going at ~70 mph. At those speeds the road has just enough variability to keep the driver's attention. At the slower speeds the roads are mindnumbingly boring and the driver's attention tends to wander. You wouldn't think it would make that much of a difference, but I've driven between Denver and Seattle at both 55 and 75 and there is absolutely no comparison. (I-80 thru Wyoming and the Columbia River Gorge still suck because they were long, straight flat segments.)

    That's why the death rate went down when the speed limits were raised. The annual death rate is climbing again, but that reflects more passenger-miles.

    P.S., the Colorado Dept of Transportation will actually adjust the speed limit to match the drivers, not the other way around. They feel, reasonably, that thousands of drivers will make an informed decision about the best speed for a segment of road. Sometimes their hands are tied because of regulations, but I've seen them change the speed limit on other segments.

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    For every complex problem there is an answer that is clear, simple, and wrong. -- H L Mencken
    1. Re:higher speed = lower accident rate by Dashing+Leech · · Score: 5, Insightful
      "In fact the accident rate WENT DOWN." "That's why the death rate went down when the speed limits were raised."

      Not that I disagree at all, but there is a common assumption or mis-conception that you seem to be repeating here, unless you have a separate source. A lower accident rate does not mean a lower death rate or vice versa. It might be true in this case, I'm not sure.

      The argument about relative speeds being the problem probably has a lot of truth in it; I've read research in this area and it certainly seems to be a factor. However, reducing the disparity by raising the speed of the slower drivers means that there is much more kinetic energy on the roads, especially with kinetic energy increasing with the square of velocity. (20% faster speed means 44% more kinetic energy.) This is further exacerbated by a trend towards larger vehicles, such as SUVs, since kinetic energy is also proportional to mass. In an accident this energy must be dissipated and the amount of damage will generally be related to this energy.

      So, while accidents may happen less often, the average and total damage caused in an accident may increase, including death rates. Accident rate is only part of the equation. Again, the death rate may have indeed dropped, but it isn't a given just because the accident rate dropped.

    2. Re:higher speed = lower accident rate by Afrosheen · · Score: 5, Interesting

      Something like this is really hard to qualify because there are so many factors involved.

      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.

  8. Re:Hybrids not the answer by TooMuchToDo · · Score: 5, Interesting

    Leo,

    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.

  9. Re:Less Cars by Dun+Malg · · Score: 5, Insightful
    Everyone should have motorcycles and have less cars. Even though motorcycles are less efficient they take a lot less petrol/gasoline to run.

    I have 700 grams of stainless steel in my left leg that says that the potential price of a motorcycle is much higher than any amount of fuel efficiency.

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    If a job's not worth doing, it's not worth doing right.