Another Stab At Sorting Hybrid Hype From Reality

Attila Dimedici writes "Eric Peters makes the case that hybrids have been over-hyped. His argument is that in order to sell people on hybrid cars, automakers have emphasized the energy efficiency of hybrids in ideal conditions and failed to tell people that in most ordinary driving conditions they will not come close to meeting the numbers given. He refers to a recent case where an individual has chosen to forego membership in a class action law suit and has instead chosen to go to small claims court. He suggests that there is a significant chance that she will win there and that this will open up all of the manufacturers of hybrid vehicles to similar lawsuits. The article was on a rather partisan website, so I am curious what factors he has chosen to overemphasize to make his case. (Or what factors he has chosen to ignore to the same end.) I know that Slashdot has a large contingent of hybrid and EV supporters who are well educated on the subject (as well as a large contingent of those who are not so well educated)."

Comments

I can counter his example with my own

[dirk]

I bought a 2011 Prius IV, and it works exactly as advertised. I drive about 15 minutes each way to work, about half highway and half road, and I get about 49 MPG, which is exactly what was advertised. The idea that you have to stay below 50MPH and never accelerate or go up hills is just silly (I live in Cincinnati, OH, which is fairly hilly as well). I have learned to not slam on the gas when I am taking off, but that is because it shows you your efficiency real time, so it's easy to see what you are doing to your mileage when you take of like a race car. Generally, I drive it like any other car, although the information it gives me allows me to drive a little better than I did in the past.

And I'm sorry, but no car will get the advertised gas mileage if you are going up mountains. This has nothing to do with hybrids and everything to do with that fact they don't take into account extreme driving conditions when they calculate mileage. This is actually the first car I have ever owned that gave me the gas mileage it advertised.

Also not their decision

[pavon]

The EPA defines how energy efficiency numbers are calculated, and those numbers have to be displayed on the car. The car companies could advertise a lower number, but there is no simple one number that tells the whole story, and you can't give a full technical report in a 30 ad. By all using the same system to determine the fuel efficiency at least the numbers are relatively meaningful even if the absolute value isn't directly true for all circumstances.

Finally, good luck suing a company for false advertising when the numbers they are using are determined by government testing, not by the company.

My 2004 Prius still gets close to the EPA estimate

[Anonymous Coward]

I have a 2004 Prius with almost 200,000 miles on it. I have a 70 mile per day commute, 60 freeway/10 city, in Southern California. I drive at normal freeway speeds (for California), and had the carpool sticker which was discontinued last July. In the carpool lane, I was able to average between 75 and 80MPH during my commute, which has a few hills, but nothing major (I-405 South from 55 to San Juan Capistrano and back).

I have been averaging about 48MPG on this commute since the day that I got the car.

I am by no means a hypermiler, but when my wife drives the car, she is lucky to get 40MPG in the city, since she has more of a lead foot than I do. On a long freeway trip at 80MPH, she can get about 45MPG. I can get a higher mileage if I drive slower (65MPH or below). In that case it goes above 50MPG. If I get caught in traffic on the freeway, the mileage improves (during stop and go traffic).

My previous car was a Plymouth Neon that got 24MPG, so my MPG has been doubled for the last ~200K miles. According to my rough calculations, at that mileage, I purchased about 4166 gallons of gasoline since February of 2004. If you figure an average price of $3 per gallon (which is really not that far off for Southern California since 2004), that is $12,500. If I was able to keep my old car (which was going to require extensive/expensive repairs in order to continue operation), I would have paid $12,500 more for gasoline over that same time period. So therefore, I have saved $12,500 so far. The premium that I paid for the Hybrid system was less than that, so it has more than paid for itself. I ordered a Prius with none of the extra options except the side-curtain airbags which are now standard, so I paid quite a bit less than the fully loaded Priuses that they were selling at the time.

Hopefully my next car can be a pure electric, if I can make my Prius last that long. Maybe a plug-in Prius or Chevy Volt would be a reasonable alternative. That carpool sticker saved me thousands of hours of time as well (over the years). I really miss it!

Re:First Anecdote!

[Anonymous Coward]

Sheesh. So much garbage in one post.
So, I drive a Toyota Prius. It does get that good gas mileage advertised on the sticker. Yes, I do floor it from time to time. Yeah, some of the time I drive like I'm carrying eggs to the Czar, but I did that with the car I had before this one, too. Mostly, I just DRIVE THE CAR.
In no particular order:
1. The Prius does implement a CVT. It's electric, not with belts, and it doesn't slip. Power in vs. power out is no better or worse than a standard automatic, or maybe even a manual. Advantage: It allows the engine to spin at its most efficient spot for the power required.
2. The Prius's engine isn't, technically, an Otto cycle engine. It's Atkinson. Atkinson's have better fuel efficiency than an Otto, but they got lousy torque. Oh - look at that: There's a couple of electric motors in the drive train! These>do have torque, and lots of it. So, maybe this car doesn't leave rubber strips behind it when it gets floored. On the other hand, neither did my old Civic. Or the VW I had back in the day. On the straight and level this engine pulls 55 mpg at 65 mph, better at slower, worse at faster.
3. So, up and down? The engine on the 2010+ Prius has about the same horsepower as any car its size, so there's no trouble climbing hills. Yep, you do get less gas mileage when doing so. But, when you're going downhill, the Prius isn't shy about cutting off the fuel to the engine and dumping some energy into the battery. Yep, you only get some 30% of the energy back after taking all the losses in the electronics into account - but that's better than the 0% with a conventional car.
4. Braking. After the round trip through the batteries/electronics you get 30% of the energy from the stop. That's still better than the 0% that a conventional car gets.

In general, hybrid cars are just getting started. A good deal of the losses in a hybrid have to do with the silicon MOSFET transistors in the inverters that take energy out of/put energy back into/ the electric motors on a hybrid. In the near term silicon carbide transistors are coming. They have less RDSon (less resistance), switch faster, and can tolerate much higher temperatures than silicon. So, there's better electrical efficiency right off, hence cooling requirements are less, and, with the higher temperature tolerance, the transistors don't have to kept as cool. Therefore, the energy required to move all that cooling fluid around the inverters gets reduced by large double-digit percentages and the weight of the additional cooling gear also goes away. 70 mpg, anyone?

If you want to point fingers at idiots, then point them at the engineers and marketing people at other car manufacturers who, when faced with the Prius, built cars with stupid little electric motors bolted in the same place where one would put a starter motor, rigged said motor to give a bit of a power boost on acceleration, resulting in "Not Much Change", then had the gall to call such cars "hybrids". Even when the blame things got worse gas mileage than their non "hybrid" brethren.

If you want to have real fun, think about the gas mileage on a Toyota-style hybrid diesel. 90 mpg, anyone?

Remember: It's not just the more efficient Atkinson engine and battery combination. It's the energy recovery and the ability to go medium to short distances on battery alone with the engine off. The Prius really was a break-through. Everybody else is just playing catch-up.

Re:First Anecdote!

[Technician]

The one in a Prius does very well. The old style belt and variable pulleys are not what I consider long life. The planetary gear set in a Prius with the pair of motor generators to implement a CVT has reduced the weight and complexity of a transmission to the point where all friction components (clutches, bands brakes) are eliminated along with all hydraulics. All mechanical shifting is gone. It has no clutches or gears that engage or disengage. This is true from freeway speeds forward to reverse. The only mechanical part that is shifted is the park cog.

I have over 160K miles on mine. At 100K I changed plugs. Other than that, it has needed only normal oil changes and such. With regenerative braking, it is still on it's original brakes. For a zero breakdown car with no mechanical issues, I have no complaints. The milage is less then the EPA estimate, but it is way ahead of any other car I owned. My lifetime average MPG is 45.3.

I have no reason to sue the manufacture for this. All cars by all manufactures did not do as well as the EPA estimates in 2002. Hybrids are no exception.

Never changing any belts, alternators, water pumps, brakes bulbs, etc in a decade of commuting is a great trade off. I have had to change the small 12 volt battery a couple of times, ~5 year intervals, and tires about every 60K is not a problem.

The gas savings over my old car with 160K of driving is considerable. The cost savings in maintenance is a bonus. Not meeting EPA guidelines on MPG, not a surprise for city traffic. Stoplights and traffic kills millage. I'm impressed it does as well as it does.