Sunday, March 23, 2008

Toyota Prius--A Few More Comments

Toyota Prius--A Few More Comments

During the time that my wife and I drove a rental Toyota Prius, I grew to both love and hate different aspects of the car.


Loved

1. The rear view camera--it made it possible to get really, really close to the car behind when parallel parking without worry about colliding. Especially on a rental car, that's very cool.

2. It was very compact, which was excellent for D.C. traffic.

3. I averaged more than 41 mpg during the roughly 250 miles I drove it. On Interstate, it was consistently hitting about 50 mpg. Around town it was more like 25 mpg. Compared to the EPA estimate of 48/45 mpg, that's okay.

4. The touch screen display allowed you to display not only bar graphs of mileage over the last 30 minutes, but also showed a schematic of the battery, electric motor, and gasoline motor. It was easy to figure out from the schematic if you were operating entirely on battery, a combination of battery and gasoline motor running the wheels, or the gasoline motor recharging the battery.

5. How quiet it was when stopped. This took some getting used to, because my first reaction, and that of my wife when she drove it, was that the engine had stalled. No, there's just no need to run anything when you are stopped.


Hated

1. The touch screen display that it uses for the rear view camera, schematic display, mileage information, air conditioning controls, and stereo controls--is all one display. This means that you can't easily change one set of controls without losing information.

2. The driver should be able to set air conditioning or stereo controls without taking his eyes off the road to look at the touch screen display. Maybe there was a way to do this, but it sure wasn't obvious to me. This is potentially dangerous--especially on a rental car, where the person driving it is unlikely to have read the manual before driving away. A more conventional design--where you can adjust settings with knobs and no real need to look away from the road, would be safer. Or use the heads-up display that GM uses for some of their cars.

3. The touch screen display was not bright enough in direct sunlight to easily read. That's potentially a safety issue.

4. My wife was of the opinion that the touch screen display was distracting to the driver. I found myself having to force myself to not watch it--and under certain conditions, this might be a problem. You can turn it off, but this seems like a suboptimal situation--where you turn off a display that can provide useful information, because it is so active.

5. I found that to start the car, I had to put in the key, press the START button, then press it again to turn off the car, then press START again. Otherwise, there was no way to get it into gear. The first couple of times I thought that I had missed some step, but I was convinced by the end that this was intentional. Maybe there was a reason for this, but especially on a rental car, this seems stupid.

6. Having a button to put the car in Park separate from the Buck Rogers transmission selector works okay--but it is so different from the traditional automobile user interface that I am sure it is going to cause some accidents, somewhere along the way.

7. While it had plenty of punch for city traffic, it was a little disappointing merging on to freeways. Not really bad--but I suspect that passing on a two lane road at 60 mph might require considerable care. (Okay, the Corvette has spoiled me on this.)

I realize that the Prius is something of an experiment, but I'm not sure that this makes sense except for the trendily green. You are going to spend $21,000-$23,000 for a new Prius. A Chevy Cobalt can be yours for about $13,000-$15,000 (unless you gotta have the SS model).

The mileage on the Cobalt isn't as good as the Prius (and remember that there are plenty of similar sized cars that do better on mileage than the Cobalt). The EPA estimates for the Cobalt are 22/31; my daughter often gets in the high 30s on open highway, so the Cobalt is going to cost about three cents a mile more to operate than the Prius (at $3.25 per gallon). But with an $8,000 difference in purchase price, that will take 266,000 miles to recoup the difference. The Prius will probably hold its value better than the Cobalt--but still--that's a lot of miles.

One of the early concerns about hybrid cars was that the batteries, when they wore out, were going to be expensive to replace. This web site says not to worry--at least about the Prius:

And Toyota claims that not one has required a battery replacement due to malfunction or "wearing out." The only replacement batteries sold--at the retail price of $3000--have been for cars that were involved in accidents. Toyota further claims that the nickel-metal hydride (NiMH) battery packs used in all Prius models are expected to last the life of the car with very little to no degradation in power capability.

For those of us who have cell phones and other devices with NiMH batteries, that claim may sound unrealistic. Over time, the battery's charge longevity seems to wane, resulting in shorter and shorter usage between charges. Eventually, the battery becomes worthless and we buy a replacement.

But in the case of most electronic devices, the batteries tend to get fully charged, then nearly fully discharged before being charged again. For the power pack in the Prius, at least, Toyota says this would greatly shorten the life span of the battery.

...

According to Toyota, the life of the Prius battery pack is determined more by mileage than by time, and it has been tested to 180,000 miles. Supporting this are first- and second-generation Prius taxis in Canada that have reportedly traveled more than 200,000 miles without suffering any battery problems.
I suspect that at some point, the price of gasoline is going to make the Prius and similar hybrids make a lot more sense than it does now.

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