Consumer Reports tried plug-in conversion kit on Prius. got 42 to 67 mpg. over first 35 miles.

[JohnWxy]

http://www.autobloggreen.com/2009/01/06/consumer-reports-tests-plug-in-prius-conversion-finds-it-lackin/


...CR purchased a Hymotion L5 plug-in Prius conversion kit from A123 Systems, and testing proved to be a mixed bag. We don't have full details to share regarding the kit's installation or full fuel mileage statistics, but CR's press release indicates that the PHEV managed to increase its mpg rating from 42 to 67 over the first 35 miles of driving. Perhaps this will be an ongoing series from the consumer-oriented publication. While that kind of mileage increase is meaningful, it would take a very long time to recoup the $11,000 purchase price of Hymotion's kit. Still, "the technology itself proved viable," according to CR.

[phantom power]

1. $11K ?

Seriously?

[DCKit]

4. AFAIK, the current price for an Li batter pack capable of powering an automobile...

for any distance is ~$10K. We desperately need the economy of scale in battery manufacture. Until these things are mass-produced, by multiple companies, they're going to be an expensive gimmick.

On a lighter note, Tesla motors says they expect a replacement battery pack for their new car will cost about $5K.... in about seven to ten years when someone actually needs to replace the battery pack.

It has always been my contention that electric cars should cost less than ICE cars - the layout is more flexible, the motor and batteries take up less space than an engine and gas tank and, with a fraction of the moving parts, less complicated to build. Additionally, maintenance on an electric vehicle is greatly simplified.

[AlecBGreen]

2. IIRC

a couple of electrical engineers did it themselves for $2500. anybody else remember this?

[toska]

3. only 35 miles?

What's the point of testing the car if they start reporting results at 35 miles? In a regular Prius, the first 15 minutes or so are the worst because the engine has to warm up. So they should see a difference at that distance. The speed they drive is also key. I don't know about the plugin-in kit, but the stock Prius can run electric only up to about 34 mph (under very conservative accelerating). But why not run a tank or two under a variety of road conditions before drawing a conclusion? Or is there a particular outcome they are advocating?

To properly evaluate the conversion kit you need to know if the car is reprogrammed to handle the larger battery. When does it start up the gas engine? What temperature was it outside? You can easily get a 5-10 mph difference between winter and summer. CR should have waited before issuing a press release.