My 2001 Prius was one of the first made. This winter was too much for it and I had to get a new high voltage battery put in it last week at Toyota. Mileage is awful! Although slowly creeping up, it is barely 20 mpg after driving about 30 miles, city. Toyota Service said that was normal and it will take 400 or so miles to get back to normal hybrid mileage, they said. True???? Please let me know, if you've gotten a replacement battery (and the one I got is certified, Toyota, new) what was your experience?
Most report exceptionally better mpg's after HV battery replacement. I don't know why it would take 400 miles or more???? That doesn't pass the smell test. Does it appear to be operating normally?
Replaced the one in my daughter's 2001 a couple Summers ago at around 125k miles I think. Installed a new one purchased from Toyota. I do not recall mileage being low and any "break in". Sounds fishy to me.
It does not seem to go into battery power mode very much, consistent with poor mileage. I'm taking it back to have them check their work.
I got a stock new one from the dealer on my 2001 and the mileage was the same afterward. No break-in recommended or needed. Around 37 MPG for mostly city driving with some highway.
There are many things that can cause poor mileage ranging from methodology to vehicle operational modes and route. Weather, temperature, plays a big part but other, undiagnosed problems can also run the mileage into the dirt. When your temperatures run above 55F, could you repeat the test and hopefully use a highway loop? You want a way to set the car on cruise control at a fixed speed; reset the trip meter, and; drive at least 10 miles at a constant speed. In a perfect test, a loop that returns to the starting point. Alternative, drive +10 miles, take an exit and return using cruise control at the same speed. This takes out the worst of the wind and elevation changes. Patrick Wong's replacement battery in California(?) showed a slight improvement for the first 3-4 months and then mileage reached a slightly lower plateau. I choose to replace the NHW11 modules with NHW20 in a ReInVolt built pack and saw no evidence of a mileage change but none was expected. To get 20 MPG, I have to drive the car at 95-100 mph but other than a race track, this is not sustainable for more than a couple of miles (with one exception in western Tennessee.) So we really need to understand your methodology: weather, route, speed, manual or cruise control, defroster ON/OFF, e.t.c. BTW, Eric in Madison WI is a Prius expert and independent shop. If you have the time, taking it to him for diagnosis would be a wise thing to do. Madison is a suburb to Chicago, right? <grins> Bob Wilson
