214K on Original HV Battery

good work, let us know how the mod goes when you get into it. all the best!

 

Looks good Chris. We like to see stories of traction batteries exceeding 200,000 miles here.

You may just need to get a little more used to driving it to get the best efficiency around town. Remember that there are factors of around town driving that both increase and decrease fuel economy.

The main reason that around town driving improves fuel economy is the lower speeds and consequent lower aero losses. Other factors however, such as more frequent stops and more acceleration braking cycles, actually hurt fuel economy. It depends a lot on the speed limits as well. The prius has an economy "break point" at about 42 MPH, due to an idiosyncrasy in how the HSD works. If you can keep your "around town" speed to largely under 42 MPH, and practice gliding as much as possible (especially when slowing down for lights and intersection etc) then there's a good chance that you could get your around town MPG up .

The other thing that may help is to google the "five stages of hybrid operation", and attempt where possible to get your prius into the elusive "hybrid stage 4" during the around town trips.

 

When I used to commute to work, I used to see better MPG on the highway than in the city. The moderately heavy traffic kept the overall speeds down but with some buffer space in front, I was able to keep the speed relatively constant and minimize the full stop/acceleration cycles of city driving. In the summer time, I'd average a few weeks of 70 mpg on the highway commute--haven't been able to match that in city driving.

 

Is that 70 miles per US gallon tanglefoot? If so that's some pretty impressive hypermiling. I can manage 70 MPG-UK pretty easily, as that's only 58 MPG-US, but 63 MPG-US is the highest tank average I've ever recorded.

 

What is your average highway speed, around 50 or 60 mph?
Are you running the air conditioner?

 

US gallons. The speeds were usually lower--around 30-50mph in the moderately heavy traffic. It included a stretch of crawling in stealth mode on the way home. I probably didn't use much A/C, maybe sometimes on its lowest fan speed.

 

Nice! So that's about 84 MPG UK, or about 3.36 L/100 km as we use here in Aus.

 

This is quite reassuring. I have a 2007, with about 116K on it, was recently thinking about the HV battery. I read somewhere that in California, the batteries are warrantied to 10yrs/150K. Is this true? So what happens if it dies before this warrant expires, can you just take it to any Toyota dealer and expect to get it replaced for free?