Tinkering with the Prius

IMHO, here are the things that most affect the Prius's efficiency:

1. Driving Style
2. Weather
3. Tires/air pressure/alignment
4. Maintenance

There's really not much to adjust or maintain on the Prius. The air filter getting dirty is about the one thing I can think of, along with eventually cleaning the throttle plate. Everything else is controlled by the computers in a closed loop fashion. Its measured, adjusted, re-measured, and re-adjusted continually so things are pretty much always correct. The main thing you can do is learn how to drive it. That doesn't mean driving unsafely, or like a grandma. It means developing a deep understanding of how the car works, and how to convince it to operate in the most efficient fashion as often as possible. A good start on this path is to invest in a scan gauge, and spend a good deal of time reading the threads on this list regarding how to use it to know what the car is actually doing internally at any given time.

If you haven't already, one of the biggest things you can do in winter is install a block heater and grill block. Getting the engine up to temperature sooner, and keeping it warmer longer makes a big difference. Even here in Phoenix I run a half grill block in winter, and know people who use block heaters. You'll also find a lot of threads on these topics. Ideally you would use a scan gauge to monitor temps so you can run as much blocking as is safe in your climate/driving conditions.

Any more hardcore manipulation would require changing settings in the engine computer, HV controller, and battery computer. Since a lot of these settings are in place to protect the electric motors, inverters and batteries, and to keep emissions low, changing them is pretty risky, and potentially illegal. A few of the PHEV conversion folks have started on this path, but even they haven't really tried to change the ECU or HV controllers yet. Just the battery management system.

Rob

 

Most people are not getting those numbers in the winter.. I am down to about 52-55MPG, but in the summer I had like 15 tanks over 60MPG..
Tire pressure helps a lot and learning to P&G will really boost your numbers, but to get over 60MPG you must be willing to slow down especially on the interstate I average about 64MPH..

Trust me I am the average Prius driver. I have had my Prius for about 10 months and if I can do it anyone can..If you are really serious about learning how to get those type numbers and you live close to one of the Hybrid MPG groups (like the Milwaukee Hybrid Group or the Cincympg Group) Thats a great place to learn..

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Why do people think to get these numbers that we hypermilers drive unsafe its just the opposite we drive much safer than the average driver by going slower and always looking ahead..

 

If you want to keep yourself busy tinkering, might I suggest:

1) Change the power steering fluid regularly.
2) Every 20 k miles or so, replace the cap, rotor and spark plug wires.
3) If you play your stereo loudly, I'd drop in a high current alternator in there.
4) Put a beefier clutch and a stronger spring plate in there too.
5) Get yourself a Teflon lined throttle cable to minimize wear.
6) Adjust the idle; Priuses tend to stall out at stop lights.

I'm sure the regulars here can help out with other similar improvements!