Replace HV Battery: Toyota vs Re-InVolt

I highly doubt this for more than a few miles. I mean the display will say that, and you are getting 70mpg for that stretch of 2 miles at 30-40mph. However it is using quite a bit of the battery, and at the end of that mostly electric section, the battery is at half charge. It will have to make that up somehow, so the overall mpg is not 70mpg. You can look at the plot of distribution of mpg for gen I and gen IIs it looks pretty gaussian, so yeah some percentage never see more than low 40s mpg. But tire inflation makes a big difference.

 

I drive for efficiency so I'll offer a couple of suggestions before listing my practices:

• Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - people who 'turn a wrench' and drive efficiently
• CleanMPG, An authoritative source on fuel economy and hypermiling - a little too OCD for my relaxed style

I break driving into peak maintenance, exploiting vehicle 'niche', and relaxed driving.

MAINTENANCE

• Fully inflate tires to maximum sidewall pressure - near the rim, embossed in the rubber. Some folks recommend 2 psi higher in the front than the rear to match the weight distribution and 'handling.' Top off every 4-6 weeks.
• Oil level under "F" - as long as it is under or at "F", no problem, but anything over is bad news. Consider using just three quarts on your next oil change to see where it falls on the dip stick. Overfilled oil leads to excessive internal friction and oil loss that can show up in the intake manifold and/or out the rings to destroy the catalytic converter.
• Fall maintenance - change oil, new oil and air filter, check cabin filter, and install the lower bumper, air inlet block. Check tire tread looking for abnormal wear patterns indicating a need for wheel alignment. Every two or three years, replace wiper blades. Use a winter grade oil if it is pretty cold.
• Spring maintenance - change oil, new oil filter, clean air filter, remove lower bumper, air inlet block (used below 50-60F), Check tire tread for alignment issues. Use a summer grade oil.

DRIVING TRICKS

• Get ready before READY - seat belts, radio, windows (generally down) and look for traffic.
• Catalytic 'light off' - there are 45-55 seconds before the catalytic converter gets hot enough that the car has a limited EV mode. When there is a traffic break, start car and modestly (engine RPM under 1,400 rpm,) smoothly accelerate to speed and shift into "N". You'll use the traction battery energy to achieve the 'coast' speed and then shift into "N" which disables power flow ... saving the traction battery. This lasts for less than a minute but remember "Drive the car."
• Warm-up to 70C - it takes just over 5 minutes for the engine at idle to warm the coolant to 70C, the threshold that allows the engine to 'auto-stop'. During this time:
  • minimize speed - I cut through my 25 mph, neighborhood rather than heading to the higher-speed, cross-town roads.
  • maximize "idle" - shifting into "N" prevents the engine from burning more fuel to recharge the traction battery and has almost no impact on warm-up time. Use "N" to save fuel including when stopped. Regenerative braking requires "D".
• Stage 4 - first document by Ken@Japan who brought it from the Japanese Prius enthusiast, it requires the engine coolant to be at least 70C:
  • engine auto-stop 32-41 mph - it helps to let the engine stop by coasting down in the 32-41 mph speed range. This sets a 'soft' flag to help get into stage 4.
  • stop for 10-15 seconds for 'auto-stop' - the first time the engine shuts down by itself while stopped, signals the car is in stage 4 and will auto-shut the engine at any speed under 42 mph that it can. Just 'drive the car.'
• Speed range 0-38, 45-65 mph - I like to keep a 'dead band' around 42 mph so minor speed variations won't cause unnecessary engine start-stop operation.
• Use cruise control - let the car handle speed management and give your right foot a break.
• 55 mph up steep, 8% grades - if your road has a truck climbing lane, use it and climb at a maximum fuel efficiency speed to go up tall hills. I love to follow heavy moving trucks in the truck lane.
• "B" when descending tall hills - using "B" reduces traction battery heating and heat is the enemy. Often you can descend the hill without touching the brake. If it is too slow, shift into "D" until speed is OK and then back into "B."
• Try to use windows instead of AC or AC blowing at face with maximum velocity and highest tolerable temperature. Higher blower speeds and a warmer temperature uses less engine power than cooler temperatures, lower speeds, and cooling the feet.

OTHER STUFF

• low rolling resistance tires - we live in Huntsville, AL, and have mild winters. If it snows, they shut everything down for a day or so before we go back to work. I'm using Sumitomo T4s which I run at 51 psi but these are not a winter tire. In snowy areas, having a second set of winter tires already mounted on cheap rims makes a lot of sense and/or use chains.
• four-wheel alignment - normally only front toe is adjustable. However, there are camber bolts for the front and wheel shims for the rear wheels that handle both toe and camber. These are more for maximizing tire life.
• maximum diameter tires - maximum, diameter tires on the front improve straight-line stability. However, they cause the speed to read 6% slower, distances are 6% lower, and MPG looks to be 6% lower. But having calibrated the error using both highway mile markers and GPS, the extra stability is worth more than having to deal with a calibration issue. If doing the corrections in your head is a bother, most GPS units will report true speed and distance. <GRINS>
• Type T-IV vs Type WS transaxle oil - a very subtle effect, I'm still running the experiment. I also change my oil every 30k miles but as the test results come in, I may lengthen the period.
• Scangauge or equivalent - try to keep the engine rpm under 2,600 rpm and definitely under 3,900 rpm. Between 3,900-4,500 rpm, the engine begins using fuel enrichment to reduce exhaust gas temperature and save the catalytic converter. It also reads out engine coolant temperatures and with XGAUGES, a wealth of vehicle information.
• Summer, park in shade - walking across the parking lot is much cheaper than running air conditioner.
• Winger, park in sun - makes it much nicer to get in the car.
• Block heater - most useful when temperatures fall to 40F, use for at least 30-60 minutes, helps in the first trip of the day. Others run them longer and at higher temperatures, obviously personal preference.
• Transaxle oil pan heater - also help whenever the block heater is being used. However, I've had two fail, the power cord 'breaks.' Work hard to mount so there is no vibration between the power cord and pad.
• Park close to exit - so you can maximize the limited, EV mode during the initial 45-55 seconds.
• 12V tire air pump with gauge - it is much easier to keep the tires fully inflated with your own tire pump.

So looking at my list, imagine what it means if I consider others to be OCD. <GRINS>

Bob Wilson

 

Hey Joe, don't doubt, try it. I'm not talking about using any EV at all for this and I'm definitely not going to limit it to 2 miles. I think you're misunderstanding me. I'm talking about this situation, ICE on and driving the wheels and battery charging like this (Gen II display, sorry but Gen I is similiar w/out Current MPG reading).

I have found that once you get to speed, say ~35-50mph, you can hold that speed in this mode and easily get 60-75mpg's (flat surface assumed). Additionally, you will be charging your battery not depleting it. At the end of the run, you should be fully charged not half charged. Then... you can use some of that charge (not too much though) to extend a glide or, accelerate. Trust me, you will easily get 60-75mpgs on a flat surface @35-50mph in this mode. Try it, you'll like it.

 

They allow you to buy from them and install yourself?
Also, is the warranty still good if you install it yourself?
My 2006 160K prius went dead a couple of weeks ago and we ar looking into reinvolt.