Help requested: New Prius hypermiling event!

Discussion in 'Fuel Economy' started by billy, Apr 26, 2014.

  1. billy

    billy Well-Known Member

    Hi All, Wayne has been helping to get me up to speed (by cell phone) with this methodology, but I thought I'd post this for mutual benefit.

    Here in Eastern WA, I have a friend who's the General Manager of a Toyota Dealership. He has designed and planned a charity event, complete with sponsors, donors, radio & TV attention, community involvement, etc. The feature of this event is a Prius mileage run, with the goal of achieving maximum number of miles from 1 tank of fuel. The idea is: 3 different drivers, (only 1 in car at a time) 50 mile course in the local area, never, ever allowing the car to come to a complete stop (2 mph driver changes).

    The event will be in early August when the daytime temps are near 100 F. With an average speed of around 20 mph, this should take more than 50 straight hours?

    As many of you know, I am GEN ONE Insight driver. So yesterday I did my first practice/exploratory run. The dealer GM pulled a beautiful blue, BRAND NEW Prius package 2 out of inventory and handed me the key and said to go have fun for 3 or 4 hours. The car smelled wonderful inside, and had only 4 miles on it!

    I have tentatively chosen a local route that has almost no traffic, pretty flat (a few very minor slopes), and there are NO stops signs or lights at all. Yesterday's conditions: Bridgestone Ecopia tires, 55 lbs of air, ambient temp 62 F, no significant wind.

    First I got familiar with the dashboard displays and gauges. Then I drove the my starting point. Put the car in DRIVE and held the brake while nearly flooring the gas pedal, and the battery charged fully. Then as I slowly departed I zeroed trip A.

    Very simple: I very slowly accelerated to 30 mph, slightly let off the gas pedal while pulling the shifter over into neutral. Coasted down to 15 mph, then put it in DRIVE and accelerate to 30 mph......repeat....repeat. I did this for 40 miles on this test. Wow, for the first 18 minutes the ICE never came on. After that, the ICE came on EVERY time as I accelerated very gently to 30 mph. Also, I was very careful to estimate the "crowns" of any small hills, so that I began the glide at the right time, etc.

    Results: I estimate 104 mpg. The display stayed at 99.9 the whole time. So when I got on the freeway for a high speed test, I carefully watched how long it took the display to come down below 99.9, and then it's rate of decent. Based on this, I estimate 104 mpg.

    So, is this proper technique for 50 hours of driving? Are my speeds too fast? What are some better ways to do this? I would like to average around 112 mpg if possible. (then I have to train 2 other people how to do this! Billy....
  2. Harold

    Harold Well-Known Member

    You probably used as much gas charging the pack as you did on the test circuit? Slipping into neutral does not allow for regen of the pack during the mpg run from a full tank? Is there a way to regen without full throttle method. H
  3. Gageraid

    Gageraid Well-Known Member

    This sounds like a lot of fun.
    Are you allowed to mod the car at all? Maybe you could use ScanGauge?
  4. bestmapman

    bestmapman Fighting untruth and misinformation

    Hi Billy,

    It sounds like you have the technique down. I do it a little slower but speed vs time is a trade off sometimes. I would get the following.

    1) Complete grill block. Even in the hot temps if you are doing p&g it will help. If you do any hwy then don't fully block.

    2) Scan gauge is a must. The three things to moniter are water temp, rpm, and soc

    3) for the best mpg keep the wt at 190 min even in the hottest temps you will have to grill block to keep it there.

    4) As you know the engine is so smooth, you will need something to verify the engine has shut down.

    5) Soc - keep it right at 60%. Depending on the topography that will give you your best result. I suspect you used some of the battery when you first started up.

    I will try to post some techniques later. But I use neutral ALL the time.

    Also, check with Wayne, but I think the PIP has better programming and may yield better results even with no charge advantage.
    Last edited: Apr 27, 2014
  5. ksstathead

    ksstathead Moderator

    I'd tend toward stopping for driver changes on top of a hill.
    Safety plus virtually no difference in results?
  6. bestmapman

    bestmapman Fighting untruth and misinformation

    I agree. Stopping would be much safer.
  7. EdwinTheMagnificent

    EdwinTheMagnificent Legend In His Mind

    Yes , please stop for driver changes. We don't want folks to think that hypermilers are a bunch of nutters.

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