You too can learn to pulse and glide. I think you can only glide under approximately 40 mph. Faster than that and the engine spins to compensate for excess energy. If I understand correctly. Yet another write up on the record breaking run. "It is amazing what people can do if they put their minds to it and how a change in driving technique can make such a huge impact on gas mileage."
It is possible to ICE-off glide up to 41mph, but anywhere above that the ICE will at least spin even if no fuel is being consummed. Also, beyond 41mph it is exceptionally difficult to get a 'no-arrows' glide and sustain it. I generally use the upper limit of 39mph for my acceleration before glide as well...that gives a slight cushion in case I gain a little momentum on a down-hill or something so I don't exceed that 41mph limit and force the ICE to spin.
OK what if someone wanted to try that Marathon route to see how they could do in their Prius, but without the special mods to tires and oil? Can anyone figure the target mpg to shoot for if you had a regular car with 42/40 good tires and regular 5W/30 oil in it?
I asked Dan about that, he said they did it with CC on most of the time and got around 85mpg. I asked about having a "normal driver" do it, he said they could find one!
Wow, unfortunately I missed most of this from the weekend due to company being in town, but it's been great to catch up on it this morning! Do you know if we can get any hi-resolution photos of the group or the car for the 2006 PriusChat Calendar?
There are some photos posted elsewhere, unfortunately the quality is someone lacking. I'll ask the guys if they have one they think would be good.
efusco, Can you explain the "dead-band" thing a bit better. I have gotten pumped after this and have been expermenting with it. I can get the ICE and MG1 to run sending power to either the battery or MG2. I can not get the ICE to run alone at city speeds (50-25mph) Is the dead band you are talking about when the ICE is driving MG1 and powering MG2 but not involving the battery at all, either in or out? I want to push the car above the low to mid 50 mpg.
dead band acceleration is when there is no energy flow to or from the battery. I think that if it is teetering on the edge and going back and forth between to and from the battery then you are doing great. very little flow to and from the battery is almost as good as none.
I have learned a lot as a result of participating in the marathon. The first thing that we could all agree on is that there seems to be no correct way to accellerate. The Prius is very forgiving as long as you keep acceleraton within the 15 - 50 MPG range. Maybe the range is even wider but we did not try anything outside. Rick used 15-20 for his 115 MPG shift, I used 25-35 for my 115 MPG shift and Wayne used 40-50 for his 120MPG shift. The extra 5 MPG was more likely due to gliding down to much lower speeds than Rick or myself. What I found best for my style was not deadband at all. It was what I call "accelerate with charge". I found that during the night the headlights made it difficult to maintain the HV battery charge so I had to revert to "accelerate with charge", pink arrows from ICE to wheels, green arrows from MG to battery, no orange arrows at all. This kept the battery level steady. I continued this technique on my second shift in the daytime and found that I had an abundance of charge (no headlights) and I could actually use stealth to help me over small hills instead of using the ICE. This is how I went from 105MPG to 112 MPG. So much for my deadband habit. Another habit that I broke was to glide partially up a hill and then switch to ICE power to pulse the rest of the way up the hill. I switched to DWL (drive with load) in which I switched to ICE power as I approached the hill, held the gas pedal steady at 50-60MPG while I slowly bled off the speed, targeting 32MPH at the peak of the hill. Combining those two changes, on my last shift, I was over 117 MPG before I decided it was time to end this marathon. Unfortunately I made that decision about 3 miles too early. Dan
Dan- I agree with everything you just said from my experience. The problem is that we have to compromise to keep other drivers happy so accelerate with charge is usually too slow. I would really like to see you achieve 128 MPG so we can claim one mile per ounce of gas. This latest effort got one miler per 1.17 ounces of gas.
For whatever it's worth, theres a blurb about you guys over at autoblog http://www.autoblog.com/entry/1234000147053641/ - Bill
That would be a bit extreme, as that would be 256 miles per gallon. On a side note, I just registered (I've been over at PriusOnline for a while, and have read PriusChat for a while, but just registered,) and have to say one thing: I went to college with the commander of the Space Shuttle (Eileen Collins,) and know her as an 'acquaintance'; yet I was more enrapt by this feat of eco-friendliness by total strangers than by the status of the shuttle landing!
Hi Vincent, Thank you for the nice spreadsheet. I don't understand what is the exact problem, but I'm going to try to solve... There is an ICE-ON distance counter internally on SuperMID, but the distance is not displayed because of lack of display space. For example, from the first Dan's data... Fuel used: 4.501 L ICE-ON FE: 12.41 km/L ICE-ON distance: 4.501 X 12.41 = 55.86 km (hidden ICE-ON distance) then Percent ICE-ON: 55.86 / 200.38 = 0.279 or 27.9% Is this calc clear for you? Ken@Japan
Vincent, your spreadsheet is just as I was trying to develop, except you have kept in some of the seconday info I had skipped. Yours is better. Do you approve if I post it on other Prius groups with credit to you? DAS