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Old 09-01-2009, 03:43 PM   #13 (permalink)
WoodyWoodchuck
EcoModding Wanabe
 
Join Date: Jan 2009
Location: Wake Forest, NC
Posts: 10

Red Rocket - '08 Toyota Yaris
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I have only had experience with the rolling hills of central NC so can not say about larger mountains.

It was challenging at first because the distance between hills varies and the EOC is usually much shorter than you would like. Meaning you could coast for a much longer distance than the hills allow. I learned to just go with the flow. Say I pulse to 50 mph in a 45 psl zone and EOC on top of a small hill. I coast for… maybe ¼ mile and get down to 40 mph. My choices are to pop the clutch and accelerate to 50 mph to begin the next hill climb or coast another hundred yards right to the bottom of the hill before popping the clutch going 35 mph. (These are fictitious numbers, for example only). Which one works better for total trip mpg? It really depends on the hill you are about to climb and the next EOC coast on the other side. If it is a sloooow gradual climb then I gain some momentum to DWL the hill. If it is a shorter climb I coast right up to it then accelerate more aggressively for a few second before DWL up it.

The technique that works best in all circumstances is only possible with no traffic behind you. That is to start at the psl and coast whatever the distance available is. Then DWL the hill according to your end of coast speed and EOC the next downhill at whatever speed you are at. I’ve had a few days where I tried this on my commute and the results were fantastic! I had a few EOC starts going 25 mph and coasting down to 10 mph. I also had EOC starts going 40 mph and ending at 36 mph. What screws the whole process up is that vehicle appearing in your rear view mirror and you have to accelerate to the psl before they get to you. Unfortunately this happens when you are going 15 mph right at the bottom of a steep hill!!!

Bottom line I have come to think that small rolling hills will return better mileage than large mountains like Brian climbs. There is just no way to get back most of what you put into the climb. Small hills you lose much less climbing so do not need to gain that much more coasting.
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