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Old 07-25-2011, 07:31 PM   #12 (permalink)
SentraSE-R
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Join Date: Jun 2009
Location: Bay Area, California
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Mean Green Toaster Machine - '06 Scion xB
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Quote:
Originally Posted by busypaws View Post
Anybody have a rule of thumb for difference in speed at start and end of pulse. It seems to me that anything less then 10mph makes it inefficient. I.E. I try to top out at 60mph and then glide down to 45mph. This on a 65mph road with little traffic. Only coasting down to 50mph seems ineffecient.
My experience parallels yours, busypaws. A 15 mph delta works better than 10 mph at higher speeds, and 20 mph is even better. I use the same 60 mph upper limit with my boxy xB, so the only roads where I can use the wider delta are non-interstate, lightly traveled highways. 40 mph is illegally slow on most highways.

I P&G with 10 mph deltas in 2nd and 3rd gears. What's really important is the ratio between pulse time & glide time. It's something like this:
Code:
Gear  pulse time  glide time  ratio P:G  speeds  mpg
5th      8-10        8-16        1:2      45-60   50  
4th       8           24         1:3      25-40 55-60
3rd       6           40         1:7      20-30 60-70
2nd       3           30        1:10      10-20 80-95
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Boycotting Exxon since 1989, BP since 2010
Have you ever noticed that anybody driving slower than you is an idiot, and anyone going faster than you is a maniac? George Carlin
Mean Green Toaster Machine
49.5 mpg avg over 53,000 miles. 176% of '08 EPA
Best flat drive 94.5 mpg for 10.1 mi
Longest tank 1033 km (642 mi) on 10.56 gal = 60.8 mpg

Last edited by SentraSE-R; 07-25-2011 at 07:40 PM..
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