burn and glide @ 70mph - Page 2 - Fuelly Forums

Android Users - Coming Soon! - Migrating from aCar 4.8 to 5.0

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Old 07-04-2007, 10:48 AM   #11
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I thought it took more fuel to return the vehicle to a speed than it does to keep it at a constant speed?
A lot of people lately have been using WOT. Wide open throttle or near it, since in Theory that is where the engine is most efficient.

Idea being you need a certain amount of energy to go a distance. You might as well generate that energy at your engines most efficient.
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Old 07-04-2007, 11:01 AM   #12
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Quote:
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I thought it took more fuel to return the vehicle to a speed than it does to keep it at a constant speed?

The problem is more severe when starting from a complete stop than when doing P&G from a lower speed to a higher speed. Shutting the engine off is what makes this most efficient.
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Old 07-04-2007, 11:38 AM   #13
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I thought it took more fuel to return the vehicle to a speed than it does to keep it at a constant speed?

I've always thought the same . Try it -you'll be surprised . I've been playing with 50-60 LOD ranges for burn or pulse(will be trying higher, maybe up to 80 LOD) , it seems to give more coast time as well as more frequent opportunities to do so. I'll have to admit for all these years of light throttle to achieve FE - I've been wrong .
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Old 07-04-2007, 11:49 AM   #14
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I think I read somewhere that 80-90% is the best range. I'm usually around 85%.
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Old 07-04-2007, 12:35 PM   #15
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Good to know ! I've been winging it - s'be able to save some test time. TY!
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Old 07-04-2007, 04:38 PM   #16
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I have been babying it, mainly due to driving conditions. My car has horrible gearing (3 speed auto) so I can't really do much with gliding-anything. I will however start trying heavy acceleration up to cruising speeds. I wish I had a tachometer. Damn, my car is horrible for measuring FE.
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Old 07-05-2007, 11:51 AM   #17
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What gives better FE. Driving at a respectable 60 mph or P&G from 70 to 60. I know that P&G from 70 to 60 is better than doing the average of 65 mph. But since 60 is at low end of the scale, Im thinking that going slower might do more for FE than pulse and glide.
Another question: Does pulse and glide really help that much at slower speeds. I know that wind resistance gets worse as we increase speeds. But that FE drops significantly once we pass 55mph, depending on your car. But I think the huge drop at highway speeds may be due more to engine braking than wind resistance. Best FE for a certain speeds requires that we be in the correct gear. No one will drive at 40mph in 2nd gear. Our car CAN actually do it but that speed is more comfortably/efficiently done in 4th gear. Cars will automatically slow THEMSELVES down once you let pedal go at 40 mph in 2nd gear. The same is happening when you go 75mph in 5th gear. 75 mph is more suited to a 6th or 7th gear (which we dont have). Thus the benefits pf P&G are more noticable at higher speeds.

Which is why I wonder if P&G is even needed when going at proper 5thgear speeds of 55mph. Would I be better off doing 55-60 or pulse and gliding from 75-55??, or somewhere within that range. I cant wait till I buy a ScanGuage II
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Old 07-05-2007, 12:13 PM   #18
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Somewhere I saw a post comparing steady speed cruise control vs. P&G using moderate acceleration, I think maybe 1/3 throttle or so. P&G wone every time.

The center speeds tested were 35-44-55 mpg, if I recall. That is, at each speed, he compared steady speed vs. P&G from 5 mph under to 5 over the center speed. I don't recall if that was engine off or coasting in neutral.
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Old 07-05-2007, 12:45 PM   #19
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My own results with P&G were disappointing, tried it for a couple of tanks on my truck and lost 2MPG. I just went back to my old way of driving, which is just go about 10MPH over whatever the speed limit is, provided it's in an area that I know to not be populated by ankle biters.
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Old 07-05-2007, 02:07 PM   #20
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This a.m. drive : 70-80 LOD pulse (or 36-40 TPS ) ,speeds of 40-55 mph ,IAT 64* , water temp 195* . 70-80LOD makes me feel Fast! LOL . Could not get over 47.4 mpg though ( T'ja! bummer huh ?) .Switched back to 'my' 50-60 LOD pulse ,same speeds/IAT/WT and 57.8 popped out !
Tried again for the p.m. drive except 45 mph minimum speed because of traffic ended up with 43.1 mpg . Switched to the lower LOD for a 52.5 mpg finish. It's typical the p.m. drive is a little lower but for this car very light accel is the ticket . I will be making some more tries at this - it may just need the technique tweaked a bit .
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