08-20-2012, 03:18 AM
|
#1 (permalink)
|
EcoModding Lurker
Join Date: Aug 2012
Location: Mexico
Posts: 4
Thanks: 0
Thanked 0 Times in 0 Posts
|
Pulse & Glide vs maintaining constant speed
Hello everyone, this is my first post.
I own a 2010 1.8L AT Chevy Cruze.
I'm new to hyper-milling so i wanted to know what would be more efficient?
a) Accelerating to say 60 mph and gliding to 45 or 50 mph without shifting to Neutral (i don't want to wear out the transmission)
OR
b) Maintaining a constant speed of 60 mph
Thanks
|
|
|
Today
|
|
|
Other popular topics in this forum...
|
|
|
08-20-2012, 04:55 AM
|
#2 (permalink)
|
Scandinavian creature
Join Date: Jun 2012
Location: Finland
Posts: 146
Thanks: 4
Thanked 27 Times in 22 Posts
|
Quote:
Originally Posted by Mr_cracker
a) Accelerating to say 60 mph and gliding to 45 or 50 mph without shifting to Neutral (i don't want to wear out the transmission)
|
You dont need to shift to neutral, use clutch fully depressed to run in neutral
|
|
|
08-20-2012, 05:15 AM
|
#3 (permalink)
|
Master EcoModder
Join Date: Jan 2012
Location: United States
Posts: 1,756
Thanks: 104
Thanked 407 Times in 312 Posts
|
Quote:
Originally Posted by Quezacotl
You dont need to shift to neutral, use clutch fully depressed to run in neutral
|
Good luck pressing the clutch in on an automatic. I hear it's pretty hard.
|
|
|
08-20-2012, 08:03 AM
|
#4 (permalink)
|
Master EcoModder
Join Date: Jul 2010
Location: Belgium
Posts: 4,683
Thanks: 178
Thanked 652 Times in 516 Posts
|
Welcome to ecomodder.
Quote:
Originally Posted by Mr_cracker
I'm new to hyper-milling so i wanted to know what would be more efficient?
b) Maintaining a constant speed of 60 mph
|
If you don't want to shift into neutral, the constant speed is most likely better.
That is, if the transmission doesn't have a coasting feature built in.
__________________
Strayed to the Dark Diesel Side
|
|
|
08-20-2012, 08:49 AM
|
#5 (permalink)
|
Cyborg ECU
Join Date: Mar 2011
Location: Coastal Southern California
Posts: 6,299
Thanks: 2,373
Thanked 2,172 Times in 1,469 Posts
|
I think pulse and glide with an AT is really tricky, especially without an engine load readout. The car will want to switch gears when you try for an 80% load pulse, no? What I do with an AT is steady-state cruising. I only use neutral when cresting hills, because being in gear would slow the car excessively. I do a lot of engine braking, shifting to a higher gear if the selector allows it so that I can get full advantage of the deceleration fuel cut-off mode.
__________________
See my car's mod & maintenance thread and my electric bicycle's thread for ongoing projects. I will rebuild Black and Green over decades as parts die, until it becomes a different car of roughly the same shape and color. My minimum fuel economy goal is 55 mpg while averaging posted speed limits. I generally top 60 mpg. See also my Honda manual transmission specs thread.
Last edited by California98Civic; 08-20-2012 at 01:41 PM..
|
|
|
08-20-2012, 11:13 AM
|
#6 (permalink)
|
Hydrogen > EV
Join Date: Apr 2012
Location: NW Ohio, United States
Posts: 2,025
Thanks: 994
Thanked 402 Times in 285 Posts
|
When I drive my wifes automatic suv, I usually coast in gear at hills, going down I accelerate, up I use little to no throttle. I know some people exercise the right to drive as slow as they want, but out here people are crazy. So I let myself drop to the speed limit, or a few under, and then just mainain until the next hill. speeding, I speed as much as possible without getting a ticket, so when I come to a hill, I have room to drop.
In older cars, it was way more efficient to coast in nuetral than in gear, but it seems that is not exactly 100% confirmed anymore.
Not getting into a heated debate, but now a days autos typically are rated higher than standards, so surely there are improvements or changes going on.
I can't help but wonder what M C thinks when he says "I Have an auto trans, help me" amd the first response is "press the clutch" lol
|
|
|
08-20-2012, 01:59 PM
|
#7 (permalink)
|
EcoModding Lurker
Join Date: Aug 2012
Location: Mexico
Posts: 4
Thanks: 0
Thanked 0 Times in 0 Posts
|
Quote:
Originally Posted by euromodder
If you don't want to shift into neutral, the constant speed is most likely better.
That is, if the transmission doesn't have a coasting feature built in.
|
There's no ECO button on the dash if that's what you are referring to; but i have noticed the transmission always tries to be in the highest gear possible, if i can manage to pulse & glide without downshifting would it be worth it?
|
|
|
08-20-2012, 02:03 PM
|
#8 (permalink)
|
EcoModding Lurker
Join Date: Aug 2012
Location: Mexico
Posts: 4
Thanks: 0
Thanked 0 Times in 0 Posts
|
Quote:
Originally Posted by California98Civic
I think pulse and glide with an AT is really tricky, especially without an engine load readout. The car will want to switch gears when you try for an 80% load pulse, no?
|
I haven't tried it yet, but if i manage to stay in the highest gear while pulsing & gliding would it be worth it? or am i just better off maintaining a constant speed?
|
|
|
08-20-2012, 02:10 PM
|
#9 (permalink)
|
Cyborg ECU
Join Date: Mar 2011
Location: Coastal Southern California
Posts: 6,299
Thanks: 2,373
Thanked 2,172 Times in 1,469 Posts
|
Quote:
Originally Posted by Mr_cracker
if i can manage to pulse & glide without downshifting would it be worth it?
|
Maybe, but maybe not. The best approach is not to take anyone's word for it but rather to test. Get an UltraGauge or a ScanGauge that will show you real time data on engine load as you accelerate, do some ABA test, and find out. You will possibly teach something to EM's users. The UltraGauge is pretty cheap (70$) and it will pay for itself soon in showing you the benefit of all sorts of techniques.
__________________
See my car's mod & maintenance thread and my electric bicycle's thread for ongoing projects. I will rebuild Black and Green over decades as parts die, until it becomes a different car of roughly the same shape and color. My minimum fuel economy goal is 55 mpg while averaging posted speed limits. I generally top 60 mpg. See also my Honda manual transmission specs thread.
|
|
|
The Following User Says Thank You to California98Civic For This Useful Post:
|
|
08-20-2012, 02:20 PM
|
#10 (permalink)
|
Master EcoModder
Join Date: Dec 2008
Location: Southern WI
Posts: 829
Thanks: 101
Thanked 563 Times in 191 Posts
|
Honda Insight Example
Hi,
I have a 2000 MT Honda Insight, and it's no contest on which method gives better mileage, with the following conditions:
Use this technique only on backroads
Average speed is 35 mph or less
Ambient outside temp is 90F or above
No wind, and flat roads
The Honda engine has lean burn capability at low throttle settings
Straight-line driving: max mpg is 120 or so, at 35 mph
P&G; 35 to 15 mph: max mpg is over 150 (pegs display)
Universities use this same P&G method to achieve mpg readings of over 2000 and higher. Slow speeds and lot's of engine off coasting.
Hope this helps, Jim.
|
|
|
|