Approaching hills, technique? - Page 4 - Fuelly Forums

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

Reply
 
Thread Tools Display Modes
 
Old 10-26-2015, 08:39 PM   #31
Site Team / Moderator
 
Jay2TheRescue's Avatar
 
Join Date: Sep 2008
Location: Northern Virginia
Posts: 4,657
Country: United States
Location: Northern Virginia
Arrow

Quote:
Originally Posted by Quadrunner View Post
I always think of it this way. If you ever feel your engine start to bog down a little its running richer, so there is a little gas that is not getting used to its fullest potential. That is not a fact. That is how I justify my actions. I get my best mpg on hills because I don't use my cruise control. I usually feather the throttle the entire time. I keep the engine running lean as I can while still slightly accelerating downhill, so I can slightly decelerate going up the next hill. I usually maintain speed at the base of a hill and then the more I get up the more I'll let off to keep the engine running lean as the rpm's drop. By the time I get to the top my gas petal is at or around its highest point in the cycle and I repeat. Works good for me!
You just about perfectly described the "Driving with load" technique, and it is VERY effective on hills.
Quote:
Originally Posted by Quadrunner View Post
I never understood the point of coasting in neutral unless maybe its on your final hill or two before a stop. Your engine is still running and you still have drivetrain friction since the drive wheels are connected to the transmission all the time. It seems like your paying for a slight increase in mpg with drivetrain stress from the extra shifting from neutral to high gear. I guess I like my car too much. There is also the consideration here that the more your speed fluctuates, the more you will lose to air drag at the bottom of the hill. If you feel your car begin to near terminal velocity in Georgia overdrive, its a good indication you could be doing a little better. Just my humble opinion. I don't have the computers to back it up, and my newest cars have historically been about 15 years old.
Vehicles with electronic fuel injection will shut down the injectors (Fuel Cut) and engine brake if left in gear. This is fine on steep hills, but on more gradual hills, you can either idle the engine and coast in Neutral, or leave it in drive and hold your foot on the throttle. Personally, I use all of the techniques you describe (Driving With Load, Neutral Glide, and Fuel Cut) depending on my speed, incline of hill, traffic, and whether I intend to speed up, or slow down.
__________________

__________________






Jay2TheRescue is offline   Reply With Quote
Old 10-27-2015, 12:08 AM   #32
Registered Member
 
Join Date: Aug 2009
Posts: 2,483
Country: United Kingdom
Location: Mid Wales
Thanks for the input. Recently I have been trying the exact technique you described, being gentle, and not accelerating hard but progressively. I try to keep the turbo just on boost, not so much that it's using too much fuel, but just enough to pull me up the hill. I still loose speed, that's the only thing as it's obviously a small car and some of these hills are pretty big, the only way to avoid loosing speed is to apply maximum throttle, but then that's a huge waste of fuel.
__________________

__________________

Please subscribe to my YouTube channel
Draigflag is offline   Reply With Quote
Old 10-27-2015, 06:17 PM   #33
Site Team / Moderator
 
Jay2TheRescue's Avatar
 
Join Date: Sep 2008
Location: Northern Virginia
Posts: 4,657
Country: United States
Location: Northern Virginia
If you're doing DWL properly, you will lose speed going up hills.
__________________






Jay2TheRescue is offline   Reply With Quote
Old 10-28-2015, 10:13 AM   #34
Registered Member
 
Join Date: Aug 2009
Posts: 2,483
Country: United Kingdom
Location: Mid Wales
So is it better be gentle and sacrifice a little speed when ascending a steep hill would you say?
__________________

Please subscribe to my YouTube channel
Draigflag is offline   Reply With Quote
Old 10-28-2015, 04:51 PM   #35
Site Team / Moderator
 
Jay2TheRescue's Avatar
 
Join Date: Sep 2008
Location: Northern Virginia
Posts: 4,657
Country: United States
Location: Northern Virginia
Arrow

Yes. let it bleed off speed, but just make sure you stay going fast enough to keep it in high gear. If you slow down enough for it to downshift, then you're using more fuel.
__________________






Jay2TheRescue is offline   Reply With Quote
Old 01-18-2016, 10:55 AM   #36
Registered Member
 
Join Date: Jan 2014
Posts: 104
Country: United States
DraigFlag, I read somewhere that your best MPG tactic when approaching a grade is to maintain the same gas pedal push. Simply allow the car to slow down naturally on the upside of the grade.

I suppose, for the convenience of cars behind you, you can accelerate BEFORE the hill to maintain a reasonable amount of speed on the upside of the grade.

In other words, depressing the gas pedal on the upside of the hill IS the worst thing you could do to to MPG.
ChewChewTrain is offline   Reply With Quote
Old 01-18-2016, 10:59 AM   #37
Registered Member
 
Join Date: Aug 2009
Posts: 2,483
Country: United Kingdom
Location: Mid Wales
I tried that, and the hills are often too long and I gradually loose too much speed. Once I reach about 45 Mph, the gsi (gear shift indicator) tells me to change into 4th. So now I'm changing into 4th and feathering the throttle more using higher revs instead. Not sure if it's any more or any less efficient yet.
__________________

__________________

Please subscribe to my YouTube channel
Draigflag is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Powered by vBadvanced CMPS v3.2.3


All times are GMT -8. The time now is 08:26 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.