Go Back   EcoModder Forum > EcoModding > Hypermiling / EcoDriver's Ed
Register Now
 Register Now
 

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 12-15-2009, 05:10 PM   #21 (permalink)
The PRC.
 
Join Date: Oct 2009
Location: Elsewhere.
Posts: 5,304
Thanks: 285
Thanked 536 Times in 384 Posts
Quote:
Originally Posted by dcb View Post
LOL, did my post make any sense?
Yeah, sort of. In between my original post and the edit is when yours appeared. I need to tap faster.

I see the graph. Mine is the ASZ version of that engine (130hp) but probably similar. Not sure about the full throttle thing though as that would surely just mean unburnt excess fuel (Diesel = fuel controlled) and in any case the turbo would kick in and I would be at 2500+ before I know it.

I shall experiment with the highest gear approach though, part throttle enough to maintain speed or bleed it off enough to get to the top and then coast down. I don't EOC as my steering and brakes don't work well with no engine.

EDIT : Reason for my post is I'm kind of living of the instant MPG reading and its painful watching it hit 25 or less when going uphill vs --- (i.e. infinity) when going down.

__________________
[I]So long and thanks for all the fish.[/I]

Last edited by Arragonis; 12-15-2009 at 05:16 PM.. Reason: More info
  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 12-15-2009, 05:15 PM   #22 (permalink)
dcb
needs more cowbell
 
dcb's Avatar
 
Join Date: Feb 2008
Location: ÿ
Posts: 5,038

pimp mobile - '81 suzuki gs 250 t
90 day: 96.29 mpg (US)

schnitzel - '01 Volkswagen Golf TDI
90 day: 53.56 mpg (US)
Thanks: 158
Thanked 269 Times in 212 Posts
there is less return on EOC for a diesel, but clutch/neutral coast will carry you farther than coasting in gear.

I don't have reason to believe full throttle on a small smart diesel = proportionately more unburnt fuel, otherwise my bsfc peak would not be sitting on the torque curve.
__________________
WINDMILLS DO NOT WORK THAT WAY!!!
  Reply With Quote
Old 12-15-2009, 05:32 PM   #23 (permalink)
Moderate your Moderation.
 
Join Date: Nov 2008
Location: Troy, Pa.
Posts: 8,919

Pasta - '96 Volkswagen Passat TDi
90 day: 45.22 mpg (US)
Thanks: 1,369
Thanked 430 Times in 353 Posts
As I learned it, lugging is defined as the point in the engine's power curve where it doesn't make enough power at full throttle to maintain your current vehicle speed. This would make the lug-point dynamic, not static.

I follow this rule, except at 80% throttle in gassers. (Unless they're GDI, then 100% is OK.)

I've never heard the definition regarding the use of carbs at all, and I find it unlikely, since diesels also suffer from lugging issues.
__________________
"¿ʞɐǝɹɟ ɐ ǝɹ,noʎ uǝɥʍ 'ʇı ʇ,usı 'ʎlǝuol s,ʇı"

  Reply With Quote
Old 12-15-2009, 06:52 PM   #24 (permalink)
Master EcoModder
 
Join Date: Jan 2008
Location: Victoria , Australia.
Posts: 499
Thanks: 20
Thanked 46 Times in 33 Posts
Quote:
Originally Posted by brucey View Post
The best way I've found (automatic transmission) is to have speed when you start the hill and bleed it off a bit as you climb the hill. Letting go of the gas completely JUST before the peak and coasting all the way back down.

This method is almost as good as a level straight.

Yep this is the same technique I use as well but I think the hills here are not as frequent or steep as those in West Virginia.

A "get momentum working for you" approach is the best option if the hill allows it but where it is along haul then drop into a lower gear earlier and maintain as much as you can.

Pete.
  Reply With Quote
Old 12-16-2009, 11:23 AM   #25 (permalink)
EcoModding Lurker
 
Join Date: Jan 2009
Location: Uk
Posts: 17
Thanks: 1
Thanked 1 Time in 1 Post
Quote:
Originally Posted by dcb View Post
But that is where I make the most power for a given amount of fuel on my tdi. Start gliding prior to the peak so that you glide crawl over the top and reduce need for braking as appropriate.
from ecomodders very own wiki (which anyone can edit/contribute to) Brake Specific Fuel Consumption (BSFC) Maps - EcoModder
I can believe that chart to be accurate for the VW 130Bhp engine. We too have a Skoda Vrs and I can feel the engine become more torquey and efficient in the range of 1,500-2,500 rpm. This is borne out by the instantanoius mpg reading climbing rapidly once 1,500 rpm is breached.

A standard rule of thumb used to be drive within the range of peak torque +1000rpm -500rpm for best efficiency. Under light load lower revs can be used without the engine bogging down. I'd be wary of running high loads at low revs in a diesel as that can create very high forces on the big ends and crank.

For hills I use the 'arrive a bit quicker and let speed bleed off slowly' technique.
In the Vrs one needs to be careful to not be in too high a gear under load, it seems to increase consumption.
  Reply With Quote
Old 12-17-2009, 03:07 AM   #26 (permalink)
The PRC.
 
Join Date: Oct 2009
Location: Elsewhere.
Posts: 5,304
Thanks: 285
Thanked 536 Times in 384 Posts
One other issue doing this in the UK is traffic volume, quite often people just don't like following someone driving with load or doing the rollercoaster. In my view they should just leave a long gap (I do this to break up jams often) but I'm usually in a minority.

I shall experiment further, there are plenty of hills to try.
__________________
[I]So long and thanks for all the fish.[/I]
  Reply With Quote
Old 12-17-2009, 08:35 AM   #27 (permalink)
Master EcoModder
 
Join Date: Sep 2009
Posts: 5,927
Thanks: 877
Thanked 2,024 Times in 1,304 Posts
Quote:
Originally Posted by Arragonis View Post
One other issue doing this in the UK is traffic volume, quite often people just don't like following someone driving with load or doing the rollercoaster. In my view they should just leave a long gap (I do this to break up jams often) but I'm usually in a minority.

I shall experiment further, there are plenty of hills to try.
The roller coaster is most efficient for the professional driver who makes a living hauling loads. Reducing fuel cost means money in their pocket.

On I95 between Richmond and Washington DC, the truckers will do the "roller coaster" with speeds ranging from 53 to 75 MPH in a 65 zone. Leaving stopping distance (3 stripes x 43 feet) between us is my favorite position on that road in heavy traffic. The road is 3 lanes each way, and if you get in the inner two lanes the aggressive drivers treat it like a NASCAR race, with separation distances measured in feet and passing proximity measured with a yardstick.

Instead of trying to impose my desire for better driving habits on others, I just pace myself behind the trucks, which generally stay in the right lane.
This also gives me an escape route to the right, where the shoulder is paved and as wide as either of the three lanes available for traffic.

The hills around Fredericksburg are of sufficient grade to allow coasting (in neutral-engine on) at speeds of 70+, and in some cases you even need to use DFCO to keep your speed down. While you may see only 25 MPG on the uphill section, on the same hill's downhill section the mileage can exceed 300 MPG.

Doing this achieved the highest single trip mileage I ever recorded in my VX, over 68 MPG, at an average speed on 64 MPH. May of 2008 when fuel cost here were approaching $4 per gallon. Two passengers and cargo with a total weight of about 500 pounds.

I prefer alternative routes to the above mentioned scenario, but at night, the greatest danger here is Deer running out in front of your car. A friend once hit a Deer and it came through the windshield of his van. They had to open the door to let the Deer out.

regards
Mech
  Reply With Quote
Old 12-17-2009, 05:45 PM   #28 (permalink)
The PRC.
 
Join Date: Oct 2009
Location: Elsewhere.
Posts: 5,304
Thanks: 285
Thanked 536 Times in 384 Posts
I agree - except being in Scotland most roads are 2 lanes only - so nowhere to hide and not be annoying.
__________________
[I]So long and thanks for all the fish.[/I]
  Reply With Quote
Old 12-17-2009, 06:40 PM   #29 (permalink)
dcb
needs more cowbell
 
dcb's Avatar
 
Join Date: Feb 2008
Location: ÿ
Posts: 5,038

pimp mobile - '81 suzuki gs 250 t
90 day: 96.29 mpg (US)

schnitzel - '01 Volkswagen Golf TDI
90 day: 53.56 mpg (US)
Thanks: 158
Thanked 269 Times in 212 Posts
ok, well in answer to the original question (and the title of this thread), it is as I described, load up the hill at bsfc peak and glide down and glide crawl over the top so you brake less.

Maybe we should change the thread title to "Hills (most efficient climbing technique for diesel / manual transmission after I put a whole bunch of conditions on it)"
__________________
WINDMILLS DO NOT WORK THAT WAY!!!
  Reply With Quote
Old 12-18-2009, 03:03 AM   #30 (permalink)
The PRC.
 
Join Date: Oct 2009
Location: Elsewhere.
Posts: 5,304
Thanks: 285
Thanked 536 Times in 384 Posts
Does it make a difference if I'm wearing glasses ?

__________________
[I]So long and thanks for all the fish.[/I]
  Reply With Quote
Reply  Post New Thread


Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Effect of gear oil viscosity on transmission efficiency (Metro owners take note) MetroMPG EcoModding Central 44 12-08-2014 11:22 PM
New CVT transmission electric-assist with electric assist Ptero Fossil Fuel Free 2 09-23-2010 10:41 PM
Tesla Roadster's 98% efficient transmission nominated for innovation award MetroMPG Fossil Fuel Free 20 12-20-2009 01:51 PM
Synthetic transmission fluid for a manual transmission? abcdpeterson General Efficiency Discussion 15 10-12-2009 08:56 AM
Choosing a Manual Transmission Fluid for my Mazda Protege 1337 EcoModding Central 5 03-20-2009 12:07 PM



Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com