Go Back   EcoModder Forum > EcoModding > General Efficiency Discussion
Register Now
 Register Now
 

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 08-31-2009, 11:04 AM   #31 (permalink)
Batman Junior
 
MetroMPG's Avatar
 
Join Date: Nov 2007
Location: 1000 Islands, Ontario, Canada
Posts: 20,957

Blackfly - '98 Geo Metro
Team Metro
Last 3: 70.09 mpg (US)

MPGiata - '90 Mazda Miata
Last 3: 51.27 mpg (US)

Winter beater Metro - '00 Chevrolet Metro
90 day: 73.57 mpg (US)
Thanks: 2,773
Thanked 5,641 Times in 2,907 Posts
The ScanGauge readings weren't verified against filling the gas tank of the Vette - that's what I mean by uncalibrated. So yes, there's the possibility the MPG figures aren't exact... but it's unlikely they're out by more than a few percent.

My experience with the SG (comparing with "zero offsets" to filling the tank in several vehicles) is that it's not usually far off for "normal" driving, like the kind done for this test.

Quote:
I don't have or use a scanguage so maybe I just don't understand how it interacts with the car.
The ScanGauge calculates fuel use indirectly: it determines it based on air consumption, assuming a stoichiometric air/fuel ratio for a warmed up vehicle in closed loop operation (such as for this test).

__________________
Latest mods test: 15 mods = 15% MPG improvement: A-B test, 2007 Honda Civic 1.8L, 5-speed
Ecodriving test:
Manual vs. automatic transmission MPG showdown: Nissan Micra 1.6L



EcoModder
has launched a forum for the efficient new Mitsubishi Mirage
www.MetroMPG.com - fuel efficiency info for Geo Metro owners
www.ForkenSwift.com - electric car conversion on a beer budget
  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 08-31-2009, 11:20 AM   #32 (permalink)
Hypermiler
 
PaleMelanesian's Avatar
 
Join Date: Dec 2007
Location: Texas
Posts: 2,300

PaleCivic (retired) - '96 Honda Civic DX Sedan
90 day: 69.2 mpg (US)

PaleFit - '09 Honda Fit Sport
Team Honda
Wagons
90 day: 53.44 mpg (US)
Thanks: 574
Thanked 409 Times in 269 Posts
In my experience, the Scangauge tends to be slightly optimistic, but only by a small margin, like 3%. Whatever the offset is, it's a percentage and not a constant value. The curve on the chart will not change with calibration, just the scale on the Y axis would change. The most efficient speed will still be 30 kph / 37 mph, it just might be 36 instead of 36.5 mpg.
__________________



11-mile commute: 100 mpg - - - Tank: 90.2 mpg / 1191 miles
  Reply With Quote
The Following User Says Thank You to PaleMelanesian For This Useful Post:
MetroMPG (10-27-2009)
Old 08-31-2009, 05:54 PM   #33 (permalink)
Master EcoModder
 
Join Date: Nov 2008
Location: Madison AL
Posts: 1,123

The Geo - '93 Geo Metro
Team Metro
90 day: 45.16 mpg (US)
Thanks: 30
Thanked 40 Times in 37 Posts
Someone asked did it have cylinder de-activation earlier, I don't think it does. Are the Vett's still fiberglass?
  Reply With Quote
Old 09-01-2009, 09:12 AM   #34 (permalink)
Hypermiler
 
PaleMelanesian's Avatar
 
Join Date: Dec 2007
Location: Texas
Posts: 2,300

PaleCivic (retired) - '96 Honda Civic DX Sedan
90 day: 69.2 mpg (US)

PaleFit - '09 Honda Fit Sport
Team Honda
Wagons
90 day: 53.44 mpg (US)
Thanks: 574
Thanked 409 Times in 269 Posts
I believe the standard ones are, but the Z06 is carbon fiber.
__________________



11-mile commute: 100 mpg - - - Tank: 90.2 mpg / 1191 miles
  Reply With Quote
Old 09-01-2009, 11:01 AM   #35 (permalink)
...beats walking...
 
Join Date: Jul 2009
Location: .
Posts: 6,191
Thanks: 179
Thanked 1,521 Times in 1,122 Posts
Quote:
Originally Posted by Mustang Dave View Post
In my experience, the best FE is at the lowest speed in your top gear.
...exactly! That's the condition where you get SLOWEST engine speed for the MOST throttle opening (without being WOT), ie: least amount of "pumping" loss for the hp generated.

...anybody remember the Oldsmoble "Turnpike" cruisers?
  Reply With Quote
Old 09-01-2009, 02:20 PM   #36 (permalink)
...beats walking...
 
Join Date: Jul 2009
Location: .
Posts: 6,191
Thanks: 179
Thanked 1,521 Times in 1,122 Posts
Quote:
Originally Posted by MetroMPG View Post
I've updated Post 1 at the top of this thread with this graph of the results, plus methodology & raw numbers.

...if my number-crunching is correct (6th=0.57:1), the missing rpms would be 1,093 rpm at 50 mph and 1,230 rpm at 56 mph...sound about right?

Last edited by gone-ot; 09-01-2009 at 02:33 PM.. Reason: corrected KM/H to MPH
  Reply With Quote
Old 09-01-2009, 02:26 PM   #37 (permalink)
Hypermiler
 
PaleMelanesian's Avatar
 
Join Date: Dec 2007
Location: Texas
Posts: 2,300

PaleCivic (retired) - '96 Honda Civic DX Sedan
90 day: 69.2 mpg (US)

PaleFit - '09 Honda Fit Sport
Team Honda
Wagons
90 day: 53.44 mpg (US)
Thanks: 574
Thanked 409 Times in 269 Posts
I get 1080 and 1215, but it's close.
__________________



11-mile commute: 100 mpg - - - Tank: 90.2 mpg / 1191 miles
  Reply With Quote
Old 09-02-2009, 12:10 AM   #38 (permalink)
Batman Junior
 
MetroMPG's Avatar
 
Join Date: Nov 2007
Location: 1000 Islands, Ontario, Canada
Posts: 20,957

Blackfly - '98 Geo Metro
Team Metro
Last 3: 70.09 mpg (US)

MPGiata - '90 Mazda Miata
Last 3: 51.27 mpg (US)

Winter beater Metro - '00 Chevrolet Metro
90 day: 73.57 mpg (US)
Thanks: 2,773
Thanked 5,641 Times in 2,907 Posts
Quote:
Originally Posted by MadisonMPG View Post
Someone asked did it have cylinder de-activation earlier, I don't think it does.
You're right - it does not.

Quote:
Are the Vett's still fiberglass?
Yes. The Z06 has some carbon fiber (the owner mentioned the liners inside the wheel wells as an example, and a balsa wood/carbon fiber composite floor). Also the frame is aluminum, vs. steel in the regular model.
__________________
Latest mods test: 15 mods = 15% MPG improvement: A-B test, 2007 Honda Civic 1.8L, 5-speed
Ecodriving test:
Manual vs. automatic transmission MPG showdown: Nissan Micra 1.6L



EcoModder
has launched a forum for the efficient new Mitsubishi Mirage
www.MetroMPG.com - fuel efficiency info for Geo Metro owners
www.ForkenSwift.com - electric car conversion on a beer budget
  Reply With Quote
Old 09-02-2009, 09:48 PM   #39 (permalink)
Master EcoModder
 
Big Dave's Avatar
 
Join Date: Jan 2008
Location: Steppes of Central Indiana
Posts: 1,304

The Red Baron - '00 Ford F-350 XLT
90 day: 27.99 mpg (US)

Impala Phase Zero - '96 Chevrolet Impala SS
90 day: 21.03 mpg (US)
Thanks: 0
Thanked 176 Times in 120 Posts
I think this data vindicates my approach of low RPM = max MPG, even for gasoline engines. The Z06 with its LS7 engine has such mammoth torque as to allow operation at vividly low RPMs. The same principle works for a high-revving Honda engine, just the cutoff for lugging occurs at a higher RPM.

As you can see from this, the Tremec 6060 transmission used in the Z06 has a 0.63:1 top overdrive ratio, but a 0.5:1 ratio could be had if MPG were to be emphasized.

Tremec TR-6060 transmission - Wikipedia, the free encyclopedia

BTW, I am seriously looking at getting the Challenger version to replace the ZF6-650 in my truck. That with a couple of aero tweaks might get me over 30 MPG in my mixed-driving circuit. It has an optimal ratio spread and its 600 ft-lb rating is A-OK for my Powerstroke which has been dyno-tested to deliver 560 ft-lb max torque. Having a 1.54:1 overall reduction should give spectacular results.

Too bad the GM 4.5 liter diesel is dead. Given the LS7 in this test is operating way below its peak volumetric efficiency, it is incurring huge pumping losses for not much power. The diesel suffers no such loss. It would be interesting to see what a 4.5 could have done if fed the 70 cetane Fischer-Tropsch fuel the Audi & Peugeot prototype racers use.
__________________
2000 Ford F-350 SC 4x2 6 Speed Manual
4" Slam
3.08:1 gears and Gear Vendor Overdrive
Rubber Conveyor Belt Air Dam
  Reply With Quote
Old 09-03-2009, 09:55 AM   #40 (permalink)
Hypermiler
 
PaleMelanesian's Avatar
 
Join Date: Dec 2007
Location: Texas
Posts: 2,300

PaleCivic (retired) - '96 Honda Civic DX Sedan
90 day: 69.2 mpg (US)

PaleFit - '09 Honda Fit Sport
Team Honda
Wagons
90 day: 53.44 mpg (US)
Thanks: 574
Thanked 409 Times in 269 Posts
Quote:
Originally Posted by Big Dave View Post
I think this data vindicates my approach of low RPM = max MPG, even for gasoline engines. The Z06 with its LS7 engine has such mammoth torque as to allow operation at vividly low RPMs. The same principle works for a high-revving Honda engine, just the cutoff for lugging occurs at a higher RPM.
I concur. I have no tachometer, so I finally paid more attention to my rpm on the Scangauge this morning. I can gain speed from about 800 rpm with my little Honda. I typically run P&G cycles in the 1000-1500 rpm range. That's lower than I thought I was doing.

__________________



11-mile commute: 100 mpg - - - Tank: 90.2 mpg / 1191 miles
  Reply With Quote
Reply  Post New Thread


Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Tested: speed vs MPG - 2006 Toyota Corolla automatic MetroMPG General Efficiency Discussion 28 05-11-2016 10:00 PM
How to get instant fuel consumption from Megasquirt TELVM Instrumentation 11 08-29-2011 02:47 PM



Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2019, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com