80+ Mpg

Trips from Home to Work on a Sunday on the interstate. Set cruise at 50 indicated (~48 actual per VagCom) once on the interstate which is ~2 miles from home, very little wind on either trip ~70F and very humid. Engine started cold and it was raining on the way to work. The engine was mostly warm and it was not raining (dry roads) on the way home. I changed the max reported MPG from 100 to 200 on the trip home as I was spending a lot of time with it pegged out at 100 on the trip there which may also be a contributing factor to the return trip showing higher MPG

Screen Shots of VagScope

Overall MPG is 44.8 Miles/(0.3062 + 0.2478) gallons for 80.86 MPG with an average speed of 43.25 MPG.

I don’t know how accurate the VagScope thing is, but I checked on my normal commute to/from work before and it returned low 60’s which is what I typically get using the trip miles and fill up method so it’s not way off. I’m still amazed at how much the instant MPG can change with a small change in throttle position (20’s to 50’s) and a very small change in acceleration performance.

I know this does not have much statistical significance - would need a few tanks full to do that. Just a see what I could do on a slow easy drive and to check out the cool VagComScope MPG Tool.

It’s going to be a while before I get a good MPG tank again, this partial one should be good (60’s), have a road trip with the trailer and family next weekend and Labor day weekend. Hoping for mid 40’s with the trailer.

Potentially very interesting, but the usual warnings about drawing too much info from such a small sample apply. If you can keep it up over a couple tankfuls, though...

Anytime that you'll just be going to work and back with no sidetrips where you can duplicate the conditions for a few weeks at a time?

Mike

Mike_M said:

...Anytime that you'll just be going to work and back with no sidetrips where you can duplicate the conditions for a few weeks at a time...

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No - My usual route to work is 17 miles each way with 19 opportunities to stop or turn of which I end up stopping at ~1/2 of them per trip. I know this route well and have it reasonably well "mastered" in terms of where I can coast, which lights I'll make etc (that's how I get 60's in this type of driving) During the week the interstate is way to stop and go bumper to bumper traffic to make any reasonable attempt at good MPG's. Sunday at noon there was little traffic for me to be an impedance to and I was able to make the trip un-interrupted in terms of slowing down/speeding up.

I understand that it's a very small sample and not verified by refilling or anything, but neat none the less.

I was thinking of making some mileage runs from my usual fueling stop, go out 50 miles toward Madison, turn around and come back for a 100 mile total, re-fill, try it again at a different speed, etc to quantify the effects of speed on MPG in my car, but I'm not quite that bored, it's a waste of fuel and probably won't yield great results test to test considering measurement errors on <2 gallons of fuel.

I'll be taking more road trips alone in the future (250 miles each way) and will mabe try one at 50 or 55 indicated when I'm not in a big hurry - see if I can crack the 80 mark over some significant distance

Fix_Until_Broke said:

No - My usual route to work is 17 miles each way with 19 opportunities to stop or turn of which I end up stopping at ~1/2 of them per trip.

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Darnit.

I'll be taking more road trips alone in the future (250 miles each way) and will mabe try one at 50 or 55 indicated when I'm not in a big hurry - see if I can crack the 80 mark over some significant distance

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Very cool...I'd love to see the results over even half or 1/3 of a tankful.

Mike

Sorry but I call BS on this one.

1. Thats what 20mpg more than any other TDI member has ever posted. and all because you have created a vagcom scope?

2. That would put you in the 1200mpg tank club

3. The 1800lbs Honda Insight takes alot of effort to break 80mpg. Yet your able to do this in a 3000lbs car?


But the vagscope MPG tool is pretty neat. Just need to see how accurate it really is.

what are you talking about, 03 01 TDI? Ernie is getting pretty close to 80, if he hasn't broken into that range before. He is predicting 80's on the way to the tdifest.

I've got an 04, which puts me at a disadvantage and I'm getting closer and closer to 70.

He said he was traveling at 48mph, I would say that should put him at getting close to 80mpg. I've no problem with that. If you do... you need to slow down.

03_01_TDI said:

Sorry but I call BS on this one.

1. Thats what 20mpg more than any other TDI member has ever posted. and all because you have created a vagcom scope?

2. That would put you in the 1200mpg tank club

3. The 1800lbs Honda Insight takes alot of effort to break 80mpg. Yet your able to do this in a 3000lbs car?


But the vagscope MPG tool is pretty neat. Just need to see how accurate it really is.

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1) No, Its three mpg LESS than I have posted. In the 2003 Tour de Sol I achieved 83 mpg on B100 biodiesel in a 1996 Passat sedan over a 250 mile route. In the 2005 Tour de Sol two other drivers achieved 77 mpg in my 1996 Passat wagon on a 500 mile route.

2) Twelve hundred miles per tank means I'm leaking fuel. I've reached 1400 miles 2 or 3 times (yes, I've lost count).

3) Brush up on physics. Weight has negligible effect on constant speed fuel economy.

Energydemanded = Powerdemanded*time
={((mvehicle+mpayload)*g*fR*sin(atan(gradientroad))+(ei*mvehicle+mpayload)*ax+0.5*rho*Cd*A*V^2)*V}*t

where:
mvehicle = obvious; unloaded curb mass
mpayload = obvious (passengers, cargo, etc.)
g = acceleration due to gravity (i.e. 9.81 m/s^2)
fR = Rolling resistance coefficient
gradientroad = road gradient in percent, expressed as decimal (e.g. 10% = 0.1)
ei = mass factor due to inertia
ax = longitudinal vehicle acceleration (e.g. m/s^2)
rho = ambient air density (e.g. 1.2 kg/m^3 @ STP)
Cd = aerodynamic drag coefficient
A = vehicle frontal area (e.g. m^2)
V = vehicle velocity (e.g. m/s)
t = elapsed time (e.g. seconds)

Has that MPG utility been updated at all since the stone ages when I downloaded my copy? My "Max" is limited to 60mpg.

I don't like upper limits placed on my fuel economy.

Variant TDI said:

Has that MPG utility been updated at all since the stone ages when I downloaded my copy? My "Max" is limited to 60mpg.

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I'm not sure which version you have - but I set my MAX to 200 MPG. Right click on the upper left most corner of the window and select preferences - it's in there.

I'll try that... I love that little Applet. It really teaches you how to drive. I always feel bad when I have to goose it.

does this work on Gas motored VWs? like my VR6? wouldnt mind playing with it..

Well, then I stand corrected and amazed.

I might end up running over to the cities in two weeks. Now if I could convince my wife to let me drive 50mph all the way I could tell you, but she complains when I run 60mph on 29 the whole way

Brock - I've got some ear muffs to drown out the complaining

Since people are willing to do this how about someone doing a few round trips at 1900 rpm in 4th gear and compare to a few round trips at ~1600 in 5th gear.

1600 in 5th gear? No, thanks. I don't like upper limits placed on my fuel economy.

Growler said:

does this work on Gas motored VWs? like my VR6? wouldnt mind playing with it..

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It requires a VAG field that outputs liters/hour consumption data, and I don't know if the gasser has it.

My Mk3 VR has a MPG guage, which has proven itself to be extremely accurate, but I don't remember seeing a Liters/Hour field in VAG-COM. I think it gets it's consumption data from the injector duty cycle, which wouldn't work with this little applet.


03_01_TDI... I found that just by having the scope "big brothering" me... I was more conscious of my driving habits, and how un-smooth I was. The tank I burned with the scope attached had a 4 mpg gain. I don't need anymore proof that the biggest mpg helper is training the right foot.

Variant TDI said:

03_01_TDI... I found that just by having the scope "big brothering" me... I was more conscious of my driving habits, and how un-smooth I was. The tank I burned with the scope attached had a 4 mpg gain. I don't need anymore proof that the biggest mpg helper is training the right foot.

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I've said this for years now. Posted it several times on this website. A proper IMPG (instant miles per gallon) display is the best MPG improver a car can have. Having owned a Honda Insight with this display
http://www.insightcentral.net/_images/eninstmpg.jpg
http://www.insightcentral.net/_images/eninstinst.jpg

At the lower portion of the display, a bar graph shows the instantaneous fuel economy, which changes in real time based on the amount of fuel that the fuel injectors are currently delivering, and based on the current speed.

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Being able to see that the extra 1mm of pedal pressure just caused me to loose xxxmpgs then I would wait till I peaked the top of a hill to resume getting to speed. Or I could watch my speed and pedal pressure as I climbed a hill to keep above a set MPG.

If VW was to put in such a system then my guess is 50mpg tanks would be very common-- for those who drive fast. Plus those who want to be kings -- easy 60+ mpg.

The gauge was good to see mod changes. For example. Installed a tub to get air from the back side of the engine (warm air intake) and see an improvement in MPG. Or see a loss in MPG and know that you've lost some air pressure. Etc etc. I really miss that little gauge. But now that I have several thousands dollars in go-faster mods-- I am glad I don't

I wish our cruise controls had a setting for maintaining a set impg or more. It would be nice to set the cruise on 60 mph and tell it not to go below 40 impg while doing it! (impg = instantaneous miles per gallon)

I always thought those gauges should be mandatory on all new vehicles. I guarantee people would slow down big time when they see what it does to economy.

Or have more wrecks. Looking at the MPG display, while talking on the phone, and putting on lipstick. lol lol

As I've said the Honda has a great instane MPG display. But even so it takes some time off of the road to look at the gauges. Never once had a close call becuase of looking at the gauge. However it was a hassle. thus my wife couldn't do it and she always screwed up that tanks MPG.

Also alot of cars do have IMPG and trip MPG. But they are so bruttle to look at that you'd never drive the car! Having just bought an Benz V8 suv its terrible to glance up and see single digits on the MPG 8mpg. Then as you get up to speed you try soo hard to stay above 20mpg..... So I just try and not even look at it. Most GM vehicules have the same type of displays.

Lightflyer1 said:

I wish our cruise controls had a setting for maintaining a set impg or more. It would be nice to set the cruise on 60 mph and tell it not to go below 40 impg while doing it! (impg = instantaneous miles per gallon)

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They could improve the efficiency of the cruise control algorithm by allowing it to "droop" some when the car encounters hills.... instead of maintaining the set speed up a hill, allow the engine speed to droop back a couple of mph. Most cruise controls in tractor/trailers are set up this way as a way to improve fuel economy.

moondawg

moondawg said:

They could improve the efficiency of the cruise control algorithm by allowing it to "droop" some when the car encounters hills.... instead of maintaining the set speed up a hill, allow the engine speed to droop back a couple of mph. Most cruise controls in tractor/trailers are set up this way as a way to improve fuel economy.

moondawg

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I was actually considering a mod (would take considerable work) involving installing a switch that would transfer control of the "throttle" from the "go-pedal" potentiometer to a dash-mounted one.

Then I could dial in a set amount of "throttle" and allow the car to slow a bit on the uphills and gather speed a bit on the downhills.

Either that, or some sort of more complex system where it something (probably a small computer) would sense the resistance from the pedal potentiometer at the point at which you hit "set" and maintain that...essentially a 2nd, parallel cruise control system that operates entirely on maintaining "throttle %" rather than speed.

I wonder if it's something Jeff could manage as a custom RC add-on? I don't know what language the ECU's code is written in, but it should only take changing the cruise control code's references to one parameter (from "MPH" to "throttle %"). Hmmm...

Mike

This really isn't far fetched at all. I have a very similar drive to work as well. 17 miles, with lots of stops. I happen to drive at non-peak driving hours most of the time so I am able to stay in the right lane and not get run over as I go for max mpg's on my drive.

I couldn't agree more that before I bought my Scanguage my average mpg was in the 46-48 mpg on a tank. Since adding it I am now at a 52-54 mpg average per tank. I find the info provided essential for good mpg.

Now something that I have to note from my drive is that my mpg varies greatly depending on the direction I am going on my route. Going from home to work my average is right around 54-56 mpg, from my work to home drive my average is right around 72-74 mpg. My max according the the mpg average is 79.4 mpg(I timed all the lights but one and didn't have to slow dramatically for any of them to get through). It is the hills and grades I have to drive that make the difference. On my way into work for about 14 miles of the trip I am generally in the upper 60 mpg(flirting with 70 mpg many times) range until I have to start up a mountain road that climbs about 3000 feet elevation and this kills my mileage. The drive home though I am in fuel overrun that first 3 miles down the mountain and my highest recorded mpg at the bottom of the mountain was 618 mpg, but this goes away as soon as you touch that accelerator. From there I am just trying to stay out of the throttle as much as possible and try to keep my average from falling too fast.

Another thing I noted on my drive home it is a gradual up hill grade and my mpg average is falling on the asphalt, but as soon as I transition to the concrete pavement the mpg stabilizes.

What kills my mpg tank average is those odds and ends trips that I don't have the routes all planned out, and where I don't have control over the time of day that affects my traffic that I have to deal with. I try to minimize these so as to limit my tank average impact, but it still hurts me a 2-3 mpg per tank.

My speed when moving is 45 mph indicated on the speedo. So I know depending on the direction, grade, speed, lights, and road surface I am pretty sure I could hit 80 mpg for a modest duration trip. Getting that average for a tank... Well I can wish can't I?

I would say do these same runs again calculating each way seperately and see what you come up with. You might be experiencing something similar to what I have with my drive.

Longsnowsm

I was curious whether anyone has gotten the vagcom mpg tool to work with newer versions of Vag-Com. I have version 607.2 and all I see when I get the scope tool up is the interface with no data. Also noticed the requisite measuring blocks have changed, assuming advanced meas. blocks is not used. Shame to see such a cool tool fall to neglect...or maybe I am doing something wrong.

My version is 504.1-UD - I didn't realize there have been so many updates in the year I've owned it.

Maybe I'll update and see if it works, but I wish someone else would try it first - I really like this tool.

Make sure you are using groups 15, 18 & 10
I don't think that you need to use advanced measuring blocks, but I don't remember exactly.

I tried 15,18,10 but that doesn't give a vehicle speed reading anywhere on my set up (off the top of my head I don't rememeber exactly what it did give though). Also tried doing advanced measuring blocks to get a vehicle speed and fuel consumption up and running but no luck either. Just curious whether other folks have this working and I am doing something wrong or maybe it hasn't been updated for latest vag-com....