rjp0627
Active member
I'm a little disappointed; I checked my fuel mileage the old fashion way by tracking the mileage and gallons used. Result was 43.7 mpg all highway driving. The car computer indicated 49.3. The real math does not lie.
Real Fuel Mileage
- Thread starter rjp0627
- Start date
dst5
Veteran Member
My last car a Sonata about the same size got 28 MPG @75MPH the Passat is over 50% more MPG. Also the 43.7 is over the EPA hwy est mileage. There is a parameter adjustment that will bring those numbers closer together.
skinnyb
Veteran Member
My MFD is always off sometimes significantly. I call it the lie-o-meter.
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Sent from my iPhone using Tapatalk
Joe_Meehan
Top Post Dawg
You seem to be doing OK. However, how about telling us how you are doing the measurements? What has the weather been like? How many fill ups have you done. How exactly are you measuring the MPG?
Unfortunate that your MFI got your hopes up. So far, my MFI has read low, sometimes by two to three MPG's.
Is your 43MPG lower than normal? What does the car usually return on this trip? Extended idling? Lots of grades? Snow or rain?
Is your 43MPG lower than normal? What does the car usually return on this trip? Extended idling? Lots of grades? Snow or rain?
tdiatlast
Top Post Dawg
- Joined
- Jan 21, 2009
- Location
- Fort Worth, Texas
- TDI
- 2009 Sportwagen (boughtback); 2014 Passat TDI SEL (boughtback)
Why not read and post in the very lengthy sticky on this subject? This "issue" has been discussed to death already, and yes, you can adjust your MFI with VCDS.
carlrx7
Veteran Member
my MFI read 39.8 and i got 38.2, -4.1%, meh close enough..
-Carl
-Carl
Lightflyer1
Top Post Dawg
I only pay attention to the instantaneous display anyway. What do I care if the cars estimated value doesn't match exact calculated value. I get a little surprise when I text it in to fuelly and it responds with the tank mpg.
VeeDubTDI
Wanderluster, Traveler, TDIClub Enthusiast
- Joined
- Jul 2, 2000
- Location
- Springfield, VA
- TDI
- ‘18 Tesla Model 3D+, ‘14 Cadillac ELR, ‘13 Fiat 500e
That's still better than the EPA rating. I also agree on discussing this in one of the two fuel economy threads already going (DSG or Manual).
minghi
Well-known member
hi, my MFI resets every day. I think there's also a number '2' on the MFI and I never see '1'? which might be the lifetime mpg for the tank?
APT
Veteran Member
When displaying any information that has a '1' or '2', push the OK button on the steering wheel controls to cycle to the next number.
'1' numbers reset automatically every time the car is turned off for at least 2 hours. '2' numbers reset only when done by the driver by press and holding the arrow button on the right side controls of the steering wheel.
EPA highway estimate is 40mpg for the DSG. You exceeded that by 8%. Many people beat that. But there are plenty of reasons hwy you only got 43mpg. Traveling at 75+mph gets a little lower. Colder temps. Wind. Less than 10 mile drives at any speed.
'1' numbers reset automatically every time the car is turned off for at least 2 hours. '2' numbers reset only when done by the driver by press and holding the arrow button on the right side controls of the steering wheel.
EPA highway estimate is 40mpg for the DSG. You exceeded that by 8%. Many people beat that. But there are plenty of reasons hwy you only got 43mpg. Traveling at 75+mph gets a little lower. Colder temps. Wind. Less than 10 mile drives at any speed.
compu_85
Gadget Guy
MFA 1 resets after the car is off for 2 hours. Tap the OK button to switch between 1 and 2.
-J
PaulB
Veteran Member
Well, I don't know. Over a single tank, with variations in the level of fill? And the tires don't have an exactly perfect diameter, but may be a little larger or smaller? And even the highway signs indicating each mile may be off some?
If the car is new, give it some slack. Takes a while to break it in...
minghi
Well-known member
thank you both (compu_85 & APT). i'll try it today
rjp0627
Active member
Don't get me wrong; I am getting better than EPA estimates and over all I am satisfied with the car. However that is a significant difference. It was 2 fill ups.
Lightflyer1
Top Post Dawg
Once you track the mileage for a while and find the percentage difference between calculated and display, you can adjust for this if you like.
ruking
Top Post Dawg
- Joined
- Mar 27, 2003
- Location
- San Jose area, CA
- TDI
- 2003 VW Jetta, 5 M, Reflex Silver: 09 Jetta, 6 Sp DSG, Candy White: 12 VW Touareg, 8 Sp A/T, Flint Gray
I would say don't be. I think the variables causing the differences are in the details you are not mentioning. Between the pen and ink and computer, I would tend to trust the pen and ink.
rjp0627
Active member
I don't understand. You fill up, reset the MIL, drive untill you need to fill up again, divide the gals. used into mileage. This was a round trip all highway driving. I'm just saying by doing the calculation on paper is more accurate. What Details??
My two cents..... 7 months; about 6300 miles; mixed driving; repetitive routes; driving style very ordinary, neither hyper-miler nor aggressive.
I get mid-thirties tank-to-tank; mid-high forties on the interstate at 75. Tank-to-tank about the same as previous '09 Jetta TDI over three years. Interstate mpg quite a bit better than Jetta which got 40-42. Both cars better than EPA sticker.
I get mid-thirties tank-to-tank; mid-high forties on the interstate at 75. Tank-to-tank about the same as previous '09 Jetta TDI over three years. Interstate mpg quite a bit better than Jetta which got 40-42. Both cars better than EPA sticker.
tdiatlast
Top Post Dawg
- Joined
- Jan 21, 2009
- Location
- Fort Worth, Texas
- TDI
- 2009 Sportwagen (boughtback); 2014 Passat TDI SEL (boughtback)
OP: You will find your answers in the "Real World" MPG stickies. There is an ongoing discussion there, and you will read everything you need to know about MPGs.
Ace Deprave
Veteran Member
- Joined
- May 29, 2012
- Location
- Louisiana
- TDI
- Former owner of a 2012 Passat SE TDI (traded for a 2015 Golf R)
FWIW, I have found that my MFD is more accurate since I have been taking my time and topping off the tank...basically letting the foam die down several times, and filling until there is non-foamy diesel in the neck. It's generally less than 1 mpg optimistic.
YMMV
YMMV
APT
Veteran Member
Even with pen and paper, any single fill up can be off by a fair amount, over 5%. The diesel foam often causes the pump to shut off. Yet, most people can still add another 1.5 gallons after that before it spills out. There was even a thread here about filling with nose of the car higher and lower making a difference in how "full" the tank gets.
I highly recommend using Fuelly to log and track your fills. Some people even add an MFI reading to compare vs. miles driven/gallons filled.
My MFI has pretty much settled at 1-2mpg higher than actual.
I highly recommend using Fuelly to log and track your fills. Some people even add an MFI reading to compare vs. miles driven/gallons filled.
My MFI has pretty much settled at 1-2mpg higher than actual.
Lightflyer1
Top Post Dawg
This is why it is so commonly preached to fill it to the brim each time you fill. Consistent fills to the same point will provide consistently good data when you calculate mpg. If you don't care the first "click off" of the pump will do fine.
ChadS99SVT
Veteran Member
Yeah I just use the MFI as an indicator of how I'm doing. (and it's fun to point out and gloat to people riding in the car lol).
I use Fuelly and for me it should be pretty consistant I usually fill up at the same exact station every time. fill up to the first click and that's it.
Winter has definately been noticeably worse. my snow tires probably don't help a lot either.
summer is around the corner and hopefully I will pick my MPG's back up then. either way I still am extremely happy with my mileage.
I use Fuelly and for me it should be pretty consistant I usually fill up at the same exact station every time. fill up to the first click and that's it.
Winter has definately been noticeably worse. my snow tires probably don't help a lot either.
summer is around the corner and hopefully I will pick my MPG's back up then. either way I still am extremely happy with my mileage.
Salsaman06
Veteran Member
Exactly. A key point is being consistent in how you fill up.
MyAvocation
Top Post Dawg
...except that fill rates vary between stations, so the only way to know for sure is filling to the neck, which requires some patience for foam to abate. Also, if you often fill from different stations and/or pumps, don't expect measurements to be exact.
If you plan to dial-in the MFD with VCDS, as Lightflyer stated, wait until after logging 6 or more fill-ups and average all of them to determine an accurate delta. Since VCDS only adjusts in whole percentage points, you'll never get it exact, but it will be very close.
And finally, for those of us in northern climates, MFD accuracy will drift between winter and summer temps.
If you plan to dial-in the MFD with VCDS, as Lightflyer stated, wait until after logging 6 or more fill-ups and average all of them to determine an accurate delta. Since VCDS only adjusts in whole percentage points, you'll never get it exact, but it will be very close.
And finally, for those of us in northern climates, MFD accuracy will drift between winter and summer temps.
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Salsaman06
Veteran Member
Canuck64
Well-known member
I did not know there was a page 2!
I just checked mine and after 13,500km or 8400 miles, my average fuel consumption according to the MFI is 5.6 l/100km or 40.7 mpg.
My average fuel consumption according to My Fuelly is 5.8 L/100km or 42 mpg.
A difference of 1.3 mpg calculated over 8400 miles makes one or the other, or both pretty darn accurate in my opinion
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Thunderstruck
Veteran Member
It can be adjusted with a VCDS. The MFI may lie a bit, but pen and paper won't.
I'm going to try to not be too fixated on mpg, 40-45 sure beats 19. I'm in Phoenix and folks are saying the mpg goes up with warmer weather. What can i expect when it's 108 degrees? I thought cold intake is best. Is it the opposite for TDI?