Mileage drops from 41 to 35mpg after 'fix'

TDI6Driver

New member
Joined
Jan 10, 2018
Location
MA
TDI
Jetta Sportwagon 6-speed
Hi, Newbie here, look like lots of great advice and I'm sure this has been discussed, but I've measured my mileage meticulously with every tank since I bought myTDI sportwagen (2014). Always hovered around 40mpg. After opting for the emissions fix I am now only getting 34-35mpg. Not happy about it. No drop in performance otherwise that I notice. Just wondering what recourse I have now???

Cheers,
 

kjclow

Top Post Dawg
Joined
Apr 26, 2003
Location
Charlotte, NC
TDI
2010 JSW TDI silver and black. 2017 Ram Ecodiesel dark red with brown and beige interior.
Drive more, pay more? That's the largest drop that I've seen reported. Typically, the fix seems to drop about 1 mpg. It might be that the computer adjustments have to learn to talk to all the components again and your mileage will come back up over the next few tanks.
 

SkeeterMark

Veteran Member
Joined
Jan 8, 2013
Location
North Branch, MN
TDI
2013 Jetta TDI 6M
You live in MA. It's been a really cold winter. Your car does not always get around 40 mpg because it is fact that they do worse in cold temperatures. Your winter mileage is ALWAYS going to average less than your summer mileage.
When you have a years worth of data, and can compare it to a years worth of data preceeding the fix, let us know.

I have every tank ever charted for 145,000 miles and can show you the swing between summer and winter, if you like.
 

tadawson

Veteran Member
Joined
Jun 14, 2013
Location
Lewisville, TX
TDI
2013 Passat TDI SEL, 2015 Passat TDI SEL
That, and a possible similarly timed change to winter diesel fuel, which also lowers mileage . . .
 

JB05

Top Post Dawg
Joined
Oct 20, 2005
Location
Il.USA
TDI
Golf,2005,anthracite blue
~36 with my last fill-up following three weeks of extremely cold weather in the Chicago area. I'm lucky to get 38 this time of year, but I also have a flakey CPS which may be a contributing factor.
 

BobnOH

not-a-mechanic
Joined
May 29, 2004
Location
central Ohio
TDI
New Beetle 2003 manual
Strike up a conversation with a chip tuner. Rocketchip and Malone are 2 many folks use.
 

IndigoBlueWagon

TDIClub Enthusiast, Principal IDParts, Vendor , w/
Joined
Aug 16, 2004
Location
South of Boston
TDI
'97 Passat, '99.5 Golf, '02 Jetta Wagon, '15 GSW
Hi, Newbie here, look like lots of great advice and I'm sure this has been discussed, but I've measured my mileage meticulously with every tank since I bought myTDI sportwagen (2014). Always hovered around 40mpg. After opting for the emissions fix I am now only getting 34-35mpg. Not happy about it. No drop in performance otherwise that I notice. Just wondering what recourse I have now???
How far have you driven? I wouldn't jump to any conclusions about FE until you've been through 4 or 5 full tanks. Monitors have to reset, which affects FE. And the weather here has been brutally cold in the last couple weeks. My MKVII has seen about a 10% FE drop from weather alone.
 

narongc73

Veteran Member
Joined
Nov 14, 2005
Location
VA/OH
TDI
2006 Jetta TDI
It's not the weather. It's short distance driving. My mileage is the same winter or summer. It's worse now that my commute is only 4 miles one way. Unfixed your car.
 

kjclow

Top Post Dawg
Joined
Apr 26, 2003
Location
Charlotte, NC
TDI
2010 JSW TDI silver and black. 2017 Ram Ecodiesel dark red with brown and beige interior.
My run to and from Indiana over the Holidays returned about 15% lower mileage than the same trip in July. Plus the July trip had bikes attached to the rear, so more drag. Frigid temps plus winter fuel caused this drop. I haven't gotten the fix yet.
 

TDI6Driver

New member
Joined
Jan 10, 2018
Location
MA
TDI
Jetta Sportwagon 6-speed
It may indeed be that my mileage is creeping up over the last few tanks...I will follow up with more data.
 

Mongler98

Top Post Dawg
Joined
Mar 23, 2011
Location
COLORADO (SE of Denver)
TDI
98 Jetta TDI AHU 1.9L (944 TDI swap in progress) I moved so now i got nothing but an AHU in a garage on a pallet.
YEP and your going to have to deal with it as TDI's are all fake emissions, remember the scandle? Deal with it, or sell it and go get a mk3,or 4.

the new TDI's are just choked to death with emmissions bullcrap and no longer can get decent milage. 35 is a bit low but it seems 38 is the new norm.

My mk3 was 43 when i got it at 180K miles. when i replaced the nozzes it was 45-46 and now easily gets into the 60's when on the highway.
 

tadawson

Veteran Member
Joined
Jun 14, 2013
Location
Lewisville, TX
TDI
2013 Passat TDI SEL, 2015 Passat TDI SEL
Consider also that you are now on winter fuel, and were not in June/July. That causes a drop all by itself . . .
 

IndigoBlueWagon

TDIClub Enthusiast, Principal IDParts, Vendor , w/
Joined
Aug 16, 2004
Location
South of Boston
TDI
'97 Passat, '99.5 Golf, '02 Jetta Wagon, '15 GSW
Currently I'm seeing 42/3 in my '15 GSW. My '02 Jetta Wagon is getting 46 in similar driving this winter. Since the GSW only has 7K on it, I think it's doing pretty well despite being "choked to death."
 
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