mpg low???

mud slut 350

Member
Joined
Sep 28, 2012
Location
navarre fl
TDI
2012 jetta tdi dsg
Okay I just bought a v2012 VW Jetta TDI DSG for my wife and I. We love the car its a great car so far in the few weeks we have owned it. There is just a few problems im having and a few questions. 1. we have filled it up twice since owning it and the first time mpg was about 36 and second 35. now it is good but still not as great as others im hearing about and as everyone would tell me it would get at least around 40. this driving is a pretty even mix of highway and city. these are numbers i get when i fuel up but the numbers on the dash say 38 or 39 avg mpg. which is more accurate???:rolleyes: it really upsets me when im expecting 40+ but im only getting 3 more mpg than our previous dodge neon sxt, that was paid off and only $5k :mad: . can anyone enlighten me on maybe something they did to the car or if it got better over time? the dealer said it only takes 500 miles to break in the engine but i know as a mechanic myself that it takes at least 3000. 2. how is the mpgs measured on the car is it by fuel flow and mileage or speed and mileage or rpm or what.
3. and my last question. is there any plug and play chips on the market right now for more power? and can the DSG trans handle much more? and is there any better exhausts? turbo back? i want to eliminate as much emissions stuff as i can off of the car as i know they severely hinder economy and performance and decrease longevity of an engine.
 

Cogen Man

Veteran Member
Joined
Jun 4, 2011
Location
Kingston, Ontario, Canada
TDI
2011 Golf TDI DSG.
It takes more than 500 miles to fully break-in a diesel engine for optimal mpg. How many miles do you have now ? 35/36 mpg isn't that bad. It will get better in time.
 

vtbigdog

Veteran Member
Joined
Nov 2, 2011
Location
Vermont
TDI
2012 Jetta TDI DSG
I have the DSG and experienced the same MPG as yours...that is, until I hit about 1,500 miles when it started to increase. I have now averaged 44.85 MPG over 16K miles.

Are you running the air or driving with the windows down a lot? That will make a difference.
 

deoncollins69

Member
Joined
Mar 29, 2011
Location
Rantoul
TDI
2011 jetta sedan 6spM
Poor mpg

I had the same experience with my 09 tdi/dsg. Same drivetrain as yours! I never saw better than 37, ever! I finally traded it in on a new tdi/6spdm which ive been getting 47-51 out of. I'm assuming my first tdi was not properly broken in. I'd look up some break in tip right here and follow them to a t. Good luck! Hey even if you don't hit forty mpg at least you can drive it till the o.d. Says 300000!
 

under dog

Well-known member
Joined
Sep 26, 2012
Location
Longview, WA
TDI
2015 Audi A8L
I have about 300 miles on my 13 TDI/DSG and I'm seeing steady 40mpg. I think a lot of it depends on how you drive it. But I have always heard that TDI's getting better and better MPG the older they get.
 

mud slut 350

Member
Joined
Sep 28, 2012
Location
navarre fl
TDI
2012 jetta tdi dsg
i know it is def not going to take tens of thousands but not 500 for damn sure! where are these berk in procedures u talk about? my wife drives with ac on ive been leaving it off and windows pretty much up all the time. i know all that makes a difference. the second tank i babied it even more and that was the one i got the 35 on. still no one answered the accuracy of the mpg on the car its about 4-5 mpg higher than what im calculating. i really dont believe it is accurate at all. is there any emissions stuff you can readily pull off to help??? i know everyone's green this green that but to tell you the truth killing mpgs i think hurts everything the most im trying to find a diagram or pdf or something on the engine and trans that will show all the emissions stuff on the car.
 

irondogger

Well-known member
Joined
Aug 24, 2012
Location
South Texas
TDI
'12 Sportwagen TDI
MPG Increase

I have heard anywhere from 2000 to 5000 before you start to see the MPG creeping up. My experience is about 5000 having owned 3 diesels, a Cummins and 2 TDIs.

I never trust the in vehicle display for MPG. Hand calculated is the only way to go. I believe the electronic display is fuel flow and mileage to calculate MPG. I know on my Ram P/U when I put a add-on 'box' my displayed MPG increased significantly but in reality it decreased slightly. The boxes 'fool' the ECM to get more fuel to the injectors.

I hope the MPG numbers increase for you in the near future.

L8r,.............irondogger
 

lildevildee

Veteran Member
Joined
Oct 8, 2003
Location
Knotts Island, NC
TDI
2012 Jetta w/6spd manual
mud slut, IIRC, it takes approx. 60,000 miles for these engines to reach optimum compression.

My m/t is about 39mpg for the life; however, the last 2 tanks have been a bit better than that. On my old tdi's, I hit break-in spots around 5000, 7500, and 12,000 ~ 15,000 miles. On my new tdi, my first break-in seemed to be closer to 7100 miles.

BTW, I'm from Navarre :)
 

TDI_Timmy

Veteran Member
Joined
Feb 13, 2011
Location
Seattle
TDI
2012 JSW, DSG, Pano
My computer always reads a bit high.

Couple questions - how fast are you driving on the highway? Higher speeds coupled with the DSG kills mileage.

I know that tire pressures don't affect a lot with mpg, but they can influence it - what PSI are your tires at? I set mine to 38.

I do mostly city driving and my overall mpgs are slightly less then yours.
 

sclevine

Well-known member
Joined
Sep 3, 2011
Location
Bronx, NY
TDI
2011 Jetta TDI DSG
If your driving is 'an even mix between highway and city' then I don't think you're going to see the super high MPG others get.

I live in NYC and when I drive around NYC, my MPG can be quite low. Most of my driving is 50 mile highway drives out and back in New Jersey, and my overall average is about 39 MPG. The less driving I do in the city, the higher my MPG. In summertime my MPG is also much lower due to running the AC, and increased traffic congestion.

Yes, in my opinion, the MPG you see on the dash is a bit high. Today it told me I was at 40.6 for the tank, but when I filled up, I only got 38.5.
 

mud slut 350

Member
Joined
Sep 28, 2012
Location
navarre fl
TDI
2012 jetta tdi dsg
not sure on tire pres ill check it after this post. my wife drives on the highway im guessing around 75. I know i may be asking to much but like i said ive heard people saying around 40 avg of mixed driving. oh well. my wife is from navarre im stationed at herby devildee. no one is able to pull up like an ipb or pdf of the emissions stuff on this car? maybe a link that does?
 

mud slut 350

Member
Joined
Sep 28, 2012
Location
navarre fl
TDI
2012 jetta tdi dsg
i still dont think it takes that long. a lot of people think diesels take longer to break in but i dont believe they do. i dont see where it talks about break in on your link
 

lildevildee

Veteran Member
Joined
Oct 8, 2003
Location
Knotts Island, NC
TDI
2012 Jetta w/6spd manual
Sadly, not once have I seen mud slut say they actually love driving the car. Methinks they would have been better off to stay in the neon they had...

Quick, mud slut, when are you doing the first oil change in your car?
 

I800C0LLECT

Veteran Member
Joined
Sep 27, 2012
Location
Williamsburg, VA
TDI
2012 Jetta & Passat
I know I'm new to this...I had a big issue with my Pontiac Grand Prix GTP when I moved from a 3000 foot elevation to sea level. I was getting 33mpg highway and about 24mpg city. Once I made the move to sea level my city dropped massively to between 17 and 19mpg. My highway was only about 25mpg.

I will say that another change in circumstance was that I went from a 91 octane 100% gas to 93 octane and 10% ethanol mix.

However, after purchasing the TDI and reading up on people's 40+mpg experience I've paid attention to geography because I haven't achieved what others claim either and it's hard to believe that I have major problems across two entirely different platforms. My fuelly isn't that impressive but I'm only doing a 5 mile commute to work currently. When I am on the interstate I've been able to achieve ~40 to 42mpg at 75mph up from about 38 to 39 when I first purchased the car. My city mpg is right at to just above EPA rating. Getting back to geography, I haven't noticed others at sea level getting anything that's drastically different. A nice tail wind netted about 52mpg on a 100+ mile trip and that's about the best I've achieved which is far and away from my usual statistic. Granted, it was a single trip and it was before I used fuelly so I don't have record of that.

In the end, I have a feeling that your location plays a big role in your mpg performance. Don't get down on it. I thought my grand prix must have had something terrible happen. Then I started wondering if my jetta was a lemon. As much as I want to be part of the hype and 800+mpg crowd I decided to be patient and now I'm definitely seeing a bigger improvement since I have more miles on the car.

Hope this helps too :/

http://forums.tdiclub.com/showthread.php?t=252501

http://www.fuelly.com/driver/i800c0llect/jetta


EDIT: Fixed link
 
Last edited:

pinkertonfloyd

Veteran Member
Joined
Jan 2, 2012
Location
Roseville, CA
TDI
14' Subie Outback FMR: 12' Jetta TDI/P+N
For the record mine was about 30-32 mpg at first I'm now at 8k and its now 38... I drive mostly city to boot. I took a few trips and have hit 50+ mpg. basically the mpg will start going up after 5k. don't change the oil until 10k and diesels like to be driven hard to seat when new... look at the break in posted on here and follow as closely you can.
 

mud slut 350

Member
Joined
Sep 28, 2012
Location
navarre fl
TDI
2012 jetta tdi dsg
haha spark plugs along with blinker fluid to right pdt? and winter tire air? I do love the car the only thing is i guess i was expecting at least 40 overall since my wife drives to pcola nad back almost every day which is mostly interstate. the car overall is great i mean its a nice ride and they dont look to shabby either.
 

pdt165

Veteran Member
Joined
Jul 28, 2011
Location
Fl
TDI
2011 Jetta 6 speed (Bought Back)
Not sure if this was mentioned, but what mode are you driving it in? The Sport mode will burn through diesel alot faster than drive.
 

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.
With about 40K miles on my JSW, I am settling into low 40s on the interstate between 70 and 75. 43 for my last trip. Around town, it stays around 36. My commute is only 5 miles. My daughter is driving it for now while we try to sell her 05 Corolla. Her commute for 4 out of 5 days is about 3 miles. She is also having issues adjusting to the dsg, so am sure there are a lot more jack rabbit starts. I find the computer to be close to hand calculations but never exact.

Hang in there. Mileage will go up and your driving skills will adapt to the dsg to give better mileage in town. Try running with the instant mileage mode turned on and see where your big drains are.
 

TDSA

Active member
Joined
Jun 4, 2012
Location
Texas
TDI
2012 Jetta TDI DSG w/Premium
I too have been quite disappointed in the fuel economy. I have 5,000 miles on my DSG. I have it almost exclusively in D and drive about 60% highway / 40% city roads.
The computer tells me I'm getting between 39-47 MPG.

In reality, I'm getting about 35 MPG.
 

vtbigdog

Veteran Member
Joined
Nov 2, 2011
Location
Vermont
TDI
2012 Jetta TDI DSG
The number one way to improve mileage....slow down. You will be happier and the extra two minutes it takes to get somewhere is generally a small price to pay.
 

WutGas?

Veteran Member
Joined
Feb 28, 2012
Location
Oklahoma City
TDI
The Last Real Jetta Sedan
In my opinion, you just have to learn to drive it for efficiency. That doesn't mean hypermiling, or going too slow. There is a learning curve to the DSG and a diesel engine in my opinion. I know the more and more I drive mine, the easier it is to get better MPG. I don't think anything is happening with the engine, it's just me figuring out what works and what doesn't.
 

TDI-Photog

Veteran Member
Joined
Aug 21, 2011
Location
Minneapolis
TDI
2011 Jetta TDI 6m
not sure on tire pres ill check it after this post. my wife drives on the highway im guessing around 75. I know i may be asking to much but like i said ive heard people saying around 40 avg of mixed driving. oh well. my wife is from navarre im stationed at herby devildee. no one is able to pull up like an ipb or pdf of the emissions stuff on this car? maybe a link that does?
I get about 40 mixed. But it varies based on factors like tire pressure, temperature (cool being best vs. hotter or colder), how hilly it is where I'm driving and wind.

I did 2 similar--mostly highway--trips, one with strong winds blowing and one with none. Windy MPG was about 41MPG; Calm MPG was 49. (Both MPGs were round-trip.)
 
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