tips for fuel economy

Lightflyer1

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Joined
Sep 13, 2005
Location
Round Rock, Texas
TDI
2015 Beetle tdi dsg
On used cars I buy from people i do the same. For this car from the dealer though, I had them do everything as part of the sale. No sense not to.
 

CheapBastard

Veteran Member
Joined
Jun 12, 2019
Location
California
TDI
2014 JSW
What tire pressure do you guys run? Pumped mine up to 39, feels to roll more free than at 34 but it could just be placebo
 

Lightflyer1

Top Post Dawg
Joined
Sep 13, 2005
Location
Round Rock, Texas
TDI
2015 Beetle tdi dsg
Whatever is printed on the door card. You are doing things to save tiny slivers when just improving your driving will save you a slice. These are the kinds of things you do when your driving improvements won't/can't yield any better results.
 

akjdouglass

Veteran Member
Joined
Oct 3, 2013
Location
Mountain Grove, Missouri
TDI
2012 Jetta w/premium (sold to VW); 2014 Jetta Value Edition; 2015 Jetta SEL
Whatever is printed on the door card. You are doing things to save tiny slivers when just improving your driving will save you a slice. These are the kinds of things you do when your driving improvements won't/can't yield any better results.
Very true, if not very obvious to some. I do like to keep an eye on tire pressures, though, for reasons other than just fuel economy.

My biggest hit to economy is the obligatory errand-type driving close to home, which is even worse since the fix. My highway numbers are down some since the fix, but my city mpg seems to have taken a big post-fix hit. Before, a 60/40 city/hwy split reflected more of the highway average. Now, 20-30% city driving results in more of a "combined" tank average.

In any case, I'm still seeing numbers above the sticker EPA estimates for city, hwy and combined, so I can't really complain.
 
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Lightflyer1

Top Post Dawg
Joined
Sep 13, 2005
Location
Round Rock, Texas
TDI
2015 Beetle tdi dsg
It is 30/34/39 for my Beetle. Fuelly has me at 35 mpg average with no long highway trips and a 35 mile one way 3 days a week. I have never made a long trip only commuting, so don't know what the highway would actually be. Still beating the EPA estimate by 1 mpg for combined economy. My 2003 Beetle was about 44 mpg average for the same driving as was my 2005 Beetle. My 2012 Passat was around 42 but did way better on the highway. Somewhat disappointed in the current Beetle but it is still way better than a gas car and is fun and easy to drive. Not many of the 2015 Beetles were sold is my understanding and the Beetle is discontinued this year.
 

Mike14VW

Member
Joined
Jun 13, 2019
Location
Wilpo
TDI
2014
I think you have your thinking wrong! If something is plugged you have less flow !!!
Not sure what ur talking about. You can always give more throttle (fuel) to maintain the same speed of something less restricted.

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Lightflyer1

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Joined
Sep 13, 2005
Location
Round Rock, Texas
TDI
2015 Beetle tdi dsg
If the filter is clogged it will only flow so much fuel, no matter what throttle inputs you make. If it is so clogged that only an ounce of fuel can get through and you give it full throttle only an ounce will still get through because it is clogged. The more clogged it is the less that gets through, until none does.
 

Mike14VW

Member
Joined
Jun 13, 2019
Location
Wilpo
TDI
2014
Whatever you guys wanna think, changing the clogged/dirty fuel filter will maximize air/fuel ratio and as result, gas mileage will increase.

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Lightflyer1

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Joined
Sep 13, 2005
Location
Round Rock, Texas
TDI
2015 Beetle tdi dsg
Your statement was:

My 5houghts are the car sat and the filter may have taken on moisture with mold growing causing the filter pores to clog. Which in turn yielded the car to pull more fuel.
A clogged filter will not pull more fuel. That is the definition of clogged. Won't let anything through. If you are saying it passed more fuel when changed, well yeah a clean filter will do that.
 

Lightflyer1

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Joined
Sep 13, 2005
Location
Round Rock, Texas
TDI
2015 Beetle tdi dsg
Well your statement was unclear and led to the conclusion you were saying a clogged filter passed more fuel. I don't know how you can't see that in the statement quoted that you posted.
 

Mike14VW

Member
Joined
Jun 13, 2019
Location
Wilpo
TDI
2014
Well your statement was unclear and led to the conclusion you were saying a clogged filter passed more fuel. I don't know how you can't see that in the statement quoted that you posted.
Fair enough.

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jhonster

Active member
Joined
May 3, 2010
Location
Los Angeles, Ca.
TDI
2013 Jetta Sportwagen, , 2001 Jetta, 2000 Jetta
Whatever you guys wanna think, changing the clogged/dirty fuel filter will maximize air/fuel ratio and as result, gas mileage will increase.

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That’s just an incorrect statement. The maximizing of the A/F ratio is done by the oxygen sensor & the feedback controls. Stoichiometric fuel mixes come from the emissions system toggling rich/lean to achieve stoichiometricity & thus maximizing the air/fuel ratio. A plugged or restricted fuel filter will usually affect power, but you can still have a maximized air fuel ratio.
 

jhonster

Active member
Joined
May 3, 2010
Location
Los Angeles, Ca.
TDI
2013 Jetta Sportwagen, , 2001 Jetta, 2000 Jetta
LOL, you guys kill me. Seriously, if any 4 cyl TDI was getting 29 MPG you'd have a constant black cloud following you around. There simply isn't any way the engine could consume that much fuel. Or you have a fuel leak.
So. I’ve been meaning to post this for a while now.
Bought a 2013 Jetta sportwagen TDI in Feb of this year. Had a 2010 before this one that always got high 30’s (38mpg) on average. This one on the other hand has been getting 22-25mpg since I bought it. It had 93k when I bought it. Supposedly had the emissions update done (sticker under the hood). And the hi pressure pump just failed which was covered by VW about a month ago. So, with 98k on the car, and the timing belt 30k away, I had the dealer also replace the timing belt, tensioners, water pump, etc. I was hoping after all that work, that the mileage would pickup back to what my 2010 used to get. I drive mostly freeway & steady state 75-90mph. The car runs great & has plenty of power. Although the check eng light just came on & has stayed on. Code P2002 (8194 fac VW code) particulate trap bank 1 efficiency below threshold. The light 1st came on last Friday & it hasn't gone off. It's failed the testing parameter 4 times now. Any common failures that cause this issue where MPG is around 22?
 

Lightflyer1

Top Post Dawg
Joined
Sep 13, 2005
Location
Round Rock, Texas
TDI
2015 Beetle tdi dsg
I read another post saying clogged dpf's can cause this. Either not regenerating properly or clogged or something else broken causing this to occur.
 
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jhonster

Active member
Joined
May 3, 2010
Location
Los Angeles, Ca.
TDI
2013 Jetta Sportwagen, , 2001 Jetta, 2000 Jetta
I read another post saying clogged dpf's can cause this. Either not regenerating properly or clogged or something else broken causing this to occur.
But the mileage issue has been constant since I bought it in Feb. The check eng light issue with the DPF is just within the last week. I’ve been tracking the mileage since I bought the car 5 months ago.
 

jhonster

Active member
Joined
May 3, 2010
Location
Los Angeles, Ca.
TDI
2013 Jetta Sportwagen, , 2001 Jetta, 2000 Jetta
LOL, you guys kill me. Seriously, if any 4 cyl TDI was getting 29 MPG you'd have a constant black cloud following you around. There simply isn't any way the engine could consume that much fuel. Or you have a fuel leak.
Well. I’ve got a 2013 Jetta Sportwagen TDI that is currently getting 23 to the gallon. Yup. It’s been that way since I bought it in Feb of 2019. I’ve checked every tankful for months & thousands of miles. It’s crap.

I had the high pressure Fuel pump just crap out & the dealer replaced it at no charge. Had them do the TB, tensioner & water pump at the same time. The emissions update was done before I bought the car (sticker is there under the hood). The Ck eng light just recently popped on & the car has both a catalyst low efficiency code & an EGR code as well. I’m just going to take it back to the dealer & tell them to fix the check eng light & complain about the terrible mileage.
 

_Colty_

Member
Joined
Aug 5, 2019
Location
Minneapolis, MN
TDI
2011 Golf 2 door 6MT "DSLGATE"
Was getting 40-44mpg. Got a CEL for DPF efficiency blah blah. Warranty magic and 50-55mpg. Mine is a 2 door manual and I engine brake like a crazy person and draft a reasonable amount, but it made a big difference. VW will likely warranty it if you even have a "pending fault" which a cheap $12 amazon OBD2 to Bluetooth scanner (with Torque pro) will be able to tell you about.
 

Brandon_2156

Member
Joined
Jun 23, 2019
Location
Indiana
TDI
MK6 2.0 jetta
1st I keep trying to search but the search box disappears, anyway. Has anyone used the Malone tune and noticed a gain in fuel economy (I was looking at the stage 2 and dsg tune)
 

Lightflyer1

Top Post Dawg
Joined
Sep 13, 2005
Location
Round Rock, Texas
TDI
2015 Beetle tdi dsg
The tunes are for performance mostly not economy. Some do report economy gains though (when not using the power) but not enough to offset the cost of the tunes. $1k buys a lot of fuel! Not to mention loss of warranty if you have any left. The best thing for increased fuel economy is changing the way you drive. That in a nut shell makes the most difference than anything you can do, and it is free.
 

Brandon_2156

Member
Joined
Jun 23, 2019
Location
Indiana
TDI
MK6 2.0 jetta
I average 30mpg highway only, not taking off like I'm drag racing. The speed limit is 70mpg to work for 30miles so I'm at 70-57mph at 2200-2400rpms. Im just confused because my wife has a 2019 Toyota Corolla that averages 27 highway/city. Uggg lol
 

Lightflyer1

Top Post Dawg
Joined
Sep 13, 2005
Location
Round Rock, Texas
TDI
2015 Beetle tdi dsg
Not trying to be rude but either there is something that needs attention with your car or you need way better driving skills. I wouldn't exactly say a 30 mile drive at speeds varying between 55 to 70 mph lend themselves to really call your driving "all highway". Is your car an auto or manual? How you drive in that 30 miles is going to make a huge difference. You can't be speeding up and slowing down all the time. I would read up on eco driving and find someone with VCDS near you to scan the car and check things out for you. Even a dragging brake could account for your bad economy. It needs some investigation of your car and your driving to improve anything. Not something we have enough info to really help with at the moment. If you have a car issue or bad eco driving skills a tune won't help and may hurt even more. The first rule of tuning is to make sure your car is in tip top shape before doing anything.
 

Brandon_2156

Member
Joined
Jun 23, 2019
Location
Indiana
TDI
MK6 2.0 jetta
No I don't take it as rude, I should have previewed my post, the speed limit is 70. So I set the cruise at 75, it is automatic. The only other speed change is when I get into the office ramp for the last few miles it's 55mph the rest of the way to work. But your right I will have someone look at. Because I don't have the diagnostic tools. I have had 2 others agree that something has to be wrong or maybe the new software that VW used to pass emissions could hurt also. Thanks for the help
 

Lightflyer1

Top Post Dawg
Joined
Sep 13, 2005
Location
Round Rock, Texas
TDI
2015 Beetle tdi dsg
Read up on eco driving as well. Cruise control isn't exactly the best choice necessarily. Slow down. Do 65 in the right lane and let the other traffic go by you. In 30 miles it will only add minutes to your drive and the fuel economy will go up. Wind resistance above 60 mph makes a huge difference as speed increases beyond that. Dropping from 75 to 65 should show a decent increase in economy.
 

asgoodasdead

Well-known member
Joined
May 6, 2019
Location
NJ
TDI
2011 Jettta Sportwagen TDI
i do cruise control anywhere from 72-78 commuting to work and i still average around 40mpg.


i only fill up with shell, exxon diesel efficient, or bp/amoco and always keep my tires at 35psi.


manual trans
 

vincej

Veteran Member
Joined
Jun 26, 2015
Location
Calgary
TDI
2014 Golf Wagon
When we can get these things in diesel electric it would be nice to see the fuel economy at least double what we are getting now.
 

Drys

Member
Joined
Oct 17, 2019
Location
Mid-A
TDI
'15 GSW SEL
When we can get these things in diesel electric it would be nice to see the fuel economy at least double what we are getting now.
I don't think a diesel-hybrid will ever make it to the states, at least.
 
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