tips for fuel economy

oilhammer

Certified Volkswagen Nut & Vendor
Joined
Dec 11, 2001
Location
outside St Louis (where it's safe)
TDI
There are just too many to list....

Too expensive.

And we have at least one model sold here that was available in "regular", a diesel, and a [gasoline] hybrid: the NCS Jetta sedan.

Base price: $15k

TDI option: $22k

Hybrid option: $23k

So, theoretically, the "TDI+hybrid" would be around $30k... to start. Most would get tarted up, so would you pay for a $35k Jetta while the base model was sitting right next to it that started at $15k? I certainly wouldn't.

There was a diesel hybrid E-class sedan on display at the NAIAS a few years back. It was a Euro model, not ever sold here, although we did get the 4 cyl diesel like it had for three years. No idea what it cost, but it likely was not cheap.
 

NewTdi

Top Post Dawg
Joined
Jan 15, 2004
Location
NorCal
TDI
2003 Bora, Reflex Silver
Just an update on my quest for achieving better FE. In the past I used to get very good economy before I started with all the mods; however even with the mods these cars have way better FE than 99% of other combustion cars on the road.

I have been testing the P&G method as described on the early pages of this thread. When on the freeway and I do a lot of freeway driving I use the following technique. I gently accelerate for 5 seconds and I glide for 7-10 seconds. I can achieve on a my local highways an average range between 55-60mpg however in the 3 miles that it takes me to go from the freeway exit to the front door of the office my mileage drops to 51mog. These values are measured by a ScanGauge which has a margin of error if 0.0xx gallons. When I fill up for example my ScaGauge will tell me that the fuel consumption for the tank was 12.5 gallons however when I do fill up the actual fuel pumped might be 12.55; I wish there was a way to add one more decimal value to the ScanGauge. I run the tires at 38psi.
My car is somewhat modded with a BG "S7" turbo, PP502 nozzles and RC3+ tune.
I just wanted to share my experience here. In the past (5+ years ago) I used to participate in the monthly mileage competition and 700 mile tanks were often achieved.
 

Lightflyer1

Top Post Dawg
Joined
Sep 13, 2005
Location
Round Rock, Texas
TDI
2015 Beetle tdi dsg
Driving isn't supposed to be such a chore. I am happy with the mileage I get just regular driving down the road. No way I am going to do that constantly every 15 seconds over and over again. You must want that extra economy pretty bad.
 

NewTdi

Top Post Dawg
Joined
Jan 15, 2004
Location
NorCal
TDI
2003 Bora, Reflex Silver
Driving isn't supposed to be such a chore. I am happy with the mileage I get just regular driving down the road. No way I am going to do that constantly every 15 seconds over and over again. You must want that extra economy pretty bad.
After a while it becomes second nature and to some degree I agree with you, get in the car and drive/go. Bit I am glad to get those extra 3-5mpg without much effot.
 

Cbus27

Member
Joined
Feb 25, 2020
Location
PA
TDI
2002 Jetta ALH 2013 Jetta CJAA
Upgrades for fuel economy?

Hello,

This is the first time posting anything so forgive me if it’s not correct area or not enough info. I have a 2002 Jetta ALH w/ 5 spd manual and it’s stock. It has 297k miles and the turbo is about ready to go. I’m getting High boost PSI faults so I assume the VGT is sticking on turbo. I also assume it’s leaking a little oil which is common for the mileage and age.

I will be driving 115 miles all highway one way starting this summer 5 days a week. I am currently getting 43 mpg.

I contacted KermaTDI about a new turbo they suggested VN-17, new injectors 520 and a tune. I was quoted $2k for everything I need. I told them I wasn’t looking for a lot of power over stock but an increase in mpg or at least stay with what I’m getting now.

My question has anyone do this upgrade ? What mpg gain if any did you see ? Is it worth putting $2k into a 300k car. Mechanical it’s a great car and the body is good. Interior is excellent. I will just be using it to commute. I only paid $300 for the car and have put 15k miles on it already.

Thanks in advance.
 
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Lightflyer1

Top Post Dawg
Joined
Sep 13, 2005
Location
Round Rock, Texas
TDI
2015 Beetle tdi dsg
I would find the trusted mechanics list here and find someone close to you and have the car evaluated first. IDparts has a reman stock turbo for $529 if needed.

https://www.idparts.com/vnt-15-turbocharger-038253019c-reman-p-4608.html

I would skip the tune and injectors and just do a dieselpurge instead.

http://forums.tdiclub.com/showthread.php?t=87948&highlight=diesel+purge

You will never recoup the money spent for the tune and injectors from fuel savings. So don't do that unless you really need new injectors and want a tune. Stick with what is needed to run. If you can do your own work you should be able to keep it under $1k easily.

I would just keep it stock and get it in the best shape you can. You may not even need a turbo just yet. You have a number of trusted mechanics around you there.

https://www.google.com/maps/d/viewe...f96k&ll=40.316470609350816,-74.10828396875002
 
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Cbus27

Member
Joined
Feb 25, 2020
Location
PA
TDI
2002 Jetta ALH 2013 Jetta CJAA
I did a Moly diesel Purge back when I purchased the car. I have a lift and my good friend and I own 6 VW’s between the 2 of us. The labor will cost me nothing and I understand I will never recoup the actual $2k investment. Just wanted to know if anybody has replaced all these ? If there are any other better options out there ? I understand KermaTDI is a good company but as with any good salesman they push their products because the are in the business to make money.
 

Lightflyer1

Top Post Dawg
Joined
Sep 13, 2005
Location
Round Rock, Texas
TDI
2015 Beetle tdi dsg
That is probably about what you should expect to spend no matter who you got this stuff from. Tune, injectors and turbo. Just from my reading here and experience.
 

Cbus27

Member
Joined
Feb 25, 2020
Location
PA
TDI
2002 Jetta ALH 2013 Jetta CJAA
Well thank you all for the replys. I have some thinking to do. I plan on keeping car till I can’t fix it anymore
 

Cbus27

Member
Joined
Feb 25, 2020
Location
PA
TDI
2002 Jetta ALH 2013 Jetta CJAA
I have another question. If I up grade just the turbo to a VN-17 and the MAP sensor will I need a tune so it doesn’t over boost since it’s a larger turbo than what is on the car already
 

amit9

Veteran Member
Joined
Oct 7, 2004
Location
Toronto/Scarborough
TDI
2003 Silver Jetta TDI GLS 5MT
Check/Lube the lever on the VNT actuator arm, it helped restoring some power in my case.
Refer to: https://www.myturbodiesel.com/pages/tdi-wiki/
"VNT turbo actuator adjustment and repair/replacement on TDI engine-mk4"

Bigger turbo/Injectors/Tunes are all desirable upgrades, and as Lightflyer1 said, their costs will never be recouped.

Check/Clean the EGR valve and the intake manifold. At this age and mileage, those are probably clogged. Cleaning them is not much cost assuming you're DIY, and will give you some mpg increase.
Check/Adjust the rear brake parking cables, if the wheels are not rotating freely. The MK4 rear wheels are highly prone to sticking/dragging, and will lower the mpg.
Check all vacuum lines.

Hello,

This is the first time posting anything so forgive me if it’s not correct area or not enough info. I have a 2002 Jetta ALH w/ 5 spd manual and it’s stock. It has 297k miles and the turbo is about ready to go. I’m getting High boost PSI faults so I assume the VGT is sticking on turbo. I also assume it’s leaking a little oil which is common for the mileage and age.

I will be driving 115 miles all highway one way starting this summer 5 days a week. I am currently getting 43 mpg.

I contacted KermaTDI about a new turbo they suggested VN-17, new injectors 520 and a tune. I was quoted $2k for everything I need. I told them I wasn’t looking for a lot of power over stock but an increase in mpg or at least stay with what I’m getting now.

My question has anyone do this upgrade ? What mpg gain if any did you see ? Is it worth putting $2k into a 300k car. Mechanical it’s a great car and the body is good. Interior is excellent. I will just be using it to commute. I only paid $300 for the car and have put 15k miles on it already.

Thanks in advance.
 

jhonster

Active member
Joined
May 3, 2010
Location
Los Angeles, Ca.
TDI
2013 Jetta Sportwagen, , 2001 Jetta, 2000 Jetta
Hey there Oilhammer. I think you’re a VW tech. Right? If so, I had a question if you didn’t mind me asking.

I’m an auto tech as well. Mostly GM, Ford, Chrysler, Honda, Toyota stuff. Lots of drivability repairs. I’m a licensed smog tech as well. My 2013 VW Jetta Sportwagen TDI refuses you get better than 22-25 MPG. Dealership just replaced the hi press fuel pump, injectors, fuel filter etc about 8 mo ago. And replaced the EGR & DPF about 4 months ago. I complained both times about the fuel mileage & they say they can’t duplicate it. They reset the Av consumption & they say they’ve gotten 38 mpg the 1st time they did repairs & 42 mpg just this last repair. 8 mo ago the car did indeed get 38 mpg when they gave it back to me after the hi press fuel pump, but...it would lose about 1/2 to 1 mpg every day or every other day driving my usual daily 25 miles to work & 25 miles back home via the freeway. Until finally the MPG got back down to 22 mpg. It’s gotten 22-25 mpg since I bought the car used almost 2 years ago now. I keep telling the dealer they’re missing something. Either the O2 sensor in moving too slow, biased in voltage, or maybe the MAF is dirty or out of calibration. At either rate, this thing is reall starting to piss me off. I’m ready to trade it in for a car that has the urea system vs this one. My buddy w/a 2015 & a tune is getting 50+ mpg w/his Jetta TDI Sportwagen. Help Obiwan!!! Lol. ?
 

Rodmiser

Veteran Member
Joined
Apr 22, 2015
Location
N/A
TDI
Jetta s\DSG 2015 & 1&2 FIX
jhonster
You need a 60 min. trip about every three weeks, if not every two weeks.
Helps keeping it clean & clear, all the way 50 MPH at the low end. If not 70 MPH.
 

DeeJay

Member
Joined
Oct 3, 2020
Location
Michigan
TDI
2000 Jetta
Newer to the TDI crowd here (had a 1.6 back in the day). I've had a 2000 Jetta GLS 5 speed with 17 inch wheels for about 4 months now. It has 200k miles on it and seems to run right (except hard starts in the cold).I have a 100 mile daily commute to work and back. It's almost all expressway. I drive spirited and use cruise anywhere from 75-85mph everyday. I average about 42 each tank. I drove quite conservative for a tank and got 50mpg. If I drive like a normal person should, I get 45mpg. There is always some city driving on every tank. Oh, and I run 50 psi in the tires for lower rolling resistance. May get some different wheels and tires to get better mpg. On the coasting...I almost always hit neutral. I can coast a mile into town on my way home in neutral, but only about 200 yards with it in gear before I have to get back into the throttle. If I want to slow down, I will leave it in gear.
 

lennypizzas

New member
Joined
Feb 6, 2021
Location
canada
TDI
2014 golf comfortline sportwagen
i switched over to bridgestone turanza serenity plus tires after the factory originals wore out, and went from 5.2L per 100km to 4.7L per 100km without having to change my driving habits...they do however use more fuel in the colder winter months and are not recomended for winter driving
 
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