Newbies and Vets: Tips for better fuel economy!

katzw

Well-known member
Joined
Jun 28, 2007
Location
Vancouver
TDI
2005 Jetta TDI Wagon
wri: thanks for addressing it - i don't shut off my car at lights when it's cold, but some of the long ones here in vancouver (kingsway and boundary anyone?! GAH!!! 7-10 minutes in rush hour of letting the car coast in stop .. stop.. stop.. traffic) are worth the shut-off. I was just a bit worried about wear and tear on the starter.
 

Uncle Milty

Veteran Member
Joined
Feb 9, 2008
Location
Prince Edward Island, Canada eh.
TDI
2001 VOLKSWAGEN JETTA GLS TDI
So... my 38.68 miles per US gal with a '01 that is showing 200000 plus miles, on a -4 F day, with four adults on board, during a run that included some city driving, is normal then?
I was hopeing to see the north side of 40, but hey, I'm in Canada, eh, so I got 46.5 mpg with our big gallons;)
 

BleachedBora

Vendor , w/Business number
Joined
Oct 16, 2003
Location
Gresham, Oregon
TDI
'81 DMC-12, '12 Audi TT 418 hp/383 tq, '08 GL320 CDI 275 hp/448 wtq - '81 Caddy ALH, '04 Golf BEW 2" Lift, '85 HMMWV
I don't know if I'd call that normal, again it depends on fuel quality (sorry, I have no info at all for C-eh-n-eh-d-eh, so I'll let our brotha's in 'da North report when they find high cetane information.... :)
I've been driving in 5-15 degrees lately and just had a 50 MPG tank, mostly highway. Before that I had a lot of mostly city and netted a 44 last tank...That's all on B20.
-BB
 

BleachedBora

Vendor , w/Business number
Joined
Oct 16, 2003
Location
Gresham, Oregon
TDI
'81 DMC-12, '12 Audi TT 418 hp/383 tq, '08 GL320 CDI 275 hp/448 wtq - '81 Caddy ALH, '04 Golf BEW 2" Lift, '85 HMMWV
Utah has been 10 degrees off and on, although it's warming up now. I was just in Rexburg, ID where the low was -22 and the high was 5 or so...When I was in Nebraska and SD last month it was -5; I still got around 42 MPG.
 

Uncle Milty

Veteran Member
Joined
Feb 9, 2008
Location
Prince Edward Island, Canada eh.
TDI
2001 VOLKSWAGEN JETTA GLS TDI
When ya'll are reporting those nice fat (or is it phat?) fuel mileage numbers are you driving alone or with weight of passengers and/or other junk?

I do wonder about the 344444.xx kms effecting the efficiency of the engine.
 

fs0449

Member
Joined
Jan 18, 2008
Location
Michigan
TDI
none yet, waiting for 2008 model
darkscout said:
Dude, don't loose your mind. I was just making a joke up they're. If you come off you're rocker that quickly I wonder what you have up their in your noggin. Sounds like a screw lose or something. I mean I didn't try to effect you in anyway, but now look how you've gone and disrupted the affect the original poster had. Here me out, there are a lot of people that are knew hear. You should calm down than come back.
Man, your spelling leaves something to be desired. But otherwise I agree with you.
 

rustytigwire

Member
Joined
Nov 3, 2007
Location
Norman, OK
TDI
03 Golf egr delete
Bought 03 golf 41mpg drive home 500 mi. next tank 39 drove really hard. next put in 10 gal / week and 5th tank top off. avg was 41.53 mpg. for 1500+ miles. it had been hard to start and local Dan W did vag com... inj timing was off the scale retarded. he is a hero for helping me correct that. am trying desparately to run more fuel thru to see how much improvement I got. BUT IT WON'T USE IT FAST ENOUGH.

BB i miss parleys on the BMW R100s.
 

deezulmark

Veteran Member
Joined
Jul 18, 2006
Location
Elizabethton, TN
TDI
96 Passat Wagon
Walmart/Murphy cetane?

Just ran across this thread. Thanks BB for the cetane #s reported by the various brands. Anybody know Walmart's supplier and cetane? They're always way cheaper than anybody else in town. Usually have been doing Flying J on trips as they're cheapest, but now I know to try BP and Shell and see.

Now if they would quit making diesel so much more expensive than gas! But then it is winter, so home heating oil demand pushes it up to some extent.
 

Jimwsea

Veteran Member
Joined
May 14, 2005
Location
Portland, Ore. area
TDI
99.5 Golf GL
Mike out west said:
Am I missing something here? Doesn't the best cetane per dollar come from blending 2-3% biodiesel with the cheapest fresh, non-dirty fuel around (e.g. Flying J, Arco)?
Mike out west - Adding 3% biodiesel would improve lubrication, but it would only raise the centane number by about half a point.
 

DannyRay

Well-known member
Joined
May 9, 2006
Location
Priceville, AL
TDI
2002 Jetta GLS TDI
Thanks for the advice on fuel quality. I have been running that truckstop stuff with statadyn (or whatever) additive. I will try the more expensive BP and Chevron and see what I get. My son says he gets way better gas mileage in his gas Volvo with the Chevron over the other stations which now are most putting 10% alc in. I am amazed by my modified car still gets ~39 mph and with wide tires and auto. I do coast some by going to nuetral if I know I will be slowing or staopping and then match rev's when dropping back into drive. I run my tires at 44 psi max.
 

Fencemaker

Veteran Member
Joined
May 12, 2006
Location
Washington, PA (SW PA)
TDI
2006 Jetta TDI 5sp; 2009 JSW TDI 6sp
Guys, this is about the best thread for we newbies trying to max fuel economy in our new-to-us tdis. But I've got a question that I'm hoping someone can quickly answer.

I know this is a very elementary question, and I don't want to restart the whole coasting in gear v. coasting in nuetral debate b/c that has been beaten to death. But, I'm new to tdi's and would like further explanation to help me with my fuel economy driving techniques.

BB says in Rule 4 of the OP: ". . . when you are coasting in gear you use no fuel until you reach ~1200 RPM."

Does this mean that when coasting in gear you use no fuel at RPMs below or above 1200 RPM?

The answer will greatly help me in my decisions as to when to coast in gear v. when to coast in nuetral. Thanks so much for your help.:)
 

BleachedBora

Vendor , w/Business number
Joined
Oct 16, 2003
Location
Gresham, Oregon
TDI
'81 DMC-12, '12 Audi TT 418 hp/383 tq, '08 GL320 CDI 275 hp/448 wtq - '81 Caddy ALH, '04 Golf BEW 2" Lift, '85 HMMWV

MightyCuinn

Active member
Joined
Apr 1, 2008
Location
Carrollton, Texas
TDI
1998 Jetta
So I've read through this, and admittedly, I'm a newbie.. but what is a 'ventectomy'? I'll be looking for any and every way to get the best MPG...
 

JettaJake

Veteran Member
Joined
Nov 26, 2002
Location
CT TDI Corral
TDI
'03 GLS 5spd
Ventectomy is the <5 minute mod to the valve you will see just inside the fuel cap (at the ~9 'o clock position in an '03). A basic search should turn up multiple threads.

The mod is to simply remove the guts of the valve and all this does is make filling to the brim easier since you do not have to "burp" the air from the tank and you can fill the whole neck of the tank w/ fuel (hopefully something besides the FlyingJ stuff :p ) with no delay.

Coasting in neutral is a plain and simple bonehead move IMNSHO.

The 0.681 is a def top 10 mod and it can be had for well under $300, esp. if as previously noted you can sell the old gear. Besides, straight payback is not easily calculated nor is it necessary. Just for starters, what's it worth to have less overall viibration? Not sure, but it a definite and significant (positive) number. The rpm drop is 11% and the mileage bump works out to ~5% for Jake.

diesel on -- ymwv
 

AudiLikeA4

Veteran Member
Joined
May 26, 2004
Location
Middle Tennessee
TDI
2004 VW Golf GL Anthracite Blue Manual
JettaJake said:
Coasting in neutral is a plain and simple bonehead move IMNSHO.
Is that really necessary? Name calling? I coast in neutral and get exceptional mileage doing so, and noone gets hurt...except big oil:)
 

JettaJake

Veteran Member
Joined
Nov 26, 2002
Location
CT TDI Corral
TDI
'03 GLS 5spd
"Bonehead move" is name calling? Okay, in a roundabout way I suppose but as a veteran memebr I am surprised your skin's that thin! Crybaby!! :D

Coasting in neutral? Is that really necessary? I almost never coast in neutral and get exceptional mileage. I sometimes wonder how much more exceptional would my numbers be if I coasted at every opportunity, but then I shift gears and forget about it.
 

Barbarosa

Member
Joined
Mar 26, 2008
Location
Arkansas
TDI
2003 Jetta
I'm afraid I have to step in here in defense of coasting in neutral. I find it very beneficent to my mileage, although in a couple of the places on my route I coast I do so for upwards of 2.5 miles and reach speeds of about 75 to 80 mph, so I may be somewhat biased in my reasoning.
 

BenRunner

Active member
Joined
Jul 23, 2007
Location
Bowling Green, KY
TDI
Past: 97 Passat TDI Now: 02 Jetta & 06 Jetta
Speaking of a Ventectomy...When I got my 97 Passat a few months ago it had the smaller hole in the neck of the filler...now it's gone and there is just a big fueling pipe there. Does that mean it gave itself a Ventectomy??
 

freebsd

Member
Joined
Aug 18, 2005
TDI
Jetta PD wagon, 2004, Silver
I have been reading this board for years, it is a great place. Here I share my experience with my 2004 Jetta GL PD Wagon(made in Germany), stick shift. For the past two years or so, I have been filling my tank with B5(ULSD), every time I fill about 14(+/- 0.2) gallons. My best tank was 750+ miles, my worst tank was 690+ miles(last winter), except which I have always maintained 700+ miles per tank. I checked my odometer against the highway marks(upto 300 miles), it is accurate in the 5th gear(even slightly under estimates), I don't know whether it is accurate in lower gears, never bothered to check. I typically drive 80 to 90% high way, at various speeds(as fast as the traffic allows). I guess one thing many owners could have neglected is the tire pressure, the manual says 45/36psi, I pump the rear tires to 45 as well(by the way, the local stealership is really stupid, they lowered my tire pressure to 30psi when I brought my car in for the first two free oil changes.)
 

Russell G.

Member
Joined
Apr 15, 2008
Location
Minnesota
TDI
2001 Jetta
242,000 and still going strong

Thanks for all the ideas about increasing the fuel mileage in the TDI. Mine seems to have slipped with advancing mileage. It was 50.7 in it's prime--using Premium diesel fuel, cruise control on, and 70-75 degrees, so no A/C required. Have used full synthetic oil since it was new --- Rotella 5W40. Had the intake cleaned once at 135,000 miles, checked at 225,000 it was still clean. I am brand new to this.....so please be patient. "God's not done with me yet." Thanks.:D
 

NarfBLAST

Top Post Dawg
Joined
Mar 3, 2002
Location
Waterdown, Ontario, Canada
TDI
2001 Golf 5MT
marspball said:
Are there any settings on Vag Com that you can change for optimum fuel efficiency?
I'm not sure, but I tried adjusting channel 1 "Fuel Quantity at Idle" from 2.2mg/stroke to 4.0mg/stroke (ideal according to the FAQ) and now I can see with the Scangauge I am burning about twice as much fuel at idle with no lights or accessories running. That is fine and to be expected, but the scary thing is that my fuel economy has gotten worse as per scangauge... this tank is running close to 7.0L/100km after driving 300km, when I used to do less that 6.0L/100km!! I've been running Scangauge for many tanks without changing 20% calibration, I know one of BleachedBora's things is to never trust the computer, but I do. Anyway, will check on paper with next fillup.

This adjustment is right in the TDICLUB.com main FAQ. I originally performed the adjustment to get rid of shudder when idling, and it definetly fixed that, but why should it affect economy when driving? Anyone else played with "Fuel Quantity at Idle"?
 
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NarfBLAST

Top Post Dawg
Joined
Mar 3, 2002
Location
Waterdown, Ontario, Canada
TDI
2001 Golf 5MT
CETANE at SUNOCO in Canada, eh?

Sunoco seems to be the only diesel provider in Canada that actually has two different grades of Diesel, so I sent them this email and got this reply.

Dear "Info Sunoco WEB Site Mail" <info@sunocomail.ca>,

I searched sunoco.ca but could not find CETANE numbers for regular or gold Diesel. Can you please provide these numbers? Thanks!

Thank you for your email. In answer to your questions:

Ultra low sulphur diesel has a minimum cetane rating of 40
Ultra low sulphur Gold Diesel has a minimum cetane rating of 45
For your reference, we have highlighted some key points regarding both the immediate and long term benefits of our Sunoco Gold Diesel for your convenience.
Immediate Benefits:
· Gold Diesel has "higher cetane rating", therefore our customers will get quicker starts (especially in cold weather) and smoother running engine with less smoke and emissions. Sunoco Gold Diesel is guaranteed to have a 45 min. cetane number and often exceeds that by 1-5 cetane numbers.
· Gold Diesel has a water de-hazer and a de-icer, which helps to prevent water freeze-ups, especially in really cold weather.
Long Term Benefits:
· Gold Diesel has a great detergent which will keep engine parts clean, especially fuel injectors!!! Clean injectors are necessary for maximum power and fuel economy.
· Gold Diesel has a lubricity improver to provide added lubrication to engine parts (versus the base diesel product), such as fuel pumps.
· Gold Diesel has corrosion inhibitors and stabilizers to keep decomposed fuel from fouling or attacking engine fuel system components ………this can reduce need for maintenance over the life of a diesel engine.
Please feel free to contact me directly at the following email address or at either number noted below should you require further information.
Best Regards,
Jenny Stathopoulos
Customer Relations Co-ordinator
416-733-7423 / 1-888-858-7242
 

NarfBLAST

Top Post Dawg
Joined
Mar 3, 2002
Location
Waterdown, Ontario, Canada
TDI
2001 Golf 5MT
I just emailed PetroCanada, Esso, and Truck Town Terminals, inquiring about their CETANE ratings because their websites didn't mention them either.

Shell.ca has a interesting (if out dated) write up entitled:

Diesel engines will run, more or less happily, on almost anything, including coal dust. Getting the most out of them - on a daily basis and over their lengthy lives - is another matter entirely.

here is the link,
http://www.shell.ca/home/Framework?...for_motorists/fuels/diesel/diesel_shared.html

And they actually mention that pre ULSD the minimum cetane in Canada was 40. Anyone have new info?
 

nicklockard

Torque Dorque
Joined
Aug 15, 2004
Location
Arizona
TDI
2010 Touareg Tdi w/factory Tow PCKG
NarfBLAST said:
I'm not sure, but I tried adjusting channel 1 "Fuel Quantity at Idle" from 2.2mg/stroke to 4.0mg/stroke (ideal according to the FAQ) and now I can see with the Scangauge I am burning about twice as much fuel at idle with no lights or accessories running. That is fine and to be expected, but the scary thing is that my fuel economy has gotten worse as per scangauge... this tank is running close to 7.0L/100km after driving 300km, when I used to do less that 6.0L/100km!! I've been running Scangauge for many tanks without changing 20% calibration, I know one of BleachedBora's things is to never trust the computer, but I do. Anyway, will check on paper with next fillup.

This adjustment is right in the TDICLUB.com main FAQ. I originally performed the adjustment to get rid of shudder when idling, and it definetly fixed that, but why should it affect economy when driving? Anyone else played with "Fuel Quantity at Idle"?
You need to zero out and recalibrate the scangauge. It makes its calculations based on IQ value and the learned adjustments from your tank fill input values.

It should be off wildly since you changed IQ. Don't sweat it. :) Just recalibrate. It may take 3-4 tanks to get back to within +/- 3% accuracy.
 

NarfBLAST

Top Post Dawg
Joined
Mar 3, 2002
Location
Waterdown, Ontario, Canada
TDI
2001 Golf 5MT
nicklockard said:
You need to zero out and recalibrate the scangauge. It makes its calculations based on IQ value and the learned adjustments from your tank fill input values.

It should be off wildly since you changed IQ. Don't sweat it. :) Just recalibrate. It may take 3-4 tanks to get back to within +/- 3% accuracy.
Weird, Its been back to normal for a couple of days now... I didn't change anything on the scangauge, but I had disconnected the battery for over an hour to install a CountAct electronic rust inhibiter. At the same time I replaced my air filter and cleaned the snow screen. Now my fuel consumption is down where it used to be... down about 20% from before the work? I thought FOR SURE that my 20% fillup adjustment in scangauge had been cleared by disconnecting the battery, but I checked, its still there along with all the other settings for FuelType (dieselA), and displacement(1.9L)... so that doesn't explain it.

Is there a hidden calibration stored in ScanGuage other than the number you enter when you hit "FillUP"?

I wonder if it is just the warmer weather? Its been sunny and over +15 celcius last couple of days (was closer to freezing last week). I have this crazy theory that perhaps there was this clump of congealed biodiesel stuck in the check valve of my fuel sending unit that maybe melted with the warmer weather. If it were clogged then would the injection pump not have to open the quantity adjuster further to get the same amount of fuel (I notice alot of bubbles in the clear line) and that would explain the higher scangauge readings? I took a peek at my fuel sending unit a few weeks ago after reading some of those threads and I could see how constricted it was in there... anyway, WAY off topic...

Speaking of off topic, should I post more CETANE numbers for Canada here or start a new thread...?
 

nicklockard

Torque Dorque
Joined
Aug 15, 2004
Location
Arizona
TDI
2010 Touareg Tdi w/factory Tow PCKG
Ambient temps have a huge effect on city economy, as it takes so much longer to warm up a colder engine. Also there's winter-versus-summer fuel blending that comes into play and has a rather large effect.

To zero out SGII, just reset everything to factory settings and reprogram your car's settings; but, it's probably better to just wait a few tanks for the new adjustments to kick in. Do a paper/pen calc to verify/check. SG is only as accurate as the information it gets. IQ is factored heavily, but tank fill values drive corrections--it will return to accuracy after a few tanks.
 

NarfBLAST

Top Post Dawg
Joined
Mar 3, 2002
Location
Waterdown, Ontario, Canada
TDI
2001 Golf 5MT
nicklockard said:
Ambient temps have a huge effect on city economy, as it takes so much longer to warm up a colder engine. Also there's winter-versus-summer fuel blending that comes into play and has a rather large effect.

To zero out SGII, just reset everything to factory settings and reprogram your car's settings; but, it's probably better to just wait a few tanks for the new adjustments to kick in. Do a paper/pen calc to verify/check. SG is only as accurate as the information it gets. IQ is factored heavily, but tank fill values drive corrections--it will return to accuracy after a few tanks.
This is mostly highway...will monitor, thanks!

I started a new thread entitled CETANE ratings in Canada Eh? http://forums.tdiclub.com/showthread.php?t=210677
 
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