2nd tank 99.5 mk4 tdi

lostinatl

Active member
Joined
Dec 12, 2010
Location
Atlanta
TDI
2010 Golf 4 door, sold 2011 Golf TDI 2 door, sold 99 Jetta TDI
Well, my second fill-up ended up w/my mileage dropping to 37 mpg. After reviewing most of the post here, I realize that the fill-up definitely effects fuel economy. I am doing the vent removal today, but during fill up this time I kept pushing the vent and let the foam die down and I got in quite a bit more diesel. This most likely effected my mpg. I adjusted the tire inflation and now will start to hope for some type of realistic average, but will definitely start to focus on how much goes into the tank.
 

09R/T

Veteran Member
Joined
Feb 10, 2010
Location
Edmonton, Canada
TDI
2006 Jetta 5M
makes a huge difference.....even with the vent guts removed, i can still squeeze in another 1.5 gallons after the pump shuts itself off.....patience is key, mostly due to foaming.

I always fill to the brim, then i know i am never off by more than a few thousanths of a gallon.
 

09R/T

Veteran Member
Joined
Feb 10, 2010
Location
Edmonton, Canada
TDI
2006 Jetta 5M
How much fuel you put in your tank will NOT affect mileage. They are unrelated. Just make sure you consistently fill it ALL the way up
It affects the perceived mileage of the vehicle, if you dont fill it the same everytime, then your perception may be that your mileage is much higher, or much lower than what the car is actually getting.
 

85_305

Banned
Joined
Jun 20, 2010
Location
Buffalo NY/FT Bragg, NC
TDI
1999.5 Jetta 5spd
Exactly. Perception isn't necessarily fact. He was saying that "After reviewing most of the post here, I realize that the fill-up definitely effects fuel economy" and "I am doing the vent removal today, but during fill up this time I kept pushing the vent and let the foam die down and I got in quite a bit more diesel. This most likely effected my mpg". The amount of fuel he puts in wont affect economy; but he DOES need to fill it up to the same point every time to keep accurate measurements of economy.
 

pnubble

New member
Joined
Dec 19, 2010
Location
Maine
TDI
2003 GLS Jetta TDI
48 mpg

I've only had my TDI Jetta for three weeks and I went from 44MPG to 48MPG by just increasing the PSI in the tires. I'm looking forward to the first tank w/ 50MPG. By the way deisel in southern Maine is $3.489/gallon.
 

lostinatl

Active member
Joined
Dec 12, 2010
Location
Atlanta
TDI
2010 Golf 4 door, sold 2011 Golf TDI 2 door, sold 99 Jetta TDI
Not sure how you can say that my fill up will not effect my mileage? If you use the basis: 400 miles / 15 gallons = 26.667 mpg
400 miles / 16 gallons = 25 mpg and 400 / 14 = 28.571

Unless you are checking your mileage a different way how much you put in will definitely effect your mileage. Or am I just missing something completely? I did do the vent, it took 5 minutes. Anyone who hasn't done it in the Atl area or is nervous, I can meet you and give you a hand. Just send a PM.
 

85_305

Banned
Joined
Jun 20, 2010
Location
Buffalo NY/FT Bragg, NC
TDI
1999.5 Jetta 5spd
Not sure how you can say that my fill up will not effect my mileage? If you use the basis: 400 miles / 15 gallons = 26.667 mpg
400 miles / 16 gallons = 25 mpg and 400 / 14 = 28.571

Unless you are checking your mileage a different way how much you put in will definitely effect your mileage. Or am I just missing something completely? I did do the vent, it took 5 minutes. Anyone who hasn't done it in the Atl area or is nervous, I can meet you and give you a hand. Just send a PM.
Dude. It doesn't affect your damn mileage. If anything, more fuel will allow you to go FURTHER. But it wont 'affect your mileage'.

Why the f*ck would you keep going the same amount of miles while putting more fuel in? Thats asinine. How old are you? Because if your a kid I'll stop being an a$$hole but comeon seriously.. you wont be going the same amount of miles if you put more fuel in.

Your ideology of how fuel/distance work is all tangled up. The amount of distance you go is dependent upon how much fuel is available. The way your thinking is more will still equate to the same amount of miles traveled.
 

smck

Veteran Member
Joined
Mar 27, 2008
Location
south east indiana
TDI
2000 golf man, 2003 golf man
Take it easy on the new guy. I assume he is smart enough to know that his calculation was affected because he filled the tank more completely this time. Keep on it lost one you should easily be able to get 50's as should anyone with an alh manual.
 
Last edited:

IanMH

Well-known member
Joined
Feb 8, 2010
Location
USA
TDI
'01 Jetta ALH TDI 5 spd ~207k PP768, T4s, Pelquin, .658 5th, 17/22 ~25psi, EJ SMIC, RC4+ '00 Jetta ALH TDI 5 spd ~217k PP520s, '06 BRM DSG RC1+ Stg2 Cam
I think I should be checking the air in my tires!
 

lostinatl

Active member
Joined
Dec 12, 2010
Location
Atlanta
TDI
2010 Golf 4 door, sold 2011 Golf TDI 2 door, sold 99 Jetta TDI
Yea, your a genius 85 305. Do you understand how formulas work. It was an example. Genius.
 

85_305

Banned
Joined
Jun 20, 2010
Location
Buffalo NY/FT Bragg, NC
TDI
1999.5 Jetta 5spd
An example? Telling me that your economy is going to go down putting more fuel in, and that you will STILL only get 400 miles per tank even with more fuel, is ignorance. Not a formula.
 

raikky

Veteran Member
Joined
Aug 20, 2010
Location
England, Sheffield
TDI
vw polo 1.4 tdi se pd
when i fill up i use the same station, the same pump every time usualy once per month. i just fill till it clicks. calculating my mpg 100 percent accuracy prob not. care? not really. you can get too obsessed with fuel economy. this venting thing sounds alright if i was filling up and the nearest pump from the one im filling up with is about 800 miles in which case id need the extra diesel. but thats about it
 

flatlanded

Veteran Member
Joined
Aug 1, 2009
Location
Saskatchewan
TDI
2002 Jetta
To be completely honest and neutral... you do get better fuel economy with an emptier tank due to the loss of weight. The results are negligible but still results none the less.

It is best to do economy calculations by filling up several times and using the average. One or two litres +/- on a fill up will make a difference from tank to tank basis.

37 is a little low unless you've been doing some stop and go city driving where accelerator is an on/off switch ;).
 

lostinatl

Active member
Joined
Dec 12, 2010
Location
Atlanta
TDI
2010 Golf 4 door, sold 2011 Golf TDI 2 door, sold 99 Jetta TDI
My point was lost on 85 305. Try decaf. I was talking about the fact that unless you have an accurate fill-up...hence, why I stated that AFTER I do the vent removal, I should be able to get more accurate figures. Yes, try decaf, take a nap or change your tamp**
 

85_305

Banned
Joined
Jun 20, 2010
Location
Buffalo NY/FT Bragg, NC
TDI
1999.5 Jetta 5spd
Yes, I guess your point was in fact lost with me. MY point is, your mileage isn't going to differ putting more fuel into your tank. Instead, your travel range will increase. Thats all I'm saying. If I misinterpreted you, my apologies.
 
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