My worst tank

lildevildee

Veteran Member
Joined
Oct 8, 2003
Location
Knotts Island, NC
TDI
2012 Jetta w/6spd manual
I knew this would be a bad tank for me; less than 20 miles on the highway with the rest in-town kills the fuel economy. My fuel light came on at 480 miles. I filled up today at 499.6 miles with 14.15 gallons for a whopping 35.307mpg. It's the first time I've broke less than 36mpg (not counting the fuel filter change tank.)

On a more positive note, there's a new bio pump (4 actually!) less than 10 miles from my home. WOOHOO!!!
 

whitedog

Veteran Member
Joined
Jul 12, 2004
Location
Bend, Oregon
TDI
2004 Jetta that I fill by myself
My last tank estimated out at about 35 as well. I put some Highway Star miles on this tank and hit about 42.5. If I take my Seester to Alabama next month I'm going to have my summer tires on. 55 MPG here I come. 57 if she drives.
 

Tim Birney

Veteran Member
Joined
Dec 14, 2005
Location
Dearborn Heights, MI
TDI
05.5 TDI
I have been running 30 to 32 all winter (city driving).
Last weekend we had two days in the High 60's, and I filled up, reset all counters and made a short test of 100 miles Highway, and 42 miles city.

Googley Moogley!!!!!! 45.2 mpg (MFI said 45.5)

This summer looks very promising.
 

lildevildee

Veteran Member
Joined
Oct 8, 2003
Location
Knotts Island, NC
TDI
2012 Jetta w/6spd manual
Ouch Tim. 30-32mpg? And here I'm complaining about 35mpg, lol.

I did run 63 miles tonight; MFI indicated 50.3mpg. When I'm running bio, it's pretty much spot on. Wish I could stay at that 50 for the next 500 miles!
 

whitedog

Veteran Member
Joined
Jul 12, 2004
Location
Bend, Oregon
TDI
2004 Jetta that I fill by myself
lildevildee said:
Ouch Tim. 30-32mpg? And here I'm complaining about 35mpg, lol.

I did run 63 miles tonight; MFI indicated 50.3mpg. When I'm running bio, it's pretty much spot on. Wish I could stay at that 50 for the next 500 miles!
HUH??? I'm not getting 30-32????

Oh. wrong guy.

Good news is that I MAY be getting a Banjo on my knee so I should see some good numbers for that.
 

Mach1

Vendor , w/Business number
Joined
Sep 27, 2005
Location
Spicewood, Tx.
TDI
05.5 Jetta 5 spd, 06 Jetta DE DSG, 04 F250 6L, 2000 F250 7.3L
Last tank, I got 44mpg, I had to use the AC a little, damn 95 degree days already!!! I believe we are done with the winter blend down here..
 

Tim Birney

Veteran Member
Joined
Dec 14, 2005
Location
Dearborn Heights, MI
TDI
05.5 TDI
lildevildee said:
Ouch Tim. 30-32mpg? And here I'm complaining about 35mpg, lol.

I did run 63 miles tonight; MFI indicated 50.3mpg. When I'm running bio, it's pretty much spot on. Wish I could stay at that 50 for the next 500 miles!
That is just what you could expect when the temps are below 30, mixed with winter fuel.
Over the last 7 days or so, we've been in the high 30's, and my city mileage is right at 34 (MFI), so I am not too worried about the MPGs.
When the weather breaks, and I do my 10K oil change w/ELF 506, I expect to break 50 mpg on the highway (that is ACTUAL 50 mpg, not MFI)
 

Losha

Veteran Member
Joined
Mar 8, 2005
Location
Sioux Falls, SD
TDI
06 Jetta TDI DSG, 2001 Golf TDI, Audi S6, A8, Toureg
whitedog said:
HUH??? I'm not getting 30-32????

Oh. wrong guy.

Good news is that I MAY be getting a Banjo on my knee so I should see some good numbers for that.
30-32mpg is that bad last thank I had 25mpg wiht retarded timing, but it was snowing, and driving hard. My best fuel economy I had was last spring 45mpg.
 

Mach1

Vendor , w/Business number
Joined
Sep 27, 2005
Location
Spicewood, Tx.
TDI
05.5 Jetta 5 spd, 06 Jetta DE DSG, 04 F250 6L, 2000 F250 7.3L
You people take a beating on your winter fuel, worst then my summer AC maximus usage..
 

TonyJetta

Top Post Dawg
Joined
Sep 15, 2005
Location
Tucson, Az
TDI
'15 Jetta TDI SE / '06 Jetta TDI DSG Pkg0 / '96 Passat TDI
We are getting consistent 38-39, with the wife freeway (traffic) driving.

If I can get it on the road to Tucson & back (~250mi), I can get 41.5. I think if I can get on the road for 500-1000 to burn some fuel, I could get 42-45 or more.

Tony
 

TerryTDI

Well-known member
Joined
Aug 26, 2004
Location
Muskego, WI, USA
TDI
1997 Jetta TDI
My mileage has been in the 30s as well all winter. I bought the 2006 Jetta in December so I have yet to see its true potential in the mpg area.
 

fish_on

Well-known member
Joined
Jun 21, 2005
Location
Columbia City, OR
TDI
2010 Jetta, White, DSG
WOW I thought it was bad when I only got 42. Most of the time I average 46-47, but I commute 300 miles/day @80mph.
 

Vindiesel6

Veteran Member
Joined
Jul 14, 2003
Location
Northern, NJ
TDI
2002 VW Golf GLS TDI & 2015 Q5 TDI
I saw my worst mileage last tank. My 2002 tdi only achieved 400 miles before the light came on, about 32 mpg. I think it was due to an oil leak from my turbo seals. My elephant hose ccv mod caused the crank case to become pressurized when it froze up this winter causing my turbo seals to leak / blow out. This put about a quart of oil in my IC. I just had the turbo replaced under warrantee so we shall see if my mileage goes back up or if there is another seal in the engine that is leaking. Usually I can reach at least 500 miles on a tank before the light comes on.
 

Tim Birney

Veteran Member
Joined
Dec 14, 2005
Location
Dearborn Heights, MI
TDI
05.5 TDI
TerryTDI said:
My mileage has been in the 30s as well all winter. I bought the 2006 Jetta in December so I have yet to see its true potential in the mpg area.
Wisconsin, S. Dakota, Michigan...
Trust me, when we get up above 40 F, and get summer fuel, the MPGs will return with a vengeance.

;)
 

DieselDavid

Veteran Member
Joined
Sep 6, 2005
Location
Maryland
TDI
2014 Jetta TDI 6M, 2015 Passat SE TDI 6M, 2015 Golf SEL TDI DSG
My last 10 tank fulls were between 27 Nov 2005 and 22 Mar 2006. 1 average was "low" at 38.9 MPG (on 22 Jan 2006). That was my worst fuel economy so far. The other 9 averages ranged between 43.67 and 46.74 MPG.

When I add the mileages and the gallons from those last 10 tank fulls and then divide, my "rolling average" comes out to 44.63 MPG. 5700.1 miles and 127.71 gallons.

Most of my mileage is commuting between home and work. It is mostly highway driving in the mornings, traffic is fairly light, and my speeds are fairly constant. In the afternoons traffic is usually bad - inconsistent speeds and I tend to not use the highways. I don't use the cruise control that often. Maybe once every 10 to 15 miles I downshift and floor the accelerator to blow out soot.

The diesel fuel I use is rated at 40 cetane and I add 5 fluid ounces of Power Service seconds before filling up each time. Yes I know we are supposed to be using 45 cetane but I can't seem to locate it in my area. The other significant thing to mention is my tires are slightly overinflated at 37 PSI.
 

DRbillZ

Veteran Member
Joined
Mar 17, 2003
Location
Jackson,Tn. Home of Carl Perkins :)
TDI
New Beetle, Jetta, one totaled Passat....RIP.
I run my Beetle's tires at 44 psi. I can coast forever with the clutch in :) . So it is possible to run them fairly high.
Tires have worn evenly the whole 45,000 miles they have been on and it does not slip in water, rain or snow.
It is time for new ones and I will get the Conti Extreme Contact tires again and will probably get them for the Jetta when the stock tires wear out.
 

Vindiesel6

Veteran Member
Joined
Jul 14, 2003
Location
Northern, NJ
TDI
2002 VW Golf GLS TDI & 2015 Q5 TDI
I have the Continental Extreme contact tires on my golf TDI currently. I do not like them at all. I will not be buying them again and would not recommend them to anyone.
 

whitedog

Veteran Member
Joined
Jul 12, 2004
Location
Bend, Oregon
TDI
2004 Jetta that I fill by myself
Vindiesel6 said:
I have the Continental Extreme contact tires on my golf TDI currently. I do not like them at all. I will not be buying them again and would not recommend them to anyone.
Why? I don't know enough about car tires, so try to educate me, please.

I am asking the same question to DRbillZ.
 

quartermeter1999

Veteran Member
Joined
Sep 1, 2005
Location
Huntsville Ala
TDI
2006
What transmission are some of you running and getting <40 mpg??

I've got a 5speed and drive 75% highway at 60-90 mph. I haven't gotten < 44 mpg yet and 48 a few times. Thats with no air on and coasting in neutral when I can.

I think neutral coasting is best when you have a long down hill run. I can accelerate alot in neutral and not as much in 5th gear.

Could that be the reason?

One doen hill run I drive weekly I go from 60 to 95 and back to 60 in a 3-4 mile down hill run. In 5th I start at 60 mph and only get up to 80 and I'm back to 60 sooner.

That's documented proof.

Also tire pressure is at about 40-42 psig and
thats pencil and paper figures...Mine's a Pkg 1 with no mpg computer.


QM out............
 

mobe

Veteran Member
Joined
Feb 10, 2002
Location
Orion Spur
TDI
Golf
quartermeter1999 said:
Thats with no air on and coasting in neutral when I can.

I think neutral coasting is best when you have a long down hill run. I can accelerate alot in neutral and not as much in 5th gear.

Could that be the reason?

QM out............
Nope, you burn fuel when coasting in neutral, you burn no fuel when coasting in gear. Doesn't sound right but it's true.

Any hill you coast down regularly is one you drive up regularly. Friction says you will never break even. Sorry.

You're getting better than average mpg. Better than me anyway. Be Happy!:)

Deisha, if you're still reading this, do you think the Nokians are hurting your MPG? How do you like them? Thanks.:)

-Matt
 
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lildevildee

Veteran Member
Joined
Oct 8, 2003
Location
Knotts Island, NC
TDI
2012 Jetta w/6spd manual
It's hard to say if the Nokians killed some of the fuel economy; I put them on in December and haven't had many miles on them yet. This summer might be a better comparison but then I'll be a little more (lot more!) broken in than last summer.

My last tank was 43.63 mpg; that was running a bio-blend and mostly highway miles.

I love the Nokians; even if I suffered a mpg loss with them, they are still very worth it. They actually keep my car on the road during our wet season :) I'd def. buy another set of Nokians for the Jetta and will be getting some WRs for the Eurovan this fall.
 

quartermeter1999

Veteran Member
Joined
Sep 1, 2005
Location
Huntsville Ala
TDI
2006
mobe said:
Nope, you burn fuel when coasting in neutral, you burn no fuel when coasting in gear. Doesn't sound right but it's true.

Any hill you coast down regularly is one you drive up regularly. Friction says you will never break even. Sorry.

You're getting better than average mpg. Better than me anyway. Be Happy!:)

Deisha, if you're still reading this, do you think the Nokians are hurting your MPG? How do you like them? Thanks.:)

-Matt
Yes that is true But.

The car should use very little gas ideling in neutral.

It will reach a higher speed in neutral and therefore coast a greater distance.

To reach the same distance coasting in gear you have to give the car gas to reach the same spot you would have reached in neutral ideling.

I believe It will use more gas giving it gas to reach that distance than it would have coasted.

No way to prove it unless you put flow meters on your gas lines.

But I am getting good mileage 44-48.........SOOO....

Try it and see if it helps your mileage.

Both are just theorys....Neither proven......

All the computer mpg is giving you is what you are getting while you are coasting. When you give it gas to get back up to speed your mpg goes back down. That is the difference.

QM out..............
 
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quartermeter1999

Veteran Member
Joined
Sep 1, 2005
Location
Huntsville Ala
TDI
2006
Well on my last tank I coasted in gear and got <44 mpg. I'll do it on the next few tankfulls and see what happens.

coasting in neutral I have gotten 44-46 mph usually. I did get less than 44, 2 other times coasting in neutral.

I'll keep trying this in gear and check my mileage a few more times to compare.

Coasting In gear really holds the engine back and it doesn't want to get over 60-70 mph on long runs. On the same long down hill runs I can get up to and over 90 in neutral.

I'll experiment with it and see what happens.

Great site.......

QM out...........
 
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