MK6 Quest for 900+ mile tank

993er

Veteran Member
Joined
Oct 10, 2013
Location
Canada
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None
Ok, time to start documenting this so folks can follow along.
Impressive, but I have a few questions.

You are getting 61.3 MPG (US), so that would be 73.6 MPG (IMP) or 3.84 L/100 KM out of a box stock 2.0L TDI engine.

Under what conditions, speed, temperature, zero wind, etc did you get that level of fuel efficiency?

I take it this was a non-stop 900+ mile run on a level Interstate highway?
Standard tire pressures?

Let us in on the secret.
 

Savageman69

Top Post Dawg
Joined
Aug 3, 2007
Location
ontario
TDI
2012 Highline Touareg TDI
Not bad for a mk6.
whats that mean exactly?....Are we going to come back to trying to compare it to a 90hp, less weight, smaller car again?....The fact that my car dynoed at over double the hp of a alh and i can still reel in 60us mpg i think thats good...not just good for a mk6
 

Scoutx

Veteran Member
Joined
Jun 4, 2012
Location
Virginia
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2012 Jetta (6MT) - 1000 Mile Club (retired)___ 2015 Jetta SEL (6MT)
Scoutx, what size tires are you running?

And congrats on the 1K mile mark! Very impressive indeed!
Still on the OEM Hankook stock tires and I was running at 42psi.

Oh, and standard 17"
 
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Scoutx

Veteran Member
Joined
Jun 4, 2012
Location
Virginia
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2012 Jetta (6MT) - 1000 Mile Club (retired)___ 2015 Jetta SEL (6MT)
This is great. Congrats to everyone.

How far are you guys running past the 0 miles to empty mark? I have ran 10 miles past and I was very nervous doing so... I noticed recently that the 0 DTE will come one before the last 1/16 bar on the tank goes away. It may take another 5 miles or so for that to dissapear.
DTE went to zero at 978.3 miles
Gauge went to zero at 982.9 miles
Final at fill-up was 1000.5 miles

So 22.2 miles after DTE to zero and 17.6 miles after gauge went to zero.
Not sure how much useable fuel was left, but it couldn't have been much. Though someday I want to put the Mk6 vent mod in and if I can I want to run it exactly to zero and then run the pump until I start getting air just to see how much actually is left.

Are you always manually topping off your tank? I purchase gas in a state where law mandates full service so I never fill past the first stop. The most I have gotten into a tank was 14.316 gallons. I am not sure how much more I can push the the tank.
If you're not venting then 14.3 is probably about right what with foaming and all. I do typically vent unless I know I'm going to immediately park. Doing that can push your fill from empty to around 15.2 without anything else other than waiting for the foam to settle and trickling in the fuel to the lip. However, you need to run about 10 miles before parking less expansion causes fuel to start weeping past the cap and spilling on the ground.


Does the tire pressure seem to be more effective? I'm curious to try changing that alone and see what difference I get without changing any driving habbits.
It has an effect, but it also impacts the smoothness of the ride. Not normally a real issue for interstate driving, but it makes the ride harsh and any imperfections in the road surface much more pronounced. Generally I run about 36psi, unless I know I'm going long haul then I will boost the pressure to around 40-42psi. Once we get into ice and snow I drop the pressure back down to 32psi to insure maximum grip. The higher pressures won't do as much in city driving, but during extended highway runs the higher pressures will make themselves felt as you watch your average mpg numbers increase.
 

Scoutx

Veteran Member
Joined
Jun 4, 2012
Location
Virginia
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2012 Jetta (6MT) - 1000 Mile Club (retired)___ 2015 Jetta SEL (6MT)
Impressive, but I have a few questions.

You are getting 61.3 MPG (US), so that would be 73.6 MPG (IMP) or 3.84 L/100 KM out of a box stock 2.0L TDI engine.

Under what conditions, speed, temperature, zero wind, etc did you get that level of fuel efficiency?

I take it this was a non-stop 900+ mile run on a level Interstate highway?
Standard tire pressures?

Let us in on the secret.
Mostly interstate from around C'ville Va, to Richmond VA, but various side trips to other locations. The bulk of the trips were pretty much my normal day to day driving, but I did extend my runs towards the end to help wrap up the tank and avoid the forecast of rain which would have killed my numbers. Interstate speed was normally held at 55mph, temperatures were around the mid 80's. No AC use. No strong winds, but light winds were common. This does include one drip over the mountains to Fishersville and back, so it wasn't all flat ground, but that run actually resulted in a personal best according to the dream gauge. So, no it wasn't non-stop and tire pressures were held at 42 psi. If I could have run a straight run with one or two stops and conditions held, I feel an 1,100 mile tank could have been possible. At times the combination of distance covered and the dream gauge's assertion of remaining distance would place me over 1,200. Needless to say, I was using every trick I knew of to squeeze as much as I could from each drop. My expectation was to hit 900 miles, and possibly a few busted runs in there before the stars aligned. The 1000 miles I got was NOT what I was initially shooting for, but as the numbers continued to climb, it became a possibility, then a real possibility, but one bad run, one accident on the interstate, almost anything would have ended it. I filled at 1000.5 and I seriously doubt if I had much more than 10 miles remaining before running dry. Without the city driving I did, the cold starts, and so on, I think another 100 could be squeezed out, but probably not enough for another 200. Of course with long runs like that fatigue starts to become an issue and you lose mileage due to driver error.
 
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993er

Veteran Member
Joined
Oct 10, 2013
Location
Canada
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None
So, no it wasn't non-stop and tire pressures were held at 42 psi.
That is high considering 33 psi is posted on the label.

I'll have to give it a try next summer to see if I can get into the 50 MPG (US) range using a normal fill method. Doing 55 MPH will be tough. I'm getting 45 MPG (US) while cruising at a steady 72 MPH (90% of the tank was highway).
 

SirSipsAbit

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May 28, 2012
Location
North woods
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2012 Jetta TDi
That is high considering 33 psi is posted on the label.

I'll have to give it a try next summer to see if I can get into the 50 MPG (US) range using a normal fill method. Doing 55 MPH will be tough. I'm getting 45 MPG (US) while cruising at a steady 72 MPH (90% of the tank was highway).
My 920 mile tank was with my tires at 48psi.... Tire pressure is uber important for a good run!
 

Scoutx

Veteran Member
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Jun 4, 2012
Location
Virginia
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2012 Jetta (6MT) - 1000 Mile Club (retired)___ 2015 Jetta SEL (6MT)
Just be aware that your ride will get harsher, and you will lose some grip particularly in wet/snowy/icy conditions. Also conditions and weather matter. In NY at this time of year, you're probably not going to have much luck getting 50mpg.

1) You are certainly into Winter Blend at this point, which has less BTUs per gallon, and thus lower fuel economy potential

2) Cold weather also significantly reduces your fuel economy potential

That said, you should still see an improvement, but since it's a percentage increase of your average mpg, it will be less drastic numberwise than what it might be during the spring, summer, or fall.

Also remember that what you do off the interstate can be even more important than what you do on the interstate. If you drive 5 miles with an average of 30mpg...it's going to take a lot of interstate driving over 50mpg to pull up your average to above 50mpg. Generally, you're only going to post above 50mpg in a Mk6 during the spring, fall, and possibly summer (depending on AC use).

For example last year my average between Sept and March (inclusive) was below 50mpg, and only in the spring and fall can I consistently post averages above 50mpg. In the Summer, AC use will shave off enough to drop me below 50. Even though I'm often only running the AC one way on my commute.
 
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MAXecutive

Well-known member
Joined
Oct 1, 2011
Location
New York
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Jetta VI
Yes, I definately noticed that pattern. The off interstate driving is what really kills me because the car is usually cold and it a lot of uphill stop and go traffic.

I didn't try the tire pressure modification yet however I decided to try a DIY winter cover. With my luck, its 65 degrees with rain in NY today but temperatures will drop drastically soon again.

With the fuel, the "winter blends" are designated by season and location? I guess I do not have a choice of what I am buying?
 

993er

Veteran Member
Joined
Oct 10, 2013
Location
Canada
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None
What really matters to me are the MPGs or the L/100 Km.

Going further on a tank is a function of MPGs, but also so many other factors, some you can control and some you can't for an apples to apples comparison.
 

Scoutx

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Jun 4, 2012
Location
Virginia
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2012 Jetta (6MT) - 1000 Mile Club (retired)___ 2015 Jetta SEL (6MT)
Absolutely, only some of the variables are under your control. Weather, is a significant factor and generally you're going to drive in whatever weather you have at the time. Such as rain, which is also a killer for high mpg.

Others such as throttle control, tire pressure and so on are under your control.

Others are only somewhat under your control such as moderating or eliminating the need to stop fully or how much you brake.

Not every driving situation allows you to post big numbers. All you can do is improve upon what you have. Just remember it's not worth it to wreck your car, or get a ticket, or otherwise ruin your day simply to try and save 1/2 gallon of fuel. So moderation and common sense are the ticket.....usually.

With the fuel, the "winter blends" are designated by season and location? I guess I do not have a choice of what I am buying?
Yes, other than the deep south, stations adjust the blend to produce fuel which won't gel up as the weather gets colder. The normal manner in which this is done (cutting D1 with your standard D2) lowers the BTU per gallon, thus you need more fuel to get the same energy. And let me take a moment to suggest anytime you're going to travel far north, or temperatures are going to drop drastically below normal during the winter, it's well worth putting some anti-gel additive in your tank and running the car long enough to distribute it through the fuel system. Once the system gels up....it's a headache at best, and at worst you're stuck out on the road someplace in the middle of a winter storm. Cheap insurance, and IMO well worth the price for the few times it should be necessary to avoid such a risk.
 
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