New member here, have a 2005 TDI NB

[Bug-Tamer]

Glad to have found this site. Have a 1000 questions.

Around 13,000 on it aleady. Noticed a change in the MPG's recently. Have got up 600 gallons to the tank, but lately I'm lucky to get 500. What gives?

Do run the air and have trouble keeping my foot out of it on back country roads

I drive 50 miles a day, so it pays for itself.

[iScott]

Hey! Welcome to the Org!

[Breez]

First off welcome!!!

Second, did it get its 10,000 mile tune up/oil change at the dealership/mechanic? Have you done anything unsual, like fill up at a different station, change your driving style (take a road trip etc)...

...Have you considered adding an additive to your deisel?

Since its the Beetle is so new (aka warranty) I would go to a dealership if you start feeling concerned about the MPG... or at least give them a call

Hope that helps

[Whitacre]

Hey welcome to the ORG!

The feet into the accel pedal is always a wonderful MPG killer. I actually had the total opposite.
I was getting about 500 a tank, and all of a sudden i am getting a wondeful up in mileage this tank. I changed my driving habits from being a little spirited to being an Oregonian Do you vent?

And already i notice a huge difference. If its getting bad, check your MAF, or perhaps floor it for a few secods to clear out any soot. Otherwise what about tune ups? Everything done on time and in good standing?

Again welcome. You will love it here!

[SPIRU]

Welcome to da org!

[jpdeuce]

Do you vent, or do you know what venting is?

Just inside your fuel fill neck you will see a little tube on the side. You can push that tube down to get more fuel in the tank. Or you can remove it completely.

This will not explain getting less miles per tank currently...but until you have a consistent place to top off to when you fill up...you really can't compare tank to tank. Since diesel foams up and different tanks shut off at different points, you never know if you are filling all the way up. Speaking of, do you know diesel foams? If you wait after the first shut off point for a minute or so and then start filling up slowly, you will be able to fit much more fuel in the tank.

I removed the vent on my Beetle and I fill up until I see fuel almost about to come out. I do it the same way everytime, so I know exactly how much fuel is in there. Until you do this you want be able to compare tank to tank with much certainty.

[jpdeuce]

BTW - welcome to the Org!

You are also still in the break in period. Do a search here or on TDIclub to find how you should be driving. But you should be noticing an increase in fuel mileage until about 50K miles.

With 15K miles you shouldn't have an MAF problem...but who knows. Make sure you are getting the right oil in your TDI at oil changes. At this point I think you should have had 1 at 5K miles...maybe another 10K, is that right? From then on it should be 10K mile OCIs (oil change intervals).

Also, make sure your tire pressure is up. I run all 4 at 40 psi. This is a little harder than others run...but I also average 46 mpgs over the last 25K miles or so and get 700 miles on every tank.

[Dorado]

Welcome and congrats on your NB TDI!

Diesel fuel quality will affect milage and smoke, so try to find the best stuff in your area (high cetane, lower sulfur), and check out the forum at tdiclub.com (if you already haven't)... for all the info you need.

[Dick_Larimore]

Factors that can affect (reduce) diesel fuel mileage include:

• Tire pressure (too low)
• Emergency brake or brake pads dragging
• Reduced intake air (clogged snow screen or air filter)
• Addition of a roof rack or other item to increase drag
• Defective MAF (mass air flow) sensor
• Unusually poor diesel fuel quality
• Front wheels out of alignment
• Change to wider, lower profile tires
• Intake clogging
• Change in driving habits (more stop and go traffic)
• Clogged exhaust system (muffler, catalytic converter, etc)
• Coolant temp sensor defective (under reporting coolant temp)