My MPG seems LOW...

[Prophotog]

2001 TDI Beetle with 5-speed
Since I purchased this about two months ago, I've replaced the glow plugs, fuel filter, air filter and removed the snow box.
I bought this because it seemed everyone I knew or read about was getting OVER 40 miles per gallon.
So far, I've gotten a best of 39.6 MPG and a low of 36.
Now, I do drive between 75 and 80 mph on the way to work, but it's a 74.3 mile commute ONE WAY.
Any help or thoughts would be greatly appreciated.

[pm22071985]

I posted some info on your other thread.

Newbie NB TDI owner....

Keeping your maintenance upto date can also play a part in getting the best mpg & performance.

[FarrisK]

Originally Posted by Prophotog

2001 TDI Beetle with 5-speed
Since I purchased this about two months ago, I've replaced the glow plugs, fuel filter, air filter and removed the snow box.
I bought this because it seemed everyone I knew or read about was getting OVER 40 miles per gallon.
So far, I've gotten a best of 39.6 MPG and a low of 36.
Now, I do drive between 75 and 80 mph on the way to work, but it's a 74.3 mile commute ONE WAY.
Any help or thoughts would be greatly appreciated.

Glow plugs won't do anything, they are just for cold starting.

How many miles are on the rig?

[cep]

Welcome to the low-mpg club. Our '06 TDI has never topped 40 and has gotten as low as 32. FWIW, my 6100 lb Dodge Cummins gets 22.5 empty.

[FarrisK]

Originally Posted by cep

Welcome to the low-mpg club. Our '06 TDI has never topped 40 and has gotten as low as 32. FWIW, my 6100 lb Dodge Cummins gets 22.5 empty.

Yours is a Pumpe Deuse, and those numbers seem about right. The older style TDI should get better numbers.

[CoriBug]

What is your driving style like - do you use cruise control, how do you accelerate and brake? Do you downshift instead of brake sometimes? What about the terrain? Is it mostly flat or hilly? Also, the faster you travel over 60-65 mph, more your MPG decreases.

Your NB should definitely be posting mileage in the 40s. My NB (BEW engine) gets an average of 41, with 50/50 hwy/city.

[Lew]

The Wifes average on her 05 TDI 5 Speed is 47+ MPG on Fuelly.com

[ST1300A]

Originally Posted by cep

Welcome to the low-mpg club. Our '06 TDI has never topped 40 and has gotten as low as 32. FWIW, my 6100 lb Dodge Cummins gets 22.5 empty.

My 2006 w/DSG was getting 43 to 44 in mostly freeway driving when I had the stock wheels and tires on it. Now it gets about 39 to 40 in mostly freeway driving, with Long Beaches and Yoko tires (+1 setup).

[O 16581 72452 5]

It's ridiculous how much bigger rims and wider tires can kill the MPG of TDIs. Are you on stock rims/tires?

[cep]

Originally Posted by O 16581 72452 5

It's ridiculous how much bigger rims and wider tires can kill the MPG of TDIs. Are you on stock rims/tires?

I'm not sure who you're asking, but in my case, yes, our '06 has the stock tires on it. 205-45-17s, I believe.

[O 16581 72452 5]

Originally Posted by cep

I'm not sure who you're asking, but in my case, yes, our '06 has the stock tires on it. 205-45-17s, I believe.

I was asking the OP.

[simonsi]

Originally Posted by ST1300A

My 2006 w/DSG was getting 43 to 44 in mostly freeway driving when I had the stock wheels and tires on it. Now it gets about 39 to 40 in mostly freeway driving, with Long Beaches and Yoko tires (+1 setup).

Check if the rolling radius/circumference (not static) has changed, it maybe a change to the odo is feeding through a small difference.

[Prophotog]

Sorry for the late reply..

162K miles now, 5-speed, stock wheels and tire sizes all around. I bumped my pressures up to 40psi after I replaced the two rear tires.
The terrain, well, it's "hilly" but nothing of a major up-hill downhill grade or anything. Yes, I have a bad habit of downshifting when coming to a stop like I did in my BMW. I try not to rev it past 2500 rpm when upshifting, of course, that all depends on the traffic as I might need to get outta the way and rev it higher.
I recently developed a major shake when braking and a clunking noise from the right front after we had a major snow and ice storm a couple of weeks ago too.
My last two tanks were an average of 38.4 MPG, and I never drive above 75 MPH on my drive to work. It's basically 64 miles on the turnpike and the other 10 on roads with 5 stop-n-go traffic lights/stop signs on the rest.
I was really hoping I'd nail at LEAST a 40 MPG average just in normal driving so I'm wondering if I should do an EGR and Intercooler cleaning along with upgrading the injectors and possibly a chip.....a VAG-COM is definitely in my future too.

[FarrisK]

Originally Posted by Prophotog

162K miles now

That's what I was looking for. Clean out the intake, it's probably NASTY inside.

I bumped my pressures up to 40psi after I replaced the two rear tires.

That'll help, but that's REALLY high (and in my opinion, not safe... nevermind the uneven tire wear.

Yes, I have a bad habit of downshifting when coming to a stop like I did in my BMW.

That's not a bad habit. If the engine is above 1200 RPM (I think that's the right number), and your foot is not on the loud pedal, the engine is not injecting fuel.

I never drive above 75 MPH on my drive to work.

Try staying at about 65, or even 60 for a tank or so. You'll be AMAZED at how much more fuel it takes to maintain that extra 10-15 mph.

[Prophotog]

I started running at 40 psi to see what, if any MPG I might see. I'll probably take them down to factory specs and see if there's any real difference, so far, there hasn't been.
I did find a station near where I work that sells biodiesel, problem is, it's WAY more expensive than regular diesel and of course, there's NO figures telling me what cetane the diesel is.
Anyway, yes, I plan on doing the egr and intake cleaning when it starts warming up. Seems like a TON of work but after reading some posts about it, definitely a worthwile effort.
Thanks for all the info!

[Prophotog]

I yanked off the boost hose the other day and yeah, I think this thing is DUE, make that OVERDUE for an EGR and intake cleaning. I thought about buying the race egr-eliminator but CEL's bug the heck out of me so I think I'm going to do the bypass/screen mod.
Wish me luck!

[05tdi]

People like to talk up their mpg's like their car is superior to everyone else's. Yours is just fine. It all depends on how you drive and weather it's in traffic or not and also at what speeds on the freeway.

[Bo185]

My stock 01 TDI got no less than 40MPG driving 70-75 even with a clogged intake and injection timming off. Dropping the speed to 65 and I got 45-48. I added the 5th gear taller 0.65 overdrive gear. And get no less than 45 MPG at 80!!!

I cleaned intake and removed EGR and added a PCV catch can. I now get noless that 43-45 MPG. Hell I even tow my Polaris 700 with it and still get 45. I have seen 53MPG best ever driving 5 under the speed limit.

How are you figuring you MPG? That can actually effect it most. Fill your tank to top let it settle then top off to top. Clear your trip meter. And drive. When light comes one fill tank to top again. The gals you put in is your total fuel used. Then divide that by the miles on your trip meter. Thats you MPG and its pretty close!

-Cleaning the intake will help!
- Check and adjust timming and change IQ timing via Vagcom. I leaned my out and gain some MPG
-Also slowing will too because the stock OD isn't the best for fast driving. If you insist on 75 mpg get a taller 5th gear it's well worth it.

[kcfoxie]

Hi! Some things I'd suggest:

The clunk you hear is likely the wheel bearing. Get that replaced, infact, I'd go ahead and drop the $ to have the front end rebuilt. Mine made it to 230k but it was also sitting a half inch shorter due to worn out parts... at 160k if it hasn't been done it's time.

PSI plays a role but I'd worry about my suspension hardware being in good shape first before playing with the PSI, just my opinion.

CLEAN THAT INTAKE!! And DO block it off. Software can eliminate that CEL, talk to RocketChip, Unitronic, or any of the other chip vendors (TDIClub.com for reference, note they're heavily biased towards Jeff at Rocketchip).

The B20 is worth the price in regards to the reduction of sooting in the intake and the lubricity it brings back to the Ultra Low Sulphur Diesel. Your injection pump may thank you for it, but then again it may never. I'm a big supporter/believer in Bio and neither of my cars run without at least 10% in them for long periods of time if I can help it. Presently I gave 2.99 for B100 -- thats 9 cents over the D2 or B20 price. Totally worth it since it's made in state with in state crops.

70-80mph with this car will get no better than 46mpg I don't think. Slowing down to 60-65 will bring that up about 7mpg, to close to 53mpg. A software flash, and I base this off a local guy's 2000 TDI that was recently flashed, can add up to 6mpg. I say can because you shouldn't expect that. He was getting 55mpg regularly and after the flash he has had two 60mpg tanks. I don't know how slow he's driving, but I imagine it's pretty slow...

Change all your filters: fuel and air. This makes a big improvement, I actually had a clogged fuel filter so bad I was losing all power in 2nd and 3rd above 3500rpm... it would just sit there and choke and buck.... changed the filter out and now I've got 130mi and I'm not anywhere near the quarter mark on the tank yet.

VENT your tank. Remove the pass. tail light, you'll see the white plastic inside the filler neck... use a flat head to pop the tab free and remove it, press the two tabs on the sides and pull the little device you removed apart and take the spring and switch out then reinstall. This adds about 1.5 gallon capacity to your car, ALWAYS fill to the neck (JUST below that valve -- don't let fuel get into the valve or it'll fill the airsack with diesel fuel). Diesels don't need the airsack bladder but they used the same tanks gas and diesel, the change being to the filler neck. IT's perfectly OK to perm. disable this baldder as the MkV and laters don't have one *at all.*

It takes at least 3 tanks to get a real average. Make your mods and then get 3 tanks under the new belt and do an average calc in a spreadsheet. I think you'll see a big improvement.

[BUGDOUT]

My 99 bone stock 99 beetle with 107k gets a steady 41 42 mpg avg. With a bike rack on top and 75- 80 mph mostly highway mileage and I always down shift. Sometimes its good to drive it hard to blow carbon out of it.