Is 35MPG normal for a TDI?

[stinkbelly]

This is my first post so please be kind. I bought a 2006 TDI beetle a month ago and I am consistently getting 35mpg. I am wondering if this is normal. I have tried 80mph, 65mph, and 71mph and all got 35mpg. What can I do to increase the gas mileage or is this what I should expect.

[Smileybug]

What transmission is in the car? 35mph seems a bit low, but if its an auto, it could be not too far off.

[stinkbelly]

It is an auto transmission.

[Smileybug]

Also, are you calculating based on how many miles traveled divided by gallons put in the car?

[stinkbelly]

Yes, I am dividing the miles driven my the gallons of fuel to fill it up.

Would the auto get better gas mileage if I used the stick shift option. Honestly I don't know what that is or how to use it.

[lightflyer1]

The auto (DSG) transmission gets almost as good as the manual as far as economy goes. More important is how it is driven. Read here and practice all you can incorporate into your daily drive.

Home

There are other sites as well. I get about 36 mpg in my 2005 NB 5 speed around town.

[SMG]

I get 40-47 MPG out of my 5-speed depending on the time of year. 47 MPG is my best summer tank so far, 1100kms on one tank.

[h_2_o]

i hate to disagree with a previous poster but i have never seen the auto get near the mileage that the manual gets. 35 seems a bit low imho.

also how much city/highway driving is done? if most is city then 35 might be right for the auto.

[Rubee2006Tdi]

How many miles on the Tdi? My 2006 runs between 37-44 depending on speeds. I can run 80+ for long stretches and mileage drops to low end. 60 mph nets the higher figures. Mine has the DSG transmission. Perhaps your NB is ready for service? Just an idea.

[stinkbelly]

90% of my driving is highway. When I first bought it, I drove straight highway fo 2.5 hours home and as soon as I exited the highway I filled it up again to check gas mileage.

My beetle has 61,000 miles. It is new to me. I don't know what service has been done to it before I bought it. I have changed oil and air filters, but that is it.

Is there other service I should consider to increase gas mileage?

I use my cruise control almost all the time. This may not be the best idea because I drive through some large hills daily.

I also have my AC blowing at full blast most of the time. We are on our 18th consecutive day of 100+ degree weather here in Texas.

[lightflyer1]

Originally Posted by h_2_o

i hate to disagree with a previous poster but i have never seen the auto get near the mileage that the manual gets. 35 seems a bit low imho.

also how much city/highway driving is done? if most is city then 35 might be right for the auto.

How much experience do you have with the DSG transmission? It isn't the same as the old autos and has no losses due to a torque converter. The previous auto transmissions 2003 and earlier, I would agree with you. The DSG being a computer shifted manual transmission is different.

[Rubee2006Tdi]

The DSG tranny is incredible BUT it requires service at 40K. Not cheap either (300-400). If there is any way to find out if this was done it might be a good thing. VW is adamant about this service being necessary. And last I knew a new DSG could run up to 8 grand. I don't know if this would affect your mpgs but who knows?

The fuel filter is the only other thing that should have been replaced. I think at around 20K or so. Perhaps the filter is not doing its job? Good luck.

[taplb]

I get about 36 with in town driving. Normally i get 40 mpg. Have gotten as high as 45.31 mpg. Mine is also an automatic.

[h_2_o]

i've done a fair amount with all of vw's auto trans in the mk3 and mk4 platforms and IMHO they all give less than their manual counterparts, but that is from personal experience with them.

anyway back to the op's question about their personal mileage. couple more questions and something you said. let's assume that initially you should get 42 mpg with the air use let's take that down to 40 which is not unreasonable. now you are looking at a possible 5 mpg difference in what you probably should be getting. How is your highway driving, with the auto's i've personally dealt with if you start going above ~70 to ~75 depending on the vehicle the mileage starts to drop. you say you have tried all speeds and they all result the same. are you doing this from fillup to fillup or trying all these speeds and going off one of the computers rated mpg? next is weight, no i'm not calling you a fatty, but how much besides yourself is in the car when you drive? an additional 3 passengers on the trips or passenger and a loaded up cargo area can cause problems as well. Next Wheels, are they stock or did someone go with larger wheels that weigh more. Sounds silly but the reading over on tdiclub the guys over there have some interesting numbers on heavier wheels. Also Elevation are you at? Higher elevation i would believe would run cause a slight decrease in mpg. Along with the elevation, how is the terrain where you are at? if you are going up and down mountains etc.... then that as well will cause variations. Also forgot did you check your tire pressure is that correct? running low can decrease your mileage.

so with those variables to consider it might be perfectly normal to get the mileage that you are currently getting.

On a different note, do you know anyone with a vag-com that can do some measuring block reading for you? If you do have them run a log on your maf to see how it is doing, a bad maf can cause problems as well. Also how many miles are on your car?

go ahead grammar/paragraph/etc.... nazi's blast away i don't care.

[stinkbelly]

Originally Posted by h_2_o

i've done a fair amount with all of vw's auto trans in the mk3 and mk4 platforms and IMHO they all give less than their manual counterparts, but that is from personal experience with them.

anyway back to the op's question about their personal mileage. couple more questions and something you said. let's assume that initially you should get 42 mpg with the air use let's take that down to 40 which is not unreasonable. now you are looking at a possible 5 mpg difference in what you probably should be getting. How is your highway driving, with the auto's i've personally dealt with if you start going above ~70 to ~75 depending on the vehicle the mileage starts to drop. you say you have tried all speeds and they all result the same. are you doing this from fillup to fillup or trying all these speeds and going off one of the computers rated mpg? next is weight, no i'm not calling you a fatty, but how much besides yourself is in the car when you drive? an additional 3 passengers on the trips or passenger and a loaded up cargo area can cause problems as well. Next Wheels, are they stock or did someone go with larger wheels that weigh more. Sounds silly but the reading over on tdiclub the guys over there have some interesting numbers on heavier wheels. Also Elevation are you at? Higher elevation i would believe would run cause a slight decrease in mpg. Along with the elevation, how is the terrain where you are at? if you are going up and down mountains etc.... then that as well will cause variations. Also forgot did you check your tire pressure is that correct? running low can decrease your mileage.

so with those variables to consider it might be perfectly normal to get the mileage that you are currently getting.

On a different note, do you know anyone with a vag-com that can do some measuring block reading for you? If you do have them run a log on your maf to see how it is doing, a bad maf can cause problems as well. Also how many miles are on your car?

go ahead grammar/paragraph/etc.... nazi's blast away i don't care.

I will try to answer all of this:

My mileage calculations were from fillup to fillup. Maybe I am not filling it all the way sometimes and filling it all the way the next. I am a little concerned overflowing the fuel all over the fender. I am not familiar with diesel and feel like that large fuel hose may make a mess if I am not careful. I don not have any computerized anything on my beetle, just trip and odomoter.

Weight shouldn't be a problem. I am 185#. I drive in it by myself 3/4 of the time. The rest of the time I may have my two children (65# each) or my children and my 100# wife. There is nothing else in the car except the spare tire.

I don't have the wheel size with me, but they look stock. The wheel is a Michilin Hydoredge. After my first tank of 35mpg, I checked the air pressure and one tire was low. I fixed it.

The terrain is rolling hills to flat land. The drop/rise in elevation is nothing more than 200 ft. I am at 900ft elevation above sea level.

I don't know what a Vag-com is or a Block reading or a maf, sorry.

There are just over 61,000 miles on this beetle.


On a side note, I was watching the tachometer on the way to work today. It looks like it shifts between gears just before 2000 rpm and at a cruising speed of 71mph I am running around 2200-2300 rpm.

Honestly I don't know if my spedometer is working. I guess I will chedk that tonight. I could be going 80 instead of 70.

Thanks for the help.

Thanks for the help.

[h_2_o]

sorry let me re-ask the fuel question again i worded it poorly. when you go from fillup to fillup do you try and keep an constant 65 or whatever speed you are trying to stay at for that particular fillup or are you all over the place?

also try resetting your shifting logic in your transmission by doing the following and see if it helps any

Try the following procedure.

1. Turn the ignition ON, but don't start the engine.

2. Floor the gas pedal and hold it like that for 20-30 seconds.

3. Turn the ignition OFF, release the gas pedal.

this does not completely reset the dsg only the shift points back to stock. since it is an adaptive transmission and since you just got it, it learned to shift with the previous owners driving habits and not yours. I can not say this will gain much but it might gain some.

please post tire size for us as well please.

ignore the vag-com and maf questions for now. Later on if you want to dig deeper you might have to find a vw person in your area with a vag-com to help out. btw a vag-com is a piece of hardware and software the allows users to look closely at vw's hardware monitors through the car.

and one more question, is your check engine light on?

and yet another question, has the timing belt been done yet? if it was done and the person did not set the injection fuel pump timing correctly that could cause some problems. the initial after 03 i believe is 80k on that car but if someone did it sooner that could really throw a wrench into your mileage. BTW do not miss your timing belt changes

also one more note and this might not make you happy, but you are still within the vw norms of mileage, granted on the low end but still there. Hopefully something small is going on and you can resolve it.

edit again: change your fuel filter as previously mentioned, also check to make sure your lift pump is working, sit in the back seat and listen to it, have someone turn the key to the on position, you should hear a pump run for 2 seconds, then turn off. it will run while the car is running.

edit edit edit: also change your air filter and check the snow screen as well. use a good paper air filter not an oil based cleaner like k&n they tend to do bad things to the current mass air flow sensors in these cars.

[stinkbelly]

I tried to keep the speed the same between fillups. My normal speed is to set the cruise at 71mph.

I will get the tire size after work.

There is no check engine light on.

I have no idea about the timing belt, so I am going to assume it was not done. I thought about taking it to a vw dealer and seeing if he could tell me what has been done on it.

I know I am within the posted mileage, but I was hopeing for the upper end. It beats my previous daily driver at 12mpg.

[h_2_o]

sounds like you are doing the correct things. I doubt that the fuel filter has ever been changed and those are an every 20k thing. The first thing i personally would do is change the fuel filter and diesel purge it. I forget which type of fuel filter the 06's have if it is the mickey mouse clip one or the other, either way it needs to be done. The dieselpurge is just a good injector cleaning procedure that can have good affects. Besides that change out your air filter and clean the snowbox thing on the intake.

edit: here is a good video on changing out the fuel filter
http://www.cincitdi.com/videos/fuelfilter.html

here is an ok video on the dieselpurge
http://www.youtube.com/watch?v=-3zpwPNijnI

[stinkbelly]

My tire size is P205/55R16.

I checked the spedometer at 20, 30, 40, 50, 60, and 70mph. My speeds were 17, 28, 37, 48, 58, and 68mph respectively. So about 2mph lower than it actually shows. Now I checked the odometer against the mile markers on the road and it was right over 7 miles.

I am not sure what any of this means now.

I did change both air filters and clean out the boxes. I will do the fuel filter and purge.

[Kuplamies]

I have one tip for you, which has helped me every time, if I have had difficulties with low MPG:

I have noticed, that I must remember to "clean" my engine from time to time. The way I do it:

I drive approximately 30 kms (20 miles) with high rews!
Rews must be over 4000 rpm constantly. My car has 5 speed manual transmission, so I do that driving with 3rd or 4th gear. Motorway is the best place to do that.

I have done that cleaning process several times, and it has helped immediately. I am keeping a record of my gas fillings, so I know very well my Bugs behaviour and fuel consumption

My result so far:

* 90´000 kms (56´000 miles) with average of 5,1 liters/100 km (46 MPG).
* and latest tank was 4,95 liters per 100 km (47 MPG)

If I can´t get better result than 42 MPG per tank, I will do that cleaning! And it helps...!


Oh, needless to say that I am driving on the same roads daily, so it is easy for me to compare different tanks and get reliable results.