2009 Jetta TDI Fuel Economy

I just picked up my new 2009 Tdi and drove it 1000 miles (NC to Kansas). I must say, I was a little disappointed in the MPG - about 39. Avg speed 75 MPH. My '02 Tdi will do a very reliable 45. I am hoping that as the engine wears in the mileage will improve some.

It will.

NMRJock said:

I have also not seen much evidence to suggest that the manual gets 15-20% better fuel economy. I'm sure there's a small difference, but the numbers I'm seeing on the boards look very comparable.

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The European brochure shows 10% difference between the two.

2009 TDI just picked up 2 weeks ago - 800 miles thus far filled up once. 43 mpg mix of city/hwy. The onboard monitor actually is very accurate to the actual mileage I calculated.

Mpg Ok

I have an 09 TDI DSG and am on my 2nd full tank that I filled and my first tank I got about 32 MPG, this time I got 36 MPG. I'm pretty pleased but when I hear about getting 600 + miles on a tank I don't see it happening until maybe winter. DFW Texas area requires A/C running most of the time. When I fill up it only shows I have 515 to go until empty - that's the highest I have ever seen it. I got 476 on the last tank. Maybe people are driving until they are bone dry? I drive 37 miles each way to work but stop and go the last 15 miles probably.

mjsmonk said:

I have an 09 TDI DSG and am on my 2nd full tank that I filled and my first tank I got about 32 MPG, this time I got 36 MPG. I'm pretty pleased but when I hear about getting 600 + miles on a tank I don't see it happening until maybe winter. DFW Texas area requires A/C running most of the time. When I fill up it only shows I have 515 to go until empty - that's the highest I have ever seen it. I got 476 on the last tank. Maybe people are driving until they are bone dry? I drive 37 miles each way to work but stop and go the last 15 miles probably.

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That's interesting as the MFD on mine almost always show 600 miles when I first fill up... it must base that projection on your prior driving experience.

I could easily get 600 miles out of tank based on my driving habits - my worst tanks have been 42.5 (actual calculation) and my best tank was almost 46 mpg... I could easily get 48 if I were willing to slow down to 62 mph. You must have a LOT of stop and go, or be heavy on the throttle when excelerating to achieve mileage this low. I use a/c as well, and almost always use cruise on the highway.

Wes

15-20 % penalty is an average of all types of driving

On the 09 TDI-CR mpg threads there are quite a few DSGs , almost all are achieving mid to high 30s only on city loops & high 30s to very low 40s on mixed loops mpgUS .

While there are just as many 6 spd manuals returning from high 30s to mid 40s on city only loops & high 40s to around 50 mpgUS on mixed loops .

there are pages of people reporting that show this to be fact ,

So there is a 15-25+ % difference/penalty on city only loops with a 20+ % on mixed loops .

On Highway only loops there seems to be only a little difference/penalty , about 7-10 % .

But No one drives highway only so that works out to a ~15-20 % average penalty for the DSG over the 6 spd manual version in everyday real world driving .

Something else that people have been reporting is quite a bit better mpgs on manuals especially when driven very hard compared to when DSGs are driven hard . As much as a 30 % penalty has been reported on this one .

rotarykid said:

On the 09 TDI-CR mpg threads there are quite a few DSGs , almost all are achieving mid to high 30s only on city loops & high 30s to very low 40s on mixed loops mpgUS .

While there are just as many 6 spd manuals returning from high 30s to mid 40s on city only loops & high 40s to around 50 mpgUS on mixed loops .

there are pages of people reporting that show this to be fact ,

So there is a 15-25+ % difference/penalty on city only loops with a 20+ % on mixed loops .

On Highway only loops there seems to be only a little difference/penalty , about 7-10 % .

But No one drives highway only so that works out to a ~15-20 % average penalty for the DSG over the 6 spd manual version in everyday real world driving .

Something else that people have been reporting is quite a bit better mpgs on manuals especially when driven very hard compared to when DSGs are driven hard . As much as a 30 % penalty has been reported on this one .

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I challenge you to find posts regarding 2009 TDI'S that show this disparity between sticks and manuals. Honestly I think I've personally reported some of the highest mileage numbers so far for the 09 model, and I'm driving a DSG with around 6K on the clock. My worst tank has been 42.5 and my best around 46. I erroneously mistyped 48 in a post several weeks ago. I could definitely achieve 48 if I were willing to slow to 62 mph... but so far haven't been able to consistently do that for a tank of fuel. I would expect, based on all that I've read, for the dsg/manual penalty to be around 1 mpg, as is also reported in several articles I've read. Actually the a/c seems to whack 3-4 mpg... much more than the DSG, and this seems especially true on the highway. Based on 45 mpg, a 3% variance would be 1.35 mpg, and I think that's MUCH more realistic than the 15-20% you're suggesting.

If you can find ANY posts that indicate a "FULL TANK actual calcuation" for an 09 TDI stick that demonstrates mpg of anything above 45, then I'll stand corrected. Otherwise, I speculate you may be confusing posts of earlier model years.

Wes

I would be happy to get in the 40's. I've been driving my car easy and it will NOT manage 40 MPG on interstate. Sure display will occasionally show 40's but on tank full from exit to exit it will only squeeze out 34-38. And that's only driving 75 MPH or less turning A/C on and off. I've noticed I've actually started driving slower trying to make this car get the mileage claimed. I drive about 2000 miles a month all interstate and slowing down to 70 MPH is adding time to my trips. I seriously doubt people are getting in the mid 40's on the interstate. I can drive on back roads at 60 MPH and get mileage claimed. Unfortunately that's not why I bought the car. This car is taking all the fun out of my drives.

Is it an auto or stick?

GotTDI? said:

I would be happy to get in the 40's. I've been driving my car easy and it will NOT manage 40 MPG on interstate. Sure display will occasionally show 40's but on tank full from exit to exit it will only squeeze out 34-38. And that's only driving 75 MPH or less turning A/C on and off. I've noticed I've actually started driving slower trying to make this car get the mileage claimed. I drive about 2000 miles a month all interstate and slowing down to 70 MPH is adding time to my trips. I seriously doubt people are getting in the mid 40's on the interstate. I can drive on back roads at 60 MPH and get mileage claimed. Unfortunately that's not why I bought the car. This car is taking all the fun out of my drives.

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Tran type...

I'm WNY PAT said:

Is it an auto or stick?

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GotTDI: 09 TDI automatic with 725 miles. Fuel mileage at this point very disappointing. I have tested all city and all highway. My fillups are exit to exit on intersate and are completely filling tank. In town I'm getting 34 MPG. Problem is on highway mileage is very poor. Got only 35 MPG at 75 MPH with AC on. Driving same trip slowing down to 70 MPH without AC still only managed 38.5 MPG. These were 210 mile round trips. Computer seems to be showing pretty close to actual. I hope this gets MUCH better or I'll be looking for used 06.

I seem to remember a couple of months ago just before this model was released how everyone seemed to be swearing how much better the fuel economy was going to be compared to the 1.9 PD or better than the Euro 2.0L 140 HP 2009 model. Looks like reality is starting to kick in at last.

GotTDI? said:

I would be happy to get in the 40's. I've been driving my car easy and it will NOT manage 40 MPG on interstate. Sure display will occasionally show 40's but on tank full from exit to exit it will only squeeze out 34-38. And that's only driving 75 MPH or less turning A/C on and off. I've noticed I've actually started driving slower trying to make this car get the mileage claimed. I drive about 2000 miles a month all interstate and slowing down to 70 MPH is adding time to my trips. I seriously doubt people are getting in the mid 40's on the interstate. I can drive on back roads at 60 MPH and get mileage claimed. Unfortunately that's not why I bought the car. This car is taking all the fun out of my drives.

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Give this a try and see if it doesn't make a difference. My WORST tank experience was 42.5mpg. This was in the mountains of WV with the a/c on all the time, averaging 70-75 mph... USE YOUR CRUISE. Here's what I think you're doing. All of us that are used to driving gassers tend to apply WAY more pressure to the accelerator than necessary when going up a hill. If you'll watch your MFD continous readout, you'll notice that you're dropping your mpg WAY BACK when going up a hill, and at the same time, I bet you'll find that you're actually GAINING speed when going up an incline. This means you're using MORE fuel than necessary to maintain your speed.

USE YOUR CRUISE... just try it for a couple hundred miles when you're on the interstate. I almost guarantee you your mileage will jump significantly. Honestly, I would have to make a real effort to get mileage as poor as you're reporting!!!

The other issue is obviously speed. I find the mpg difference between 65 mph and 75 mph is HUGE, and that is especially true in hilly terrain. If you plan to drive this car at 75 or greater, you will NOT get mileage in the high 40's... too much wind resistance, just ain't gonna happen. At the same time, if you were able to drive at 60 mph, you could hit 48-50 mpg without a problem, and even more if you're traveling flat terrain. Keep in mind the couple doing the cross country at present is driving the SAME car we are with NO modifications, and they're seeing high 50's... but they're NOT driving fast.

There is currently NO car in the US that can travel at 75 mph or greater and accomplish mileage in the high 40's... just simply doesn't exist IMHO.

My 09 tdi is a DSG and has a little over 6K on the clock.

Wes

I just filled up at 504 miles I think.

09 Jetta TDI DSG, 16" wheels, sunroof.
35.9 MPG according to the car, 35.8mpg according to my calculator and the fuel receipt.

Unlike a lot of you guys I'm really happy with that number. Unless I'm missing something, I'm getting on the high end of the 29/40 rating with a mostly interstate commute and the A/C on most of the time. Plus I've been reading a lot that you don't see real gains until a couple thousand miles down the road.

I'd be hard pressed to find a gasser that compares when you take into account torque, fun factor, design, fuel economy, etc. This car is badass.

PS. Stop driving it easy all the time, have a little fun with it!

Actually I feel I drive mine hard some of the time, yet I'm still getting 42.5 to 46 on a tank - but admittedly, it's mostly highway, probably 90%.

Wes

Why are you concerned about MPGs now?

Shouldn't you be driving the '09s hard during at least the 1st OCI to properly seat the rings and all?

From what I have read, it is more important to properly break-in the new TDIs than worry about economy now.... after 10k on the odometer, that is the time to be more gentle and try for economy...

that is my opinion...

wesk1954 said:

Give this a try and see if it doesn't make a difference. My WORST tank experience was 42.5mpg. This was in the mountains of WV with the a/c on all the time, averaging 70-75 mph... USE YOUR CRUISE.
Wes

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You shouldn't be using your cruise. No steady state driving. You should be cycling through firm accelerations with load (i.e. not first gear accelerations) followed by engine braking every time you drive. Check out Drivbiwire's break-in regimen under the TDI 101 How-Tos thread.

Worry about fuel economy after you've broken in the engine.

jvance said:

You shouldn't be using your cruise. No steady state driving. You should be cycling through firm accelerations with load (i.e. not first gear accelerations) followed by engine braking every time you drive. Check out Drivbiwire's break-in regimen under the TDI 101 How-Tos thread.

Worry about fuel economy after you've broken in the engine.

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There are no issues using cruise when going up mountains. Gravity provides the variable load. From 2 to 15 lbs of boost depending on slope.

Alot of the mpg numbers here are skewed by newbies who don't know that you must drive differently/slower, listing partial tanks, don't fill properly, 1st tank wasn't filled and others. I was there myself when I got my 06. There isn't any other car out there that will do what this one can economy wise no matter what speed you go. Unless people start reporting full tank averages with the conditions driven over multiple tanks, all the newbies will be confused. A 50 mile drive crawling along at 40 mph and getting 102 mpg and reporting here does nothing but confuse people. Please report only full tank averages and things will look much clearer. Read this thread on 800 mpt drivers in 2006's to see what needs to be done. Some of them have multiple tamks over 800 miles and have learned something.

http://forums.tdiclub.com/showthread.php?t=134203

wesk1954 said:

There is currently NO car in the US that can travel at 75 mph or greater and accomplish mileage in the high 40's... just simply doesn't exist IMHO.

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I agree with most of your post. Again, I think the DSG penalty is quite small. We're getting low 40's MPG for our 09 with DSG. But you should have said that "There is currently NO car in production in the US that can travel at 75 MPH or greater and accomplish mileage in the high 40's."

Because our '00 Jetta will do 75 MPH (actual, by GPS) and return high 40's to low 50's MPG all day long.

Honestly guys, if you want maximum fuel economy buy a MkiV TDI. I've had an '01 Jetta and now I have a '00 and they get ~50 MPG real-world driving (no hypermiling) on my daily commute.

Now, if you want really good fuel economy and also want good performance and a lot more comfort, then the MkV is a great choice.

That's why we have one of each. I get fantastic fuel economy and less comfort on my daily commute. My wife gets really good economy and is much more comfortable on her commute. We'll take the '09 on most trips, because I'm willing to trade some economy for some comfort.

That's also why we g0t DSG. I'd have preferred a manual transmission but my wife really wanted DSG. It makes her happy, and it only cost us ~$1100 more (Plus a couple hundred every 40k miles). It is probably costing us one or two MPG overall, but it's worth that if it makes my wife happy.

FWIW, our numbers (from my wife's daily commute. No hypermiling) look just like the average numbers I'm seeing people report for manual transmission '09s. As a matter of fact, I told her to drive it hard to break it in. I know she's not babying it.

time to dust off an oldie but a goody...

this guy boasts a lifetime avg of nearly 60 mpg in a VE engine. maybe he has a few tricks that will work for the new engine?

http://forums.tdiclub.com/showthread.php?t=123503

I don't know what the drag coefficient is for the JSW, but suffice to say, at 75MPH the penalty is indeed big. Many forget, or don't know, wind resistence goes up exponentially with speed (..the square of the velocity). With a steep windshield, 205's, etc., I can't imagine great mpgs should be expected?

I will be hypermiling the DSG over columbus weekend and we'll see what a it can do over rolling highway using neutral. I will be the guinea pig on this tranny. You pretty much only have to mate revs for 6th when going back into 'D'. That way shifts are merely seen, never felt . I've broken 50mpg, but so far only on meaningless MFD short trips.

MrSprdSheet said:

I don't know what the drag coefficient is for the JSW, but suffice to say, at 75MPH the penalty is indeed big. Many forget, or don't know, wind resistence goes up exponentially with speed (..the square of the velocity). With a steep windshield, 205's, etc., I can't imagine great mpgs should be expected?

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EXCELLENT point. I would be thrilled to get in the mid-high 30 mpg range while driving at 75 mph. For reference, the aero drag goes like this with speed (reference 50 mph):

55 mph: 1.21 more drag than 50 mph
60 mph: 1.44 "
65 mph: 1.69 "
70 mph: 1.96 "
75 mph: 2.25 more drag than 50 mph

Lightflyer1 said:

Alot of the mpg numbers here are skewed by newbies who don't know that you must drive differently/slower, listing partial tanks, don't fill properly, 1st tank wasn't filled and others. I was there myself when I got my 06. There isn't any other car out there that will do what this one can economy wise no matter what speed you go. Unless people start reporting full tank averages with the conditions driven over multiple tanks, all the newbies will be confused. A 50 mile drive crawling along at 40 mph and getting 102 mpg and reporting here does nothing but confuse people. Please report only full tank averages and things will look much clearer. Read this thread on 800 mpt drivers in 2006's to see what needs to be done. Some of them have multiple tamks over 800 miles and have learned something.

http://forums.tdiclub.com/showthread.php?t=134203

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I completely agree with you. Having over 6K on my 09 already, all my posted tank averages were just that, FULL TANKS driven 4-600 miles before fill up, and using actual calculations. Many are reporting the MFD as accurate, I'm personally finding a variance of .5 to 1.5 mpg, and it's always optimistic in my experience.

I don't think "running the crap" out of a new diesel is "required"... rather driving a highway speeds where there's plenty of variation and LOAD... particularly what I naturally find in mountainous terrain. Screaming off from dead stops is NOT the viable solution for breaking in the engine, rather, varying the rpm's UNDER LOAD, particularly increased load such as an incline with heavy acceleration really helps seat the rings in my opinion.

I know the car if fun - I'm loving mine, but driving it "shot rod" at high rpm's is NOT the best way to break it in. This engine will be just fine if driven as you normally would, assuming you have highway miles involved in your travel and are placing the engine under load and increased rpm's.

Having a new TDI is a great excuse to drive it like you stole it, but you aren't necessarily doing it a favor by doing so. Increased pressures on all the drivetrain when performing these antics from a dead stop. Fun? Yes! Helpful? I don't think so.

DRIVE IT... put some miles on it, and even doing so, if you drive "well"... you'll still see great mileage numbers like I've experienced thus far - worst tank at 42.5 (that was mid 70'smph in WV mountains with a/c) and a high tank of 46 (mostly flat terrain in Ohio).

Wes

MrSprdSheet said:

I don't know what the drag coefficient is for the JSW, but suffice to say, at 75MPH the penalty is indeed big. Many forget, or don't know, wind resistence goes up exponentially with speed (..the square of the velocity). With a steep windshield, 205's, etc., I can't imagine great mpgs should be expected?

I will be hypermiling the DSG over columbus weekend and we'll see what a it can do over rolling highway using neutral. I will be the guinea pig on this tranny. You pretty much only have to mate revs for 6th when going back into 'D'. That way shifts are merely seen, never felt . I've broken 50mpg, but so far only on meaningless MFD short trips.

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I live in OHio as well, and we're blessed with flat terrain in many areas. I find I can achieve 48 mpg (in the flatter parts of OHio) at 62 mph, and that's without a/c. I would guess, but haven't had the patience to try it, that I could easily break 50 mpg if I would drop my speed to 58-60.

I would love to know what the average speed per tank has been for the couple that's crossing the US at present and getting nearly 60 mpg on the new Jetta. I bet their overall average would be in the high 40's. Perhaps they'll post those numbers in the future

I wanted to have a 48mpg average on my last tank of fuel and was doing well - until last Saturday when I was delayed by road construction and had NO choice but to increase my speed to 70 mph for around 100 miles... that blew it for that tank. In fact I ended up with 42.5 which is a match for "worst tank" so far.

I've shifted into neutral on some LONG declines in WV mountains, and shifting back into drive doesn't seem to be an issue at all... it's very smooth and without incident. I too share a mild concern in doing this, but it doesn't seem to be a problem.
Wes

dr61 said:

EXCELLENT point. I would be thrilled to get in the mid-high 30 mpg range while driving at 75 mph. For reference, the aero drag goes like this with speed (reference 50 mph):

55 mph: 1.21 more drag than 50 mph
60 mph: 1.44 "
65 mph: 1.69 "
70 mph: 1.96 "
75 mph: 2.25 more drag than 50 mph

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EXCELLENT info... where did you find this? Is this pertaining to the Jetta in particular?

Wes

wesk1954 said:

EXCELLENT info... where did you find this? Is this pertaining to the Jetta in particular?

Wes

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It's simple physics. The force increases by the square of the velocity (times a bunch of constants like the drag coefficient, density of the air, frontal area, etc).

So, say the drag at 50 mph is 1.0. The drag at 60 is 1.0*(60/50)^2 or 1.44.

That's 44% more aerodynamic drag at 60 mph than at 50 mph. That's a great illustration of why speed is by far the largest factor for highway fuel economy.

wesk1954 said:

EXCELLENT info... where did you find this? Is this pertaining to the Jetta in particular?

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He's calculating (V/V_0)^2. See http://en.wikipedia.org/wiki/Drag_(physics) for further discussion.

Note that in the above article it discusses the fact that the power required to move an object through a fluid (air is a fluid, but it's compressible, which makes these approximations slightly inaccurate) at a particular speed is related to v^3, since power = force x velocity. However, the total energy expenditure is the integral of the power over time; if you travel twice as fast, you must use 8x as much power, but for only half as long, so the total energy expended is 4x as much, i.e., proportional to v^2.

Picked up my 09 Jetta TDI last friday in Lancaster, PA. currently on my 2,500 mile vacation/journey home. (Zig Zag Route to North Dakota). I am extremly pleased with this new car. First tank with 20% city hand calculated 41.96mpg. Great power, and handling. The MFD is real close. Love the car. Will report back later.

pawel said:

There are few TDI drivers that said that they are frustrated with low numbers... I guess they are not reading to what more experienced TDI owners are saying... give it some time, break in the engine and then start comparing your mpg's...

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Unfortunately many new TDI owners are comparing their fuel mileage with the results reported by a tiny minority of outliers.

Most drivers of the VE TDIs (2003 and earlier) reported less than 45 mpg. (those with ATs less than 40 mpg) My '03 Golf's lifetime average is about 40.5 mpg -- but when it was new, I was seeing 35-37 mpg for the first 3000 miles.

Most drivers of the PD TDIs (2004-2006) reported less than 43 mpg. And among those who just drive, and don't try to save fuel, the average is probably in the high 30s.

Yes, many TDI Club members report fuel mileage in the high 40 mpg range or even higher. These are not typical numbers -- to get that kind of mileage, you have to drive a certain way on a certain kind of highway, and maybe at the right time of year. They may have created an unrealistic perception, that 50 mpg is possible and 45 mpg is easy, regardless of where you drive.

Of course, the VW bigwigs helped to create this perception too, when they dropped "60 mpg" into their comments last winter and spring.

It really is too early to draw any conclusions about fuel economy with the 2009 CR TDI engines -- we should wait until there is a large sample with more than 10k miles.