'13 TDI Wagon - Poor MPG - 10 mpg less than avg

I am new to this group and signed on to get some TDI advice. My wife and I purchased a 2013 VW Jetta SportWagon TDI this past fall. We were told that the avg MPG should be around 42mpg and once the engine breaks in it should be closer to 50.
We have 15k miles on the car and are averaging 32mpg with our last 2 tanks being 29 and 31 mpg. The highest mpg we ever got on a tank was 36 mpg and that was when we drove straight highway, mostly on cruise control, on our way to the coast and back.
I took the car in for testing this am and the dealership called and said they can't find anything wrong with the car. I will get a further explanation when i pick up the car and will post it then. This is a substantial decrease in lost mpg and negates the reason for turning in our 2011 Nissan.
Does anyone have any idea what is causing this or what I can do? We drive 80-90 percent highway miles with no traffic as my wife is a nurse that works 11-11 where there is no highway traffic.
Thank you in advance.

How quickly do you drive? Being in Texas with higher speed limits, your fuel economy will be lower than people in other areas who travel at slower speeds.

How much do you use the brakes? Be sure to look ahead and brake a little as possible for the best fuel economy possible. I've seen people going down the highway accelerating rapidly to catch up to traffic, then jamming on the brakes to slow down, then accelerating again, over and over. I'm not saying that you're one of these people, but that type of driving is certainly not conducive to good fuel efficiency.

Welcome to the forums!

Standard driving and breaks. Lets put it this way, we have both had many vehicles and have always maximized the mpg so I don't think driving style has anything to do with this. I have a pickup and I get get better than avg mpg on that.

Another thing to look for would be a dragging brake caliper. Go for a drive down the road for a little bit, then get out and check the wheels to see if one in particular is hotter than the others.

Thanks veedub. I guess we do drive a bit faster. Usually 70-75 avg w the limit being 70 in most places. We do not accelerate to take off or slam breaks. Would driving at a higher speed take mph down to 32? I can't imagine it would be that much of a decrease. Again, the best I've ever seen was 36. I am heading to the dealer now and will let you know exactly what they say.

Is it 6MT or DSG ? Also, A/C on or A/C off ?

36mpg @ 70-75mph w/DSG and A/C sounds about right.

You don't say, but I'm guessing this is a DSG. If your wife's driving is primarly suburban or in traffic and she isn't using any mileage improving driving techniques, your number isn't far off, and you're between the EPA city and highway numbers, which VW is going to tell you is what the car should be delivering. You're in a hot climate which probably means extensive A/C use. This, along with shorter low speed trips (lots of Regens) will drive FE down. If you have larger than the stock 16" wheels that doesn't help either. Folks up here are seeing FE in the high 20s and low 30s driving in the city in winter.

Even 36 with A/C on at 75 MPH isn't terrible, although it's certainly not excellent. If the dealer employee either had been honest or had a clue perhaps you'd be less concerned.

I think the dealer was selling you a load. Those new cars don't get 50mpg without modifications and effort. If you look at Fuelly profiles for the new TDIs, the average is nowhere near 50... usually in the mid-30s. They were either lying or sadly misinformed, and sold you a car based on that.

There's a guy here that's getting 800 mile tanks in his MKVI Golf, averaging FE somewhere in the mid-50s. But who knows where and how he's driving to achieve that. I get mid-40s in my Golf, but it's a two door manual. the lightest MKVI out there, and I drive mostly highway. And I have 15" wheels on it. Sportwagens are getting mid 30s much of the time, especially DSGs.

I think someone inflated your expectations by telling you that it would get 50 MPG with ease... that's a tall order in a DSG Sportwagen even in ideal conditions.

Drive with the 'instantaneous mpg' function on for a while and see if you can increase your fuel economy. The engineers put it there for a reason. I found it very helpful when I first bought my car. IMHO, you should be averaging better than 36 mpg if you drive the way you say you do. The dragging brake caliper has been a problem for some. You can get 50 mpg under good conditions but you have to slow down to between 60 and 65 mph (or have a strong tail wind). Good luck.

The vehicle is EST and is driven mostly highway. Not short trips. Ride to work is 24 miles each way. AC is on. We got 36mpg one time, tjis is not avg, and that was on a long trip to the coast using cruise control the entire time. Avg mpg is about 32. Last two tanks were 29 and 31.

Here is what the VW dealer said...

Operating to spec. Avg gas consumption according to MFI is high @35.6mpg and low at 21.3 mpg. Perform fuel consumption test through MVB 15. Took 3 avg cruising at 60mph. Spec is 3.8 L/hr. low at 1.83l/hr high at 3.99 L/hr. operating to spec.

Can anyone decipher this? All they would tell me is that it's normal. The high mpg at 35.6 seems very off to me. Thanks in advance.

http://www.fuelly.com/car/volkswagen/jetta/diesel l4/wagon

The average for a 2013 Sportwagen TDI on Fuelly is 38.1 MPG reported by 145 cars.

The average for a 2012 Sportwagen TDI on Fuelly is 36.6 MPG reported by 235 cars.

TDI in ATX said:

Here is what the VW dealer said...

Operating to spec. Avg gas consumption according to MFI is high @35.6mpg and low at 21.3 mpg. Perform fuel consumption test through MVB 15. Took 3 avg cruising at 60mph. Spec is 3.8 L/hr. low at 1.83l/hr high at 3.99 L/hr. operating to spec.

Can anyone decipher this? All they would tell me is that it's normal. The high mpg at 35.6 seems very off to me. Thanks in advance.

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Like IBW said in his 1st post, your fuel economy numbers are within the normal EPA estimate range. You are far from the first person to be stuck in the mid 30's for fuel economy, especially with a DSG wagon. Consistent 45+mpg out of stock '09+ cars isn't the norm.

Your car also is not yet broken in. And my cars get better FE when I don't use cruise.

I have to work really hard to average 41-42. I'd say the dealer lied to you when you bought it. 50 is very very hard to do in a CR with the DSG.

WutGas? said:

I have to work really hard to average 41-42. I'd say the dealer lied to you when you bought it. 50 is very very hard to do in a CR with the DSG.

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Not hard in a Passat!

Sorry, couldn't resist.

My average is just over 40mpg at almost 10k miles. However I drive a lot of highway (trips of at least 75-100 miles each way). I would check tire pressures as well. I run at least 38 psi in mine vs the 30-32 average the dealer puts in. I have found that ac use and speed hold the most influence on mpg.

One thing I may have forgotten to mention is that the car has 15,000 miles on it. I gave it plenty of time to break in. I was hoping to see an increase at this point. I will try the higher PSI.

I am driving from Austin to New Orleans tonight and I am going to try and get the best possible mpg as I can since it is 500 miles straight highway at night. Suggestions on maximizing this fuel efficiency?

First, 15K is getting broken in, but isn't fully broken in. Believe it or not, it takes about 60K. For tonight's trip, check tire pressures, go to maybe 44 if they're warm, don't use cruise. I know others here would tell you to go 60 or 65 MPH but that would make me crazy. I'd keep it under 75. Fill it until you see clear fuel in the filler neck, do it again when you get there to get a reliable MPG reading. Some fuel additive like Power Service with cetane boost (gray bottle) wouldn't hurt. I find all my TDIs to be fairly fuel sensitive.

So are any of the brakes dragging a bit? As posted a few up, a dragging caliper will eat mpgs and make the wheel hotter than the rest over a highway drive.

TDI in ATX said:

The vehicle is EST and is driven mostly highway. Not short trips. Ride to work is 24 miles each way. AC is on. We got 36mpg one time, tjis is not avg, and that was on a long trip to the coast using cruise control the entire time. Avg mpg is about 32. Last two tanks were 29 and 31.

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I've got a 2012 JSW with DSG. From experience, I have to work hard (i.e. "safe" hypermiling) to get 40 mpg. If I just drove the car "normally" (like when my wife gets behind the wheel), that number would easily drop to 32. I'm even using cruise control at most times in the city, and moderating speed with the rocker switch, coasting in neutral to stops, gliding as much as possible, tires at 40 psi...Did I mention I'm working really hard at maximizing mpg?

I bought the car in the US and drove it back to Canada, so I had two solid days of highway driving. If you check my fuelly - I had a couple of tanks that were 31 mpg. I was driving 70-80 MPH, headwinds/sidewinds, A/C at times. Yep...31 mpg. Same as you. There probably isn't anything wrong with your car, you're just not driving it in the controlled EPA conditions that has it at 29 city / 39 highway.

I've accepted that my JSW is very different than a 2-door golf, and not to expect an 800 mile (56 mpg) tank anytime soon.

TDI in ATX said:

One thing I may have forgotten to mention is that the car has 15,000 miles on it. I gave it plenty of time to break in. I was hoping to see an increase at this point. I will try the higher PSI.

I am driving from Austin to New Orleans tonight and I am going to try and get the best possible mpg as I can since it is 500 miles straight highway at night. Suggestions on maximizing this fuel efficiency?

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How did this go? In the meantime, my belated suggestions:

1. Tire pressure = 40PSI
2. Turn computer display to instantaneous fuel consumption readout
3. Turn off cruise, or at least go for period without cruise
4. Try to keep the MPG readout as high as possible
5. Hold speed to 70MPH
6. Turn off AC for periods of time if possible (since you are travelling at night)
7. Leave enough distance between you and other vehicles so you never touch the brakes.

Don't leave the A/C temp at 60* and re circulated the air in the cabin. Bike racks kill MPG

VeeDubTDI said:

I think someone inflated your expectations by telling you that it would get 50 MPG with ease... that's a tall order in a DSG Sportwagen even in ideal conditions.

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This!

Check fully, you will see very few of these cars AVERAGING 50 MPG!

bvencil said:

How did this go? In the meantime, my belated suggestions:

1. Tire pressure = 40PSI
2. Turn computer display to instantaneous fuel consumption readout
3. Turn off cruise, or at least go for period without cruise
4. Try to keep the MPG readout as high as possible
5. Hold speed to 70MPH
6. Turn off AC for periods of time if possible (since you are travelling at night)
7. Leave enough distance between you and other vehicles so you never touch the brakes.

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7a. Learn the nuances of coasting / coasting in gear (which uses zero fuel).

Some people avoid cruise, others (like me) use it all the time, even in the city - which is where I do most of my driving. Just keep in mind that if you're going uphill, cruise will accelerate to maintain a constant speed (which kills mpg). Before hills, I accelerate to the hill and decelerate going up - usually by pressing down on the rocker switch. Accelerate while going down hills to "bank" your momentum for the next hill. I tend to drive my car as if I was riding a bicycle, using the least amount of effort possible to preserve momentum.

psd1 said:

This!
Check fully, you will see very few of these cars AVERAGING 50 MPG!

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Great point! I'd also add that the people that that track FE on Fuelly work hard at maximizing mpg. For that reason, Fuelly results are skewed to the high side.

How long (time and miles) is your typical trip? The TDI tends to take a few miles of warming up before getting optimal fuel economy. I often see my average fuel consumption 1 estimate start in the single digits and increase throughout my 25-28 mile commute.

Cruise control at 70-75mph should net you at least 40mpg except for into a headwind. Maybe your car has an alignment issue.

How are you measuring your FE? Do you use Fuelly or some other way to log miles driven and fuel consumed?

Great point! I'd also add that the people that that track FE on Fuelly work hard at maximizing mpg. For that reason, Fuelly results are skewed to the high side.

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Not me! I drive aggressively because 10% extra fuel for any given vehicle is so worth the driving experience.

The dealer lied to you. www.fueleconomy.gov site lists the specs at 29 city 39 highway, which is what you are getting. The cars seem to like long trips (longer the better) and steady state cruising. My commutes in the new Passat are as follows:

5 mile commute 32mpg Cat Hollow to Parmer and McNeil
35 mile commute 44 mpg Round Rock to Oak Hill Non rush hour on 183/MoPac
400 mile RT to Dallas at 65 mph 51.4 mpg

Expect the numbers from the site above if you do any of the following:
1 Drive at/over 70 mph
2. Drive short trips
3. Drive in traffic congestion

My short trips commuting kill my economy numbers, but I use less fuel. In a few months my company is moving us to Oak Hill and my commute will change to 35 miles one way. The economy numbers will go up but I will burn more fuel. I have the advantage of swinging my start/quitting times though, so I can avoid most if not all of rush hour(s). I am in Round Rock and have VCDS if you ever find the need as well. PM me if you would like to talk or meet up sometime!