12 A3 TDI vs 12 Jetta TDI MPG

rotts4u

Veteran Member
Joined
Aug 21, 2011
Location
California
TDI
None
About 9 months ago I bought a 2012 JEtta sedan for myself and thus far over the 15500 miles I have averaged 40.5mpg hand calculated on fuelly. I liked it so much I talked my wife into getting rid of her BMW 135i vert and into an A3 TDI which she really like too.

Thus far I only have about 1600 miles on the A3 and the mileage on it is nowhere near the Jetta. I don't think she is as obsessed with mileage as I am so her driving habits may be slightly worse than mine but she also drives slightly more highway miles to and from work than I do. Thus far on three tanks she is averaging 34.5mpg. This weekend I even drove it on the interstate for about 200 miles and went sub 70mph and didn't get the normal 48-50mph (display) that I get on my Jetta when I do the same with no Ac running.

Both cars are DSG autos but they do have different tires with the Jetta running on bridgestones and the Audi on continentals. They may be different sizes too s I need to check that.

I know the engines are slightly different but I noted that on fuelly the A3 TDI just does not produce the same MPG as the Jetta TDi. Any ideas why anyone?

Not that I am complaining over 34.5 mph compared to the 20 mpg on the premium gas burning BMW but I expected more like 38ish.
 

skramer

Veteran Member
Joined
Apr 24, 2012
Location
Viera, FL
TDI
2015 GSW SE 6MT
About 9 months ago I bought a 2012 JEtta sedan for myself and thus far over the 15500 miles I have averaged 40.5mpg hand calculated on fuelly. I liked it so much I talked my wife into getting rid of her BMW 135i vert and into an A3 TDI which she really like too.

Thus far I only have about 1600 miles on the A3 and the mileage on it is nowhere near the Jetta. I don't think she is as obsessed with mileage as I am so her driving habits may be slightly worse than mine but she also drives slightly more highway miles to and from work than I do. Thus far on three tanks she is averaging 34.5mpg. This weekend I even drove it on the interstate for about 200 miles and went sub 70mph and didn't get the normal 48-50mph (display) that I get on my Jetta when I do the same with no Ac running.

Both cars are DSG autos but they do have different tires with the Jetta running on bridgestones and the Audi on continentals. They may be different sizes too s I need to check that.

I know the engines are slightly different but I noted that on fuelly the A3 TDI just does not produce the same MPG as the Jetta TDi. Any ideas why anyone?

Not that I am complaining over 34.5 mph compared to the 20 mpg on the premium gas burning BMW but I expected more like 38ish.
Not sure....Just picked a new to me 2012 A3 TDI

On the 300 mile trip back from the dealer...averaged 43.8mpg (using Dinfo display) as I have not completed a tank yet to figure out fuelly. Speeds 70-80mph. My audi has 7200 miles on it, yours still could be in break-in period with only 1600
 

ReadyKilowatt

Active member
Joined
Apr 15, 2012
Location
Aspen, CO
TDI
2012 A3
After just over 900 miles, I've filled up once and topped off (1/2 tank) once.

According to Fuel Log (android app) the first tank got me 39.51MPG and the 2nd 39.2MPG. This is driving in Colorado, above 5500 ft, mostly highway. No cruise control and a mix of "manual" and automatic drive.

I'm still on the break-in regimen so there's no shifting above 2500RPM until I get over 1K miles (hopefully today or tomorrow!), no cruise and varying the engine speed every few miles or so on the highway. The trip computer usually has me averaging above 40MPG, but I haven't been paying attention to fuel economy right now due to break-in driving. I expect it to get worse for the next 1000 miles, when I can begin to wind out the engine.
 

Vin63

Veteran Member
Joined
May 20, 2011
Location
SoCal
TDI
Audi A3
Not sure if this helps, but my wife and I have actually done comparative mileage drives. Generally, she averages 5-7 mpg less than I do driving the same course (we drive from LA area to SF Bay Area to visit family several times a year - about 800 mile round trip). Personally, I think it is because she is not as smooth on the throttle, and does a lot of nervous type of on-off the throttle movements. She also will stay on the throttle to a stop or red light and immediately brake instead of coasting - I think part of that erratic throttle habit - she's just more of a nervous driver than I am.
 

jgeorge

Veteran Member
Joined
Aug 11, 2011
Location
aurora, ontario, canada
TDI
2010 audi a3 tdi
Your jetta is way ahead in breakin, check the footprint of the tires on both cars- our 2010 A3 is 225/45-17. Not sure if the jetta is as wide- Wider tires create more resistance. Compare tire pressures. Compare vehicle curb weights. You could try driving side by side on the freeway when traffic is light, starting and finishing between 2 landmarks on level ground. Even 2 sign posts. Not tandem as the chase car will have an advantage of drafting. Do this for a few hundred yards using instant consumption display.Write down your observations. Make sure both cars are using the same brand of fuel for several tanks from the same station and roughly the same amount in each tank before you try this. It would be interesting to see the results.
 

rotts4u

Veteran Member
Joined
Aug 21, 2011
Location
California
TDI
None
I checked and both cars have 225/45/17 tires and I run the same (high) pressure in both cars. Since I track fuel mileage in fuelly on both cars and have since new I went back and looked at the Jetta when new and though it was slightly lower than now, by 2-3 tanks it was up to 38.9mpg and rising. The third month it was up to 40.6 mpg which is about exactly the same as now 9 months later.
 

skramer

Veteran Member
Joined
Apr 24, 2012
Location
Viera, FL
TDI
2015 GSW SE 6MT
I checked and both cars have 225/45/17 tires and I run the same (high) pressure in both cars. Since I track fuel mileage in fuelly on both cars and have since new I went back and looked at the Jetta when new and though it was slightly lower than now, by 2-3 tanks it was up to 38.9mpg and rising. The third month it was up to 40.6 mpg which is about exactly the same as now 9 months later.
Your also forgetting the weight difference between the cars, I do believe the A3 is a heavier car, even w/o having quattro...

Then coefficient of drag probably is different, as well as frontal area
 
Last edited:

chetdi

Active member
Joined
Oct 13, 2011
Location
San Francisco Bay Area
TDI
2012 A3, 2011 JSW
FWIW, I have a '12 A3 TDI I bought in October, and my wife has a '11 JSW TDI she bought in July. At this point we both have about 16k miles on them (I caught up!).

On paper (I keep a spreadsheet with fillups.. no Fuelly yet), I average about 37mpg in the A3, and she averages about 36mpg in the JSW.

My commute consists of about 45 miles of highway and 5 miles of city each way, and her commute consists of about 10 miles city and 20 highway. I drive 80-90 if I can help it, and she drives 80 if she can help it.

In my experiences with driving around 60-70mph, I definitely have yielded 43-45mpg on paper (51mpg per the trip computer). My wife doesn't really track that stuff on her JSW, but I'm guessing it's similar.

So yeah, if she's hovering around 34.5mpg, my thoughts would be driving a little heavier, running the AC a lot, or maybe she occasionally drives around a trailer full of horses? :)
 

sledstorm1

Veteran Member
Joined
May 16, 2009
Location
Austin MN
TDI
2011 Golf Tdi 4dr 6mt
Are the dsg's geared the same? Maybe the A3 is geared more for sport rather than fuel economy.
 

Niner

duplicate account, banned
Joined
Jun 3, 2011
OP, drive her Audi for a tankful, and have her drive your JSW for a tankful, and compare notes after a couple of weeks or so.
 

DubFamily

Veteran Member
Joined
May 30, 2012
Location
Swan Point, MD
TDI
2014 BMW 328D xDrive
First off: The Jetta TDI comes with 16 inch wheels; just wanted to confirm you have 17s on your's OP?

Second; the A3 weighs about 150 Lbs more auto compared to auto; so that will factor in as well

Third; According to VW's website, the '12 Jetta does not have a DSG, does your gear selector say DSG on it? Seems wierd to me. But if you look at all the specs pages on the VW site, any car with a DSG specifies "Available DSG" etc; while the base level Golf and the Jetta TDI both state "Auto with sport mode and Tiptronic".

A few things that could effect mileage quite easily ;)
 
Last edited:

chummer

Veteran Member
Joined
Dec 26, 2005
Location
Huntington Beach, CA
TDI
2010 A3 TDI Premium Plus/Titanium Package
After my HPDP failed and Audi install a new fuel system on my A3, my mileage have not been so great. I don't know why, maybe the new injectors need breaking in. It's been about 12k since the HPDP failed and it's not like before, hopefully it's just need to break in again?
 

rotts4u

Veteran Member
Joined
Aug 21, 2011
Location
California
TDI
None
First off: The Jetta TDI comes with 16 inch wheels; just wanted to confirm you have 17s on your's OP?

Second; the A3 weighs about 150 Lbs more auto compared to auto; so that will factor in as well

Third; According to VW's website, the '12 Jetta does not have a DSG, does your gear selector say DSG on it? Seems wierd to me. But if you look at all the specs pages on the VW site, any car with a DSG specifies "Available DSG" etc; while the base level Golf and the Jetta TDI both state "Auto with sport mode and Tiptronic".

A few things that could effect mileage quite easily ;)
I am not sure where you looked on VWs website but it does have a DSG on the TDI models as shown here on this info from VW

Leather-wrapped, multi-function steering wheel with shifter paddles (for DSG® automatic)
Technical
6-speed DSG® automatic transmission with Tiptronic® and Sport mode
Optional Features
First Aid Kit
TDI Appearance Package
Mat Kit
Protection Kit
Carpeted Mat Kit
Ground Effects Kit
Luggage Net
Splash Guards
TDI Mat Kit
 

DubFamily

Veteran Member
Joined
May 30, 2012
Location
Swan Point, MD
TDI
2014 BMW 328D xDrive
I am not sure where you looked on VWs website but it does have a DSG on the TDI models as shown here on this info from VW
Where did you grab that from?

http://www.vw.com/en/models/jetta/trims-specs.s9_trimlevel_detail.suffix.html/2012-Jetta~2FTDI.html

http://www.vw.com/en/models/jetta/t...e2|trimlevel=ce3194f265e2e218b8aff410903f159a

If you look at any "known" DSG vehicle the same page specifically says DSG on it. For the Jetta TDI it says "6 Speed Automatic" It may just be a typo or incorrect info, but that's why I was asking if your specific car actually says "DSG" on the shift selector ;)
 

WutGas?

Veteran Member
Joined
Feb 28, 2012
Location
Oklahoma City
TDI
The Last Real Jetta Sedan
It's a typo, or oversight. From your links, go to the "compare trims", go to the technical tab, and scroll down to the transmissions.
 

ruking

Top Post Dawg
Joined
Mar 27, 2003
Location
San Jose area, CA
TDI
2003 VW Jetta, 5 M, Reflex Silver: 09 Jetta, 6 Sp DSG, Candy White: 12 VW Touareg, 8 Sp A/T, Flint Gray
About 9 months ago I bought a 2012 JEtta sedan for myself and thus far over the 15500 miles I have averaged 40.5mpg hand calculated on fuelly. I liked it so much I talked my wife into getting rid of her BMW 135i vert and into an A3 TDI which she really like too.
Thus far I only have about 1600 miles on the A3 and the mileage on it is nowhere near the Jetta. I don't think she is as obsessed with mileage as I am so her driving habits may be slightly worse than mine but she also drives slightly more highway miles to and from work than I do. Thus far on three tanks she is averaging 34.5mpg. This weekend I even drove it on the interstate for about 200 miles and went sub 70mph and didn't get the normal 48-50mph (display) that I get on my Jetta when I do the same with no Ac running.
Both cars are DSG autos but they do have different tires with the Jetta running on bridgestones and the Audi on continentals. They may be different sizes too s I need to check that.
I know the engines are slightly different but I noted that on fuelly the A3 TDI just does not produce the same MPG as the Jetta TDi. Any ideas why anyone?
Not that I am complaining over 34.5 mph compared to the 20 mpg on the premium gas burning BMW but I expected more like 38ish.
First off the EPA's 30 C/42 H for both are exactly the same. Whether one or both of you can get EXACTLY the same mpg under similar or even to DIFFERENT conditions is academically interesting, but you have acknowledged they are different in the real world. You both in effect are documenting a 17.4% difference (-/+ 6 mpg). You have so many cross and competing variables that it is hard to assign consistent values to the different variables. It would appear that the underlying assumptions is that both of you post EXACTLY the same mpg, with different drivers and different conditions and at different mileages (new (1,600 miles vs more broken in (15,000 miles) and probably different tire sizes. Indeed, you have not posted an expected RANGE of differences. Now I am not saying that you can not achieve par nor even do better, but it will take a lot more coordination, albeit the "Taylor's" (who set the 84 mpg + record on a single Passat tank with an EPA H of 43 mpg., as lt applies to Jetta's 58 to 64 mpg)

So the easiest way is to take her (each others actually) car and drive it for a tank or two in each's situations (your commute). I suspect she will get close to 34.5 in her romps in YOUR car and you close to 40.5 in yours, in HER car. You can easily see if your mpg postings (in her car) matches your documented mpg @ 1,600 miles (in your car). Keep in mind you have 15k of break in and that easily can mean 1 to 3 mpg difference. Next it is well know that different tire sizes and widths (bigger) than oem normally DROPS mpg. The oem size for Jetta sedan is 205/55/16. Sizes for A3 (JSW) are BOTH wider and bigger 225/45/17, 225/40/18. This can cause variance, easily from 1 to 4 mpg. The part that is unknown, but I suspect CAN post the most variance are different drivers (0 to 10 mpg). Another is diesels have different parameters than gassers like the BMW. It is normally best to know what they are and operate within them. Not being used to the differences can mean 1 to 4 mpg differences. Another quirk that has been known for a long time are Sedans/ JSW's generally post slightly different mpgs. I have talked to many a TDI owner (@ GTG's) who have gone from the TDI sedan to a TDI JSW (A3) and can not figure out why the differences in mpg, 0 to 4 mpg. Just those differences alone, not counting driver and situation differences can easily account for the 17.4% differences.
 
Last edited:

rotts4u

Veteran Member
Joined
Aug 21, 2011
Location
California
TDI
None
First off: The Jetta TDI comes with 16 inch wheels; just wanted to confirm you have 17s on your's OP?
Sorry about the earlier post you are correct. The Jetta TDI does in fact have 16" wheels not 17" as I reported earlier. I am not sure of the circumference is much different between the two sizes so I will have to check that out to see if there is a significant difference which would of course effect final gearing etc.
 

bmike

Thread Killer
Joined
Jan 3, 2002
Location
central CT
TDI
1998 Jetta - sold, 2010 A3 - sold
Not sure if this helps, but my wife and I have actually done comparative mileage drives. Generally, she averages 5-7 mpg less than I do driving the same course (we drive from LA area to SF Bay Area to visit family several times a year - about 800 mile round trip). Personally, I think it is because she is not as smooth on the throttle, and does a lot of nervous type of on-off the throttle movements. She also will stay on the throttle to a stop or red light and immediately brake instead of coasting - I think part of that erratic throttle habit - she's just more of a nervous driver than I am.
If this is the case for the OP, your wife has pressitis. Driving with your foot always pressed, either on the gas or brake, (like F1 drivers), will lower MPG's; teach her the art of the coast. 10% gains are easily achieved.
 

rotts4u

Veteran Member
Joined
Aug 21, 2011
Location
California
TDI
None
If this is the case for the OP, your wife has pressitis. Driving with your foot always pressed, either on the gas or brake, (like F1 drivers), will lower MPG's; teach her the art of the coast. 10% gains are easily achieved.
I wish it was that simple but even with me driving the car on the interstate at a fixed and low speed like 68mph it just will not match my TDI jetta. I guess there is some difference other than the tires that is causing the difference in mpg
 

rotts4u

Veteran Member
Joined
Aug 21, 2011
Location
California
TDI
None
Well I figured out about 2mpg of the difference. Now the Jetta has almost 32000 miles and the Audi A3 is almost 11,000.

First all there is no (as is ZERO) statistical difference in either cars mileage now vs the first tanks in it. No break in improvement or anything like that. However, at about 29,000 miles on th Jetta I took off the stock Bridgestone EL400 tires and replaced them with MXV4 Michelins in the same stock size and the MPG of the Jetta did fall by approx 2 mpg. So now instead of the Jetta getting 46-48 on the interstate it is most like 44.xxx at a steady 70mpg.

My weekly 525 mile tanks on the Jetta have now fell to below 40 to about 39.xxx vs 41 before the tires. The Audi has the OEM Continentals so if they are even softer than the Michelins then there could still be another 1-2 mpg in the tires. Fuely is showing the cars much closer together now than before.

Once I change tires on the Audi I may go with the MXV4 or maybe the MXM4 H rated instead of the Vs I used on the Jetta
 

Nyaristo

Member
Joined
Dec 18, 2012
Location
Long island
TDI
2011 a3
I'm getting 39-40 on my A3 it 2011 that's just me in it and all i do is high way i have been getting 450 a tank with only 1 gall left
 
Top