12 A3 TDI vs 12 Jetta TDI MPG

[rotts4u]

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]

Originally Posted by rotts4u

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]

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]

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]

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]

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]

Originally Posted by rotts4u

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

[chummer]

Why is the A3 so heavy compared to the Jetta/JSW they're bigger cars?

[WutGas?]

Originally Posted by chummer

Why is the A3 so heavy compared to the Jetta/JSW they're bigger cars?

The 2011+ Jetta is very slimmed down if you want to call it that. The A3 I believe weighs roughly 200lbs more than the Jetta.

[chummer]

I would like our car to be a little lighter.

[chetdi]

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]

Are the dsg's geared the same? Maybe the A3 is geared more for sport rather than fuel economy.

[Eurosport]

Originally Posted by sledstorm1

Are the dsg's geared the same? Maybe the A3 is geared more for sport rather than fuel economy.

gearing is the same ratios on both...

[Niner]

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.

[pushgears]

After 2500 miles of mixed driving, My 2012 A3 is averaging 37.5 mpg.