Hi,

I have a 2006 A4 Quattro sedan that I purchased a little over a month ago. I absolutely love it and it's a huge change from my pickup that I was driving before this. I'm a little disappointed in the fuel economy however. Audi is saying it should get 22 mpg in town, and 30-32 mpg on the highway. I do a mixture of the both, but even when most of my driving is on the highway I've only managed to get about 21.5 mpg. I can accept that Audi's figures may be a little high for the mpg ratings, but I still think I should be getting better mileage than 21.5 mpg.

I had the oil changed in it after I purchased it, and I used synthetic oil. I also ran some BG 44K fuel system/injector cleaner through it and that didn't seem to help. Just last week I changed the fuel filter in hopes that would improve the fuel economy, but so far it doesn't seem like it's helping. Anyone have any suggestions or knowledge on this topic?

Also, I've read a lot about PCV vales and diverter valves having problems and updated parts. What the deal with that?....any issues there that might correspond with my poor fuel economy? Please let me know.

 

I've had both my DV and PCV fail, with no noticeable impact on mileage. I also get 21.5 MPG overall, but my daily commute is less than 10 miles.

 

30-32 mpg on the freeway doesn't look right. For the 2007 Quattro, the
expected (according to Audi): 22 in city, 26 on freeway. I get little less than this,
because of my driving style I think. My wife gets much better mileage than me :-)
If on cruise control on freeway, sometimes I've noticed more than 26 also.

21.5 on freeway means something is wrong, have it checked.

 

i cant really think of anything serious but have ya checked the little things like tire pressure, the type of gas your using, weather conditions, road/driving conditions?

my 2008 can get 30mpg on long highway trips but low 20s in the city. my school commute includes some long hills that kill my average (the realtime is 6-7mpg in 5th gear at 45mph uphill lol) but this winter iv also noticed a 2-3mpg difference depending on the temp outside. anything above 35degrees seems better.

 

More info would be helpful such as the terrain you drive and how many miles the car has. Did you try replacing the plugs?

 

fuel filter would be the only major upgrade to the fuel eco.......when i changed mine... it shot up for a while..... rims or bigger wheels... play a factor. avoid. short trips.... u waste alot of fuel.. juststaring it up... cuz your getting real crapy mileage till your beast is warmed up

 

I live in Colorado next to the mountains, so it's high elevation, around 5,000 ft. But most of my driving is done either in town or on the highway/interstate, and it's pretty flat for the most part. There are some rolling hills but nothing very steep. My drive to work is about 20 miles one way, so about 40 miles round trip. On days when I carpool I only drive 8 miles one way, or about 16 miles round trip. Maybe that isn't far enough?

My car has got 45,000 miles on it, I bought it used but it looks like it's been well taken care of. It has no modifications performance wise, it still has the stock rims/tires and suspension components. I take good care of it and try to keep it maintained, and check the tire pressure frequently. I've never changed the spark plugs in it yet. The maintenance guide says it doesn't need to be done till 55,000 miles, but I was gonna change them at 50,000. Maybe I should just change them now...do you think it would make much difference in the fuel economy? Also, I always use premium fuel when filling up(91), and I use Shell gasoline. I always found with my other vehicles that the higher octane you use, it would typically get slightly better fuel economy.


Thanks everyone for all the helpful suggestions!

 

Possibly. When you take them out, take a look at their condition. It doesn't hurt to change plugs a little early.

 

Remember, in 2008 the government recalculated how a car's milage sticker was computed to get a more realistic rating. It typically dropped a cars milage 2 to 3 mpg. A 2006 2.0t quattro manual was rated at 31 on the highway. That same car in 2008 was rated at 29 because of the new calculation method. Also remember if you do city miles the milage can fall of quick. These cars are fat little porkers. The car is about 4000 lbs. Quite heavy for a car it's size and class, and that hurts milage. Also high elevation means thinner air, which can affect performance and milage.

 

I also have a 2006 A4 2.0T Quattro. I do about 35,000 miles a year as I am in sales. On a recent trip to Florida I got 27.5 MPG driving at some pretty fast speeds (80 + MPH) and was stuck in several traffic jams that lasted an hour or more.

On the job, I get 26.5 to 27 mpg in and around Boston. I'd say I do about 25% city and 75% highway. I have checked in town fuel usage and I've seen it as low as 18 mpg, but most time around 20.

I get the best mileage by using the cruise control, which when used over a distance of 50 miles or more at speeds of around 60 to 65, I get 30 mpg plus. I don't do that often as it get a little boring.

I'd check the plugs, air-filter, diverter valve, and the PCV. Also make sure the coolant temperature sensor is working. After the car has warmed up, goose it as it is in neutral at a stop and see if you get black or gray smoke. That would indicate a rich mixture.