V6 mpg

[Dstenersen]

Hello again PW. I have been tracking my MPG for some time now and come to the result that I get about 16 mpg in town and 24 mpg on the highway. i get about 280-320 miles per tank. Now, ive noticed through some searching that some v6 owners are getting 30-35 mpg highway and roughly the same in town that I am getting. Im wondering how this is possible. I run only 91 octane fuel with no ethanol. 0w-40 fully synthetic oil. I also baby the hell out of my gas pedal. There are no codes as far as I know except a code in my climatronic for a temperature flap servo motor. I have a 2003 V6 Passat GLX 5 speed. Does anyone have any insight?

[y2000passat]

4MO or FWD? I can get close to 30 mpg hwy at 65-70 mph with 87 octane fuel with my '00 V6 5spd FWD. You'll do much less with 4MO.

[Dstenersen]

sorry i have a FWD. I drive primarily highway at a constant MPH

[asteele.19]

I get 20 around town and 24-26 on the highway. you don't seem that far off. I have a hard time believing people that get 30mpg out of there V6 on the highway.
A lot of it isn't consistent speeds, its how fast you get to those speeds lol ive noticed that in 5th gear in the manual transmissions you are still revving pretty high. Maybe different years having different gearing???

[TheColoradoRed]

I had a 31.7MPG average on a 800+ road trip in my 2.8, I think you should be seeing more than 24MPG.

You can do all the little things that might up effeciency: check tire inflation, change fuel filter, change air filter, change spark plugs, clean throttle body, etc. Other than that.. Just coast a lot

[Dstenersen]

I'm sure the fuel filter has never been changed. Looks like a straight forward job. it doesn't seem like the previous owner did any regular maintenance at all

[ylwagon]

People tend to home in on the fuel filter or air filter, but neither of those will affect cruise MPG unless horribly clogged. The engine compensates for fuel pressure restrictions to an extent, because the O2 sensors have the final say-so. A restricted air cleaner is just less throttle opening as far as the ECU is concerned. More important are things like tire condition and pressure, alignment, dragging brakes, etc. I've gotten as much as 30 MPG with my 2.8 A4, but more typically average 24~25, which is mostly freeway.

[2002GLXV6]

People tend to home in on the fuel filter or air filter, but neither of those will affect cruise MPG unless horribly clogged. The engine compensates for fuel pressure restrictions to an extent, because the O2 sensors have the final say-so. A restricted air cleaner is just less throttle opening as far as the ECU is concerned. More important are things like tire condition and pressure, alignment, dragging brakes, etc. I've gotten as much as 30 MPG with my 2.8 A4, but more typically average 24~25, which is mostly freeway.

2X on this.

I have read several posts here on PW about changing the fuel filter and getting improved mileage and I just do not see how that is possible. I think this is just a placebo effect. After you change the filter you are tracking your mileage and slightly alter your "normal" driving habits. You would have a loss of power and stumbling on acceleration if the fuel filter was a problem. My mileage is usually 17ish around town and 28-31 on the highway. If I drive fast and do a lot of passing on highway trips the mileage is lower. And I am a firm believer in clean shiny cars are faster and get better mileage.(probably again a placebo)

More than likely the cause of differing mileage is simple things like driving habits, traffic and tire pressures. Start checking your tire pressures every two weeks for a while check your mileage. By the way what tire pressure are you running? If you are running the "normal" 28lbs as stated on the gas door try running 30lbs. Tire Tech Information - Air Pressure, Temperature Fluctuations

Gas Mileage Tips - Keeping Your Vehicle in Shape
Gas Mileage Tips - Driving More Efficiently

An aging O2 sensor that is sending a false lean condition to the computer and tells the engine to run a richer fuel mix could be a cause of poor mileage. Also a dirty fuel injector could cause a similar result. One or two cylinders running lean causing the O2 sensor to send a lean message which would again cause the remaining cylinders to run rich trying to make up for the lean condition.
My mileage would aways decrease in the winter when I lived in Maryland because of the which to Oxygenated Gas.

2002 GLX V6 5sp manual

[BroSpeed11]

I drive a 2003 V6 4MO with 110K miles on it, I am the second owner and I am currently getting about 17mpg city/20mpg highway with my car running 87/89 octane fuel. just thought i'd chime in with some 4MO input on the mpg.

[TheColoradoRed]

People tend to home in on the fuel filter or air filter, but neither of those will affect cruise MPG unless horribly clogged.

That's why I offered it as a suggestion: if they haven't been replaced in years they could be horribly clogged..

An aging O2 sensor that is sending a false lean condition to the computer and tells the engine to run a richer fuel mix could be a cause of poor mileage. Also a dirty fuel injector could cause a similar result. One or two cylinders running lean causing the O2 sensor to send a lean message which would again cause the remaining cylinders to run rich trying to make up for the lean condition.
My mileage would aways decrease in the winter when I lived in Maryland because of the which to Oxygenated Gas.

x2, could very well be misreadings from a faulty 02 sensor. You can monitor and test the sensor in VAGCOM to determine if that is the cause.

I drive a 2003 V6 4MO with 110K miles on it, I am the second owner and I am currently getting about 17mpg city/20mpg highway with my car running 87/89 octane fuel. just thought i'd chime in with some 4MO input on the mpg.

Yup, 4mo mileage sucks.

[uksparky]

2001 V6 ...25 mpg hwy.. 65/70mph

[koidragon1980]

I can only hit the 30+mpg mark if I'm driving for extended periods of time (3+ hours) on an open highway with no traffic or street lights to bother with. Otherwise, my #s are very similar to the OPs.

general tune-up/maintenance before a long trip can help (oil, plugs, filters, tires). the occassional treatment of Techron will give me a slight boost in mpg for a couple of tanks as well.

[tallngangly]

Seems odd that nobody ahs mentioned transmission type yet... Most of the time manual transmission vehicles will get significantly better mpg than autos (even when the EPA estimates are close). I get about 25 mpg highway with my 2000 V6 auto wagon.

[ashman78]

We've got a 4mo Tip wagon and a 5MT FWD sedan -- polar opposites in the B5 world.

Almost a decade of testing:

5MT FWD: 18-22 in the city, up to 30 on highway (usually more like 28). If you're getting over 30mpg, it's downhill and favorable weather
4mo Tip Wagon: 15-17 city, rarely over 24 highway. Ditto on anything higher.

This isn't far from the original EPA stickers, and it's above the "revised" EPA stickers. No big surprise there.

[ylwagon]

Seems odd that nobody ahs mentioned transmission type yet... Most of the time manual transmission vehicles will get significantly better mpg than autos (even when the EPA estimates are close). I get about 25 mpg highway with my 2000 V6 auto wagon.

That's not so true as it used to be, because the lock-up clutch in these torque converters reduces the energy losses to basically just the ATF pump. That I suspect is why the manual/automatic highway mileage ratings are only about 1 MPG apart. Also, and correct me if I'm wrong, the final drive gear ratio is higher with the automatic. My 2.8 A4 turns just under 2,000 at 60 MPH.

[vwb5t]

usually 20-22 combined, i can see up to 26 if i light foot it and stay out of the boost

[smitty40]

The only way to get 32 mpg in a v6 fwd 5speed automatic is on flat highways and keep it below 55 mph which is typical here in Houston during rush hour. this assumes your car is in good mechanical condition and no vacuum leaks and you are running 91 octane or above. I can get 32 mpg travelling back and forth to work which is 25 miles each way, but if I drive 65+ miles per hour my mileage goes down to 29-28. In stop and go driving I get closer to 21 mpg. On the v6 ATQ motor it is important to replace all vaccum lines, even the 7mm one that is under the plate where all the vacuum lines come together.
http://www.passatworld.com/forums/at...7&d=1357165905

[Dstenersen]

People tend to home in on the fuel filter or air filter, but neither of those will affect cruise MPG unless horribly clogged. The engine compensates for fuel pressure restrictions to an extent, because the O2 sensors have the final say-so. A restricted air cleaner is just less throttle opening as far as the ECU is concerned. More important are things like tire condition and pressure, alignment, dragging brakes, etc. I've gotten as much as 30 MPG with my 2.8 A4, but more typically average 24~25, which is mostly freeway.

My car has 110k on it and probably needs a new fuel filter anyways. might as well do it before it does get clogged

As far speed goes. I drive a constant 70 mph (the speed limit) for about 45 mins at a time. RPMs are just under 3000 in 5th the whole way and it is mostly flat. I am a stickler for tire pressure because my job is a tire technician . ive had the rear brakes replaced recently and the rotors needed to be resurfaced. as far as alignment goes, I have not actually ever had it checked. Im putting it on my checklist for the holidays

[Dr No]

24.5 mph at 80 mph this past week. V6 auto with the cruise on. Much better when I'm going slower.

[TWhite]

I have a 2003 V6 Passat GLX 5 speed. Does anyone have any insight?

I have the same car and I average between 28-29 in mixed driving (35 mph average speed). I'm not sure how accurate the computer is though... Check the slush screen to make sure it isn't clogged, I removed mine. Also, it's better to leave it in gear when decelerating, some people I've seen will throw it in neutral.