Gas Mileage...

[JHousyS4]

I feel I am at the gas station way too much. What's everyone average MPG on their s4 2.7t. Those turbos sure are hungry for some 91 oct. i get 14.5-15.5 usually. SO SH1TTY...what can i do?

[duffS4]

Wow, that's pretty low. I get around 18/19 in the city and 23/26, depending how heavy my foot gets, on the highway.

[mullarks]

19.88 mpg on my last fill up.

[JHousyS4]

I dont have a heavy foot, but when the opportunity is open i take it...im cruising, but i shouldnt be getting that low of a average MPG. i NEVER use the air either.

[TJ00S4]

WOW, that is really low.... I average 20.8MPG....

[JHousyS4]

Then WTF...what do i do?

[s4Rye]

Originally posted by JHousyS4
Then WTF...what do i do?

That's a bit low. Maybe add some fuel injector cleaner in there and see what happens.

[JHousyS4]

if i buy some fuel injector cleaner, do i have to put it in on a full tank of gas?

[TJ00S4]

Normally you do, yes... just read the bottle.

[JHousyS4]

So i get gas...fill it up, as the bottle reads, thanks ^...without u id be lost. Anyways, i reset the MPG after getting gas. I drive like a girl all the way home to get the average of 16.4! YEA But if i was driving like normal- i wouldnt be surprised to be back in the 13's. Any other ideas?

[Ben@SpeedBarn]

well you gotta give the cleaner till the next tank to see the difference.

[aussie_s4]

How's the tire pressure? Mine are usually 38psi all round.

[JHousyS4]

Originally posted by aussie_s4
How's the tire pressure? Mine are usually 38psi all round.

[JHousyS4]

Originally posted by aussie_s4
How's the tire pressure? Mine are usually 38psi all round.

Does that really make a difference? I bought the car..certified...from KEYES AUDI, about 2 months ago.

[dramaticstatic]

Tire pressure makes a big different in both gas milage and handling.
Check it every week or two. 38 psi is a good setting.

Also consider resetting your mass airflow sensor.
It really sounds like yours is either not calibrated right or clogged up.

Someone may need to correct me on this one but I believe you remove the negatvie wire from the battery and let the car sit like that for 30 mins.

I average about 19.5 with mixed driving.

[TJ00S4]

My mass airflow sensor went bad and after I replaced it I went from 19MPG to 20.8MPG average.... something is definitely messed up somewhere....

[JHousyS4]

What should i try? Should i unplug my negative battery sensor and let it sit? Should i go to the dealer?

13 MPG is not alright. i gotta do something about this.

[QuattroCoryG]

how does how much air you have in your tires effect gas milage?

[illusive45]

I have been averaging between 17-22MPG, depending on how hard I drive. I have a frequent lead foot, but I usually get to top gear as soon as possible when I reach highway speeds.

Tire pressures have a lot to do with mileage. When a tire doesn't have enough air, it has more resistance. More air, less resistance. Its simple physics, fellas. Keep your tire pressures above 36 at the least.

[JHousyS4]

14.6 MPG!! half tank left with the fuel injector cleanser.

Perhaps does the remus muffler/exhaust system have to do with it maybe?

[dramaticstatic]

Go to the dealer and tell them something is wrong with your maf.
They should be able to make everything hunky dory.
Pulling the negative battery terminal is not really the best thing to do because it will cause a low voltage fault and may raise some suspicions that your car is chipped and you're swapping out ecu's.

[JHousyS4]

Originally posted by dramaticstatic
Go to the dealer and tell them something is wrong with your maf.

"maf" is that short for manifold?

[bitterchild]

mass air flow as in mass air flow sensor. You may need to check you tuneup schedule. Also the tire pressure. You do realize at speeds above 55mph or so using a/c is more fuel effecient than cruising around w/ your windows down.

[dramaticstatic]

Originally posted by JHousyS4
"maf" is that short for manifold?

Sorry maf is Mass Air Flow sensor.
You could have a bad maf or it just needs to be reset.

What year is your car?

[aussie_s4]

Originally posted by QuattroCoryG
how does how much air you have in your tires effect gas milage?

It plays a part in the car's "rolling resistance".

When the tire is more flexible, there is more friction against the road, more effort is required to roll them and more kinetic energy is converted to heat and sound.

Rolling Resistance from Tire Rack's website
A vehicle's fuel economy is the direct result of its total resistance to movement. This includes overcoming inertia (Newton's Law), driveline friction, road grades, tire rolling resistance and air drag.

During stop-and-go city driving, it's estimated that overcoming inertia is responsible for about 35% of the vehicle's resistance. Driveline friction is about 45%; air drag is about 5% and tire rolling resistance is about 15%.

Overcoming inertia no longer plays an appreciable role in the vehicle's resistance during steady speed highway driving. For those conditions it is estimated that driveline friction is about 15%; air drag is about 60% and tire rolling resistance represent about 25%.

[JHousyS4]

Alrighty, first things first. I go outside today and grab a tire gauge. Each tire is 32 psi or under. I go to the nearest 76 station and fill each tire up to 36/37 psi. On my ride home my mpg dropped from 14.5 to 14.3.
Tomorrow i will head over to Audi and ask about the Mass Air Flow Sensor. Should i have it replaced or reset? Is it covered on warranty?

[JHousyS4]

my car is an early edition 2001. I jsut bought it certified about 2 months ago

[aussie_s4]

Your car is certified, but in case anyone here has problems with their MAF sensor, Audi has extended their warranty for mass air flow sensors to 7 years or 70,000 miles, whichever occurs first, from the vehicle's original in-service date. Or if you've previously paid to have yours replaced, you can request reimbursement from Audi.

Subject: Warranty Extension LR
Mass Air Flow Sensor Warranty Extension for:
- 2000-2001 Audi A8 4.2L Vehicles
- 2000-2001 Audi A4 1.8T Vehicles
- 2000-2001 Audi TT 1.8T Vehicles
- 2000-2001 Audi A6 and S4 2.7L Bi-turbo Vehicles

Dear Audi Owner:

As part of Audi's commitment to our encironment, we would like to inform you of our decision to extend your Emissions Control Systems Warranty for a mass air flow sensors to 7 years or 70,000 miles , whichever occurs first, from the vehicle's original in-service date.

The vehicle's original in-service date is defined as the date the vehicle was delivered to either the original purchaser or the original lessee; or if the vehicle was first placed in service as a "demonstrator" or "company" car, on the date such vehicle was first placed in service.

The mass air flow sensor is an important emission control device which, in the event it malfunctions, causes the MIL light on your instrument panel to come on and may adversely affect the drivabliity of your vehicle. For additional information concerning your Emissions Control Systems Warranty, please consult your WArranty Booklet or your dealer.

If the mass air flow sensor in your vehicle malfunctions, your Audi dealer will replace it without charge, as long as the vehicle remains within the above time and mileage limits.

Please keep this letter with your Warranty booklet and deliver it to any new owner, along with the Owners Manual.

If you have previously paid for the replacement of the mass air flow sensor, the enclosed ofrm explains how to request reimbursements. We would be pleased to review your reimbursement request.

We are pleased to offer this extended emissions warranty and hope that you will continue to be a member of the Audi family. Thank you for driving an Audi!

Sincerely,

Marc R Trahan
Director, Audi After Sales

Warranty Extension for Mass Air Flow sensor - AZ Audi link

[jnPimp-s4]

how do u check ur gas mileage? sorry im a newbie

[dramaticstatic]

Originally posted by JHousyS4
Alrighty, first things first. I go outside today and grab a tire gauge. Each tire is 32 psi or under. I go to the nearest 76 station and fill each tire up to 36/37 psi. On my ride home my mpg dropped from 14.5 to 14.3.
Tomorrow i will head over to Audi and ask about the Mass Air Flow Sensor. Should i have it replaced or reset? Is it covered on warranty?

Hope all goes well for you.
Just have the thing replaced.

[Live2Ski]

Originally posted by jnPimp-s4
how do u check ur gas mileage? sorry im a newbie

Take the miles you drove divided by the gallons it takes to fill up your tank.

[TJ00S4]

Think about how hard it is to push a car or pull a trailer with a flat tire.... low tire pressure has the same effect, just not to that extreme...

[TJ00S4]

"Alrighty, first things first. I go outside today and grab a tire gauge. Each tire is 32 psi or under. I go to the nearest 76 station and fill each tire up to 36/37 psi. On my ride home my mpg dropped from 14.5 to 14.3.
Tomorrow i will head over to Audi and ask about the Mass Air Flow Sensor. Should i have it replaced or reset? Is it covered on warranty?"


They covered my mass airflow sensor outside the factory warranty, I think this is a common failure and they are taking care of it.. If they try and make you pay for it push them harder.

[JHousyS4]

WELL -- Right now my tires are good and drove to Santa Barbara. Now I am at 16 MPG. But that is just because i was driving fast. (BTW i made it home in 51 minutes according to the audi timer.) But tomorrow i am going to AUDI d and get my mass air flow sensor replaced! TO BE CONTINUED...

[illusive45]

Originally posted by jnPimp-s4
how do u check ur gas mileage? sorry im a newbie

Oh boy...OK, on your next fill-up, reset your trip odometer. Drive the car until you need gas and fill the gas tank again. Divide the total mileage from the trip odometer by the amount of fuel you added on that fill-up. Shaboooya! You got your gas mileage.

[Hassmeister]

Originally posted by JHousyS4
I feel I am at the gas station way too much. What's everyone average MPG on their s4 2.7t. Those turbos sure are hungry for some 91 oct. i get 14.5-15.5 usually. SO SH1TTY...what can i do?

Get a 1.8t A4 and mod it like I did. I get 34 HWY.

S4 and gas mileage... somehow the two don't go together.

[dramaticstatic]

Originally posted by Hassmeister
Get a 1.8t A4 and mod it like I did. I get 34 HWY.

S4 and gas mileage... somehow the two don't go together.

My S4 is actually quite decent on the Highway.
The problem comes in stop and go traffic. That just absolutely kills gas mileage.

I average about 19.5 mixed, sure it's not the best but it is just about how much I got with my old '97 BMW 5 series and my S has way more power.

If you're not flooring the car at every stop then you shouldn't be getting less than 17mpg otherwise something is definitely wrong.
On 2000's and early 2001's the Bosch MAF's go bad a lot.

[10SecS4]

I recently purchased a pretty well beat up red 2000 Tiptronic S4. I got an excellent deal on it and am using it as a daily beater right now.

Anyway, according to the trip computer, I averaged 21 to 21.5 miles per gallon on the way back from the casino last weekend where I was doing an easy 75-80 MPH. Does that sound about right? I was thinking it was pretty low until I checked some of the other responses on this thread...

[Jooce]

I drive in 6th gear any chance I get. According to the Real Time Gas meter, I'm getting roughly 32 mpg in 6th @ ~45mph. ~38mpg in 6th at about 65mph. Its the stop & go driving part get sucks... car eats gas until you get it in at least 4th gear. Otherwise i'm in the 15-22mpg range.

[JHousyS4]

But i cant even get above 15.9. I drove to Santa Barbara going 100-120 and the most MPG i got was 15.9--my peak. Usually im down in the low 14's around So Cali.