jdbuddy

I have read many threads about fuel gauge issues, using Seafoam or Techron, and cross over problems, but I think my problem may be different.

My 2003 A4 only gets 240 miles per tank. The first half goes 160 miles then the second half goes fast. With an 18 gal capacity and 17 miles per gallon, I should get around 300 miles. I have been adding Techron for many tank fills and it has not changed. No visible leaks.

Could this be a calibration issue with the gauge? Is there a tuner that adjusts for this?

UM Rebel

I guess that depends on how and where you are driving. Any performance Mods? I have gone as far as about 425 miles on a full tank. That's Interstate driving at legalish speed. 2004 A4 no mods. I was on fumes when I got there.

Forcedvert

When it's on "E" how many gallons does it take to fill it back up that would tell you if it's a calibration/ gauge issue.

have you actually calculated your gas mileage?

I have the fuel gauge problem with mine it goes from not all the way full ( when full) to showing completely empty just passed half a tank.

I am a bit confused are you asking about the gas mileage or are you asking about the gauge accuracy.

Shaolin Crane

Most to a tank was 619 miles on the way back from Texas when I bought it, took around 18 gallons IIRC. But, even when the low fuel light comes on it's never taken more than 15 when it's driven around town. Long drives seems different.

JR-01

34 miles per gallon?

Shaolin Crane

When I did the math it was 33.xx, 6th gear, 70mph for a loooooooooong time.

I pretty regularly get 30-31 to Vegas and SD, 20ish around town/mixed.

johnsos30

My old 99 couple with LT headers, LS6 intake, small cam, and tuned was getting 31-32 on the highway and 24-25 around town.

Forcedvert

You guys are not driving your car right

Tsumi

I have found that if there is about 2-3 gallons (1/8) left in the tank, it would go straight to empty upon starting up. Also, the second half does tend to go faster than the first half, I think half tank fills about 10-11 gallons. I'm usually able to get at least 300 miles though.

Vetteman Jack

I can average 25-27 mpg in almost every tank of gas in my A4. So that would be 400-425 miles per tank, or close to that.

UM Rebel

Sounds like M6 get better mileage than A4. Best I've gotten with A4 is about 28mpg on highway trip.

Tsumi

Overall ratio on the last gear is 1.911 for the 2.73 final drive gear on the A4, and 2.205 if you opted for 3.15. The M6 has an overall ratio of 1.71 for coupes and convertibles, and 1.9152 for the Z06. A4 ends up cruising at a higher RPM than M6.

Shaolin Crane

I'm lucky to get 12 on the track, is that better? No need to drive like that on the street. Track is minutes away with bi weekly events.

jdbuddy

When it is on E it can only take 14.4 gallons max. I have not driven it to where it shuts down, so I don't know if it could use the whole 18 gallons.

Riteaidkid84

I fill up, go like 50 miles and half my tank is gone. Haha

but I don't drive much so when I do I do

soofrsh

390-420 per tank

Lazarus Long

If the gauge in the corvette is anything like my Tahoe, it is not linear. In my Tahoe, the needle doesn't come off F for over 50 miles, after 200 miles it is at half, then that last half goes quickly, it is getting close to E after about 330. So the first half is really 2/3, the last half is 1/3. This is city driving.

Yes I know the corvette has 2 tanks, but seems like the 2nd half goes much quicker than the first too.

In any case, you should be getting more than 240 miles from a full tank(s).

When you fill up after driving 240 miles, how much are you putting in?

Lazarus Long

Do different years have different capacities? The manual for my 98 states 19.1 gallons. (Going from memory. I'm out f town now)

Lazarus Long

240 miles/14.4 gallons = 16.7 mpg. That doesn't seem terribly unreasonable for city driving.

Tsumi

http://www.z06vette.com/forums/f5/ho...m-works-60056/

Rather fascinating read into how the system works. Seems needlessly complicated to me.