How does the A7 determine estimated fuel range?

[rbpeirce]

On the highway in VA I may get as high as 32mpg. Around town in PA it drops into the teens. Starting from PA, before a trip I add enough fuel to get to VA where prices are lower. I usually figure about 25mpg starting with the estimated ange, but it seems to have a random effect on the updated estimated range.

[Valpo A7]

The car will estimate the fuel remaining in the tank and apply the average recent fuel economy to guess at the distance to end of tank. I want to say it takes a sample of the last 20 30 minutes of driving.

Highway I can get a bit past 400 miles to where I feel comfortable to extend my range to for a pit stop. It will go more than that but my bladder does not always agree with traveling further. Distance between pit stops drops when I have more than just my bladder to deal with.

On the highway the car is going at a constant speed with a constant fuel consumption. Around town it is normal for the fuel economy to drop as you accelerate, decelerate, and stop to idle at stop signs and stop lights. The lighter on the go pedal you can be the higher your estimated fuel economy can be around town.

[Audisthesia]

That DTE estimate is always going to be wrong. Best to observe personal tank avg and go with that.

[rbpeirce]

Depending on how good the initial estimate is my 25mpg rough rule-of-thumb has worked pretty well. I was just hoping for something a little better. If the initial estimate is too high I may have to splash-and-dash in WVA but usually I'm okay.

This is mostly a game for me, gas enough to get from PA to Winchester, gas enough to get from Winchester to Waynesboro and then top up based on Gas Buddy. My wife thinks I'm nuts. I actually came into Waynesboro once with 20 mile range on the clock, which is better than running out on I-64!

I also top up in Winchester heading North. If I don't use the car much in PA I usually have almost enough gas to get back to Winchester. Fun.

[Alabama]

I was just hoping for something a little better.

Terrain also makes a difference. I can imagine in several years mapping and traffic monitoring software will be sufficiently improved so that a routing will also predict fuel use for speed limit driving.

[GilliamOS]

How does the A7 determine estimated fuel range?

Poorly.

[JWebb_C7_Comp]

Poorly.

I pulled off highway into Costco two weeks ago. Filled 17 ish gallons when the car estimated 10 miles remaining. That suggests Audi is conservative but I’ll NEVER go that low of estimated miles remaining!!!!

I’d prefer to fill at about 30 remaining - or 1.5 gallons…


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[Valpo A7]

I’d say it’s about 1.5 to 2 gallons remaining in the tank when the low fuel chime kicks in and asks if you want to navigate to the nearest gas station. Now our old Jeep, when the low fuel light comes on that ****** was on fumes. Had it come on once and I drove about 20 miles to get off the highway to a gas station. I put 14.7 gallons in a 14.5 gallon tank.

[Alabama]

I’d prefer to fill at about 30 remaining - or 1.5 gallons…

In another AZ thread a comment was made about a pump within the tank that uses the surrounding fuel as a "heat sump". The suggestion was that letting the fuel level get too low would cause that pump to run hot, shortening its life.

[Valpo A7]

In another AZ thread a comment was made about a pump within the tank that uses the surrounding fuel as a "heat sump". The suggestion was that letting the fuel level get too low would cause that pump to run hot, shortening its life.

.

I have read that statement many times however I have been driving since 1984 now and have routinely driven may all of my cars to the point that I fill up close to E. In 39 years of driving now I have never burned up a fuel pump from it. In all this time I have only changed 1 pump that actually quit and it turned out to be a broken wire. Another pump broke a fitting on the connection line.

[rbpeirce]

I’d say it’s about 1.5 to 2 gallons remaining in the tank when the low fuel chime kicks in and asks if you want to navigate to the nearest gas station.

That sounds about right. I normally see about 40mi range left, give or take.

[Alabama]

I have read that statement many times however I have been driving since 1984 now and have routinely driven may all of my cars to the point that I fill up close to E. In 39 years of driving now I have never burned up a fuel pump from it. In all this time I have only changed 1 pump that actually quit and it turned out to be a broken wire. Another pump broke a fitting on the connection line.

Likewise, I've never had a pump fail; maybe just lucky. Up north the advice was to keep the tank relatively full in the winter to minimize water condensation and possible icing.

[Dave4501]

When I fill my A7, it tells me I have a 500 mile range which is way higher than actual. So, the estimate seems to be a bit too optimistically calculated.

I would guess I have about 2 gallons left when my low level light comes on. I can easily go 40 miles without much concern.

[Audisthesia]

.

I have read that statement many times however I have been driving since 1984 now and have routinely driven may all of my cars to the point that I fill up close to E. In 39 years of driving now I have never burned up a fuel pump from it. In all this time I have only changed 1 pump that actually quit and it turned out to be a broken wire. Another pump broke a fitting on the connection line.

Likewise, I've never had a pump fail; maybe just lucky. Up north the advice was to keep the tank relatively full in the winter to minimize water condensation and possible icing.

Exactly my experience as well.

[paul-g]

i live in the north and condensation is none issue with fuel injection it just shoves it thru not like carb cars. I have never had any issues BUT i'm also the guy that normally tries to fill t 1/4 tank but doesn't always happen

[was003]

default avg consumption estimates are done based on 15 mins window, you can code it to be longer (20, 30, 45min). Based on my observation, the remaining distance is measured by taking the last avg estimate and current fuel amount, then rounding it up to full 10s (kms in my case, but I don't expect it is different for miles)

[AudiInMyA7]

My tank always says i get 420 (giggity) - 450 a tank when full but i barely ever see above 300. That shit is dead wrong and idrk how it guesstimates DTE


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[was003]

My tank always says i get 420 (giggity) - 450 a tank when full but i barely ever see above 300. That shit is dead wrong and idrk how it guesstimates DTE

remember that the estimate accounts for all the tank's volume, and you usually refuel when 10l+ (or 3+ gallons) are still there, hence you never reach the estimated value. These numbers are pretty accurate when doing highway miles, but the minute you get in a traffic, its accuracy become like becomes like reading tea leaves to predict the future...

[rbpeirce]

Mine is actually pretty accurate. My problem is after driving around town for a couple of weeks I take a 315 mile trip and have to decide how much high price fuel to buy to get to the low price fuel [Gas Buddy]. My approach has been to take the posted range and allow about 25 more miles for each gallon I add. This always over-estimates how much fuel I need but I can't figure what to do about it so I don't.