I live in New England, and have kept a mileage-tracking spreadsheet on all of
our vehicles (for god only knows what reasons ;-) Over its life (I've owned it
since brand spanking new), my S4 has averaged an actual 20.56 miles per
gallon, while the computer-calculated mileage has indicated an average of
21.50 mpg. Not too bad an error rate (4.39%). All fuel used was at least 91
octane; and I'm guessing most of those miles were using 10% ethanol.
The vast majority of my S4 mileage has been on the highway, usually cruising
at around 85mph in top (6th) gear.
Are you driving an A6 S-line, or ? I expect the 6er is heavier than my car,
which might explain some of the difference...
'00 s4 6spd
Well, that's a little below the EPA estimates of 18/25, but, of
course, that's the old estimate that doesn't reflect real-world
driving like using the climate control, headlights, etc. Any codes
stored in the car? You can get that checked at Autozone for free.
Might not be a bad idea to make sure there is nothing going on that
might not be generating a CEL. I'm not sure how the computer
calculates the mileage but the old 'divide the elapsed mileage by the
number of gallons' is the best way to calculate it. My computer seems
to read a little high.
In my car I have averaged 22.78 mpg since new, 80% around-town
'04 A4 1.8Tq MT-6
Central NJ USA
When was the last time your sparkplugs and engine air filter were
replaced? If it's been a while, you may want to replace them. 18 mpg
seems a little low, but then again, it depends on how fast you drive.
Check the owner's manaul or the gas tank fill door to confirm the 2.7T
minimum of 91 Octane fuel. Being a twin turbo engine with knock
filling up with a lower grade fuel will definitely reduce gas
performance. Lower octane fuels also increase risk of
clogging up the fuel
system as well as increasing emmissions which is
harder on O2 sensors, EGT
sensors and all four of the the expensive
What is the vehicle odometer mileage?
Recommend a VAG scan to see if there are O2 sensor or EGT sensor codes.
O2's and EGT Sensors will reduce gas mileage. I replaced both
front O2's at 80K
KMs on 2.7T, they are primary feedback to ECU for auto
adjusting A/F mixture.
VAG-COM supports tests that can be performed to
check responsiveness of O2s,
they can become sluggish with age before
triggering DTCs and CELs.
I have a 2000 A6 2.7L twinturbo. I use 93 octane. My mileage is about
21-22 from a mix of local and highway travel. When I average just the
highway then the mileage seems higher ~25 and if it is local then it
falls to ~19. Once my average went to 17 or 18 even with enough
highway travel from 21. This went about few weeks and my car starting
shaking and I had to turn it in to a mechanic (decent one) and he
found lot of deposit on one of my valves. he opened up the engine,
replaced it and costed me a lot of money. I would recommend spark
plug change and engine cleaning to remove any deposits.
My 2000 A6 2.7T generally gives in the low 20's when at highway speed
(~ 70). City driving in the upper teens. The nice thing about a
relatively small V6 is that it will do well with gas mileage at
cruising. The MPG depends on how much you engage the loud pedal
(turbos). The power is there when you need it (to pass, etc.) but a
large displacement engine is not being pumped when not needed. Your
mileage may vary..
You call low 20s good gas mileage at cruising? Maybe for a 5-liter V10
engine. Most modern V6 and I6 engines can do much better these days.
Don't get me wrong, I know this 2.7tt is not your ordinary V6 and it
lots of fun, but good gas mileage is not one of it's strong points.
My 2004 A6 2.7T S-Line with 57,000 miles gets around 19 in mixed suburban
driving with a gentle accelerator pedal and about 24 on the highway. Of
course, when I'm having fun, it goes down to 14 to 16 mpg ... :)
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