the flyin' scotsman

2 things trigger this question. Nicole recently posted pics of some interesting numbers that also indicated the MPG of her car as well as I looked at a fellow Canadian's '89 S4 yesterday who's car displayed 397km to go and he still had half a tank.

Now, if I get 400km per tank I'm around average although I do confess to running the car as designed speed wise. BTW this 'mileage' hasn't really changed since owning the car and all the work I've done although in thinking of the performance gains I've achieved and the mileage remaining similar that would indicate better economy!

fabric

On a somewhat recent trip to Rochester MN, I ran until the fuel light went off, and then some. I think it was 437 miles, and IIRC I put in 21 gallons? Numbers are fuzzy, but I that worked out to a bit under 20 MPG, with a solid 1.5 hours at 90, and the rest at 70-80. Speedo may be a little high. EPA was 19 highway, 22 gallon tank, my numbers aren't that out of line with some accounting for speedo inaccuracy. Although the odomete was pretty close to the distance Google gave me to Rochester.

Based on the highway driivng I've been doing, i seem to get 20mpg whether I"m going 70 or 90, but this is without cruise on somewhat to moderately busy highways, so I think a constant 70 might even see a little better. But in my limlited time with the car, highway MPG seems to be only mildly related to speed, although I have no data on extended miles beyond 90 mph. What do you ORR racers have to report on this front?

the flyin' scotsman

Yikes..........if we round your miles to 430 thats equivalent to approx 690kms.

Do I have a problem? Well there's no gas leaks, my MAF is a rebuilt unit from JDS which leads me back to my LH brain question I posted some time ago. All other maintenance items are in good shape air filter, plugs, etc etc.

Daniel Dudley

Malcom, I can drive from Albany NY to Washington DC on 3/4 tank, or I can blow a quarter of a tank just screwing around on local roads with a lead foot. what kind of driving are we talking here ?

IcemanG17

On my US 88 S4 Auto I typically get around 20-21 on the freeway and drive around 80mph (closer to 90)...in town I get around 14mpg.....my average tank (combined about 50-50) is usually 18mpg. I did get almost 21 mpg average during the Sharks at the Lake event (including the fun drive!)

Garth S

To determine fuel economy, it remains difficult to beat the simple recording of total distance traversed verses the volume of fuel added: the 928 fuel gauge is about as accurate as its voltmeter, so is about as useful as a sundial at night.
At a 125-140Kmph cruise, I find the S4 to yield a reliable 10l/100Km - quite impressive IMHO for a '80s 320 hp.

BrianG

Malcolm, on our recent trip to Kalispell, Rich ('85 5-sp) and I ('87 auto) got about 20 mpg while running away from that stupid TT Stealth of my brother's. We basically set the cruise control at 200kph and left it there until St. Mary's.

Imo000

Next time when youfill up the gas tank try to put as much as possible in it, then record the amount of fuel you put in the tank. Then, record the amount of fuel you need to put int he tank the next time you are at the gas station. This will give your the total amount of fuel you've used. Use this volume and the recorded distance to determine the L/100 km rate.

Since we are talking about fuel efficiency, I can get 1200km on 61L of Diesel on my daily driver '00 TDI Jetta. That with 90% highway driving at ~130km/h.

G Man

When I drove the 84' back from FL I averaged 20mpg for the 3K miles trip. I kept track of the amount of gas I used and the miles traveled. It came out about the same if I did the calcs by the tank or for the entire trip.

ColinB

Malcolm
Something is wrong there. Get it checked out on a diagnostic machine. My figures correspond exactly with Garth's at about 10km/l (or 10l/100km) at 120-140kph. This was recorded on 95 octane fuel during a 1400 km trip and suggests, though I didn't prove it, that I could get about 800km out of a tank. Lately I've also come to believe in the accuracy of the trip computer which confirms these figures.

Colin. 89GT

oups59

Like Garth, I am doing around 10-11 Liters / 100Km at 120 Km/h on the highway. Much more in the city.

Drmark

On UK 98 octane my GTS averages 20 miles to the UK gallon (13.5 litres / 100 km) - less 10% (ie 18 miles per gallon) for short journeys and plus 10% (22 miles per gallon) for crusing at 85mph.
Those figures are based on 7000 miles this year.

Schocki

The gas tank has a capacity of 86 Liter. The best gas mileage that I ever got out of the car at constant 75 mph or 120 km/h was 10.5 l/100km (approx 22 MPG). Zeroed the computer on the highway and had the AC off, outside temperature was about 50 deg. F.

I average about 13 l/100km when I drive to work every day (highway and city).

If Nicole's friend drove on the highway and the gauges are accurate. I calibrated my tank gauge 4 months ago and it's now showing the correct fuel
The numbers are 100% correct and don't surprise me.

Bill Coleman

You guys are probably going to call me a liar, and I'm not sure I believe it myself - but when I first bought my 928 and drove it from just outside DC to somewhere outside Cleveland I got just under 30mpg. The rest of the trip home to Ann Arbor yielded the same results. Mind you I was probably driving about 65mph the whole way, with my wife and not quite 2 year old daughter following in her Honda Accord, but it still seems incredible. I've never been able to do it since - but I've never tried driving any distance at that kind of speed either!

the flyin' scotsman

Too much Garth


[/QUOTE] At a 125-140Kmph cruise, I find the S4 to yield a reliable 10l/100Km - quite impressive IMHO for a '80s 320 hp.[/QUOTE]

With this economy your getting over 800km from a tank of fuel which is double where I'm at. I fill the tank 'till it can't take more and run it 'till the idiot warning light comes on @ just over 400km. I doubt that I'm averaging more than 140kph although there are 'occaisions' when the car is going considerably quicker I think I've got a problem Huston.