997C4S (X51) Fuel Consumption

[nine11]

Can anybody advise on expected fuel consumption for 997 C4S (X51)? My calculations are nothing like any specification that I have read... it is definitely between 10 and 15 mpg. In one fill it was less than 10mpg for the tank. It is relatively new (800km). I have done individual tank fill calculations and totalised what has gone in (less start/end) vs kms. Every now and again it splutters, it is so abrupt and raw! I drive quite hard (fast) and enjoy accelerating in/out corners. Love the sound. Is the fuel consumption expected or will it get better? Any idea how long rear tyres should last if driven hard. I am getting worried about those too. After 800km the outside edges are looking considerably worn.

[PAULSPEED]

Hi,

I usally get about 18MPG with my stock 997S. On

the track I get about 6.1MPG and I have had it down

to 5.9MPG.

Trying to decide what is normal is very difficult with

these high horsepower cars.

Paul

[greerj1]

Remember that the mileage listed is compiled in near lab conditions to optimize the rating. With your driving habits and mine as well, expect 25-40 % less than advertised. It takes a lot more energy to accelerate a car to 100 mph than it does to keep it there. Take it to the track and get 5-7 mpg, you will feel a little better on the road.

J. Greer

[tomnash]

~18 is typical except on interstates where I can exceed 20-22.

Watch your rear tires carefully at around 10,000 miles or less. Check the *inside* wear as the camber is set up for racing and my tires, at least, wore unevenly after dominantly cross-country driving. Unless you have the car up on a lift it is hard to see the inside treads -- so reach your hand in and feel the treads!

[JeTexas]

It really depends on how hard you're driving it. These engines can get 25 mpg highway if you set the cruise control at 65 mph. In town with conservative driving in traffic, expect 18 mpg.

If you're constantly stomping the pedal, don't expect better than 12 mpg.

[leneuromancer]

From Jackson, MS to Dallas, TX (400mi) recently I averaged 71mph and got 26mpg (both according to the PCM)

It really depends on how hard you're driving it. These engines can get 25 mpg highway if you set the cruise control at 65 mph. In town with conservative driving in traffic, expect 18 mpg.

If you're constantly stomping the pedal, don't expect better than 12 mpg.

[nine11]

Thanks for the feedback. I initially calculated 6mpg but thought I must have got it wrong so didn't post it. I clearly have been bad.

[nine11]

Can anybody kindly advise on resetting the fuel consumption computer? I have Sports Chrono. The MasterTech pulled/pushed a lever on the column which reset it but I don't know what menu option he was in.

[sclemmons]

2006 C4S X51. Six speed. Approx 15 mpg in town. 25 on the highway at 76 MPH average speed. Could get more in town if I worked at it.

Reset the dash MPG by adjusting the lower left lever until the average MPG shows and then pull it straight back and hold until the reset occurs. Can do likewise with the average MPH as well.

Edited July 7, 2008 by sclemmons

[White987S]

Reset the dash MPG by adjusting the lower left lever until the average MPG shows and then pull it straight back and hold until the reset occurs. Can do likewise with the average MPH as well.

I think you mean to say pull it straight forward.

[White987S]

I drive quite hard (fast) and enjoy accelerating in/out corners. Love the sound. Is the fuel consumption expected or will it get better? Any idea how long rear tyres should last if driven hard. I am getting worried about those too. After 800km the outside edges are looking considerably worn.

Did you do a proper engine break in process?

[sclemmons]

I push the shifter forward into first, pull it back into second. Doesn't everybody? It sound odds to me to push back into first and pull forward into second. I pull the MPG reset in the same direction as second, "back", if that helps you.

Reset the dash MPG by adjusting the lower left lever until the average MPG shows and then pull it straight back and hold until the reset occurs. Can do likewise with the average MPH as well.

I think you mean to say pull it straight forward.

Edited July 13, 2008 by sclemmons