The results of my experiment are in...
Some notes before the numbers:
- I drove a combination of surburban/city/highway driving during this experiment, I estimate I did a similar amount of driving with both sport and regular mode...maybe a bit more highway with sport mode.
- Regarding driving style - I would say I drive faster than the average person, but I try not to rev the engine up excessively.
- The weather here got quite cold during the middle of my experiment (like -10ish as a high one day), but I think overall the temperature averages during both my sport and normal tank were pretty comparable.
- I reset MPG/trip meter before leaving the gas station after each fill up
- I never used the paddle shifters in sport, accept accidentally one time

- I never used eco mode
Driving exclusively in regular mode -
Miles driven: 281.3
Gas used (per pump): 14.93 gallons
Car reported avg MPG: 21.5
Calculated MPG: 18.8
Driving exclusively (or > 95% of the time ) in Sport mode -
Miles driven: 272.2
Gas used (per pump): 14.74 gallons
Car reported avg MPG: 21.1
Calculated MPG: 18.5
Verdict? Sport mode doesn't guzzle much extra gas. However, I think it gives you the opportunity to burn through more gas if you use the mode to accelerate aggressively, often.
Other thoughts:
- Like many others have found, the computer is reporting optimistic MPG numbers. Interestingly enough, the difference between the MPG from sport to normal for both my calculated and car reported was very similar. I wonder why the car calculation is off so much? Are my calculations missing something?
- I did get the fuel gauge software update, it seems to let me go through about 15 gallons exactly before it says it's empty. Still a lot of reserve
- The MPG is pretty crummy in cold weather. Oh well, I didn't buy this car to save money on gas