First off, a disclaimer, there's nothing scientific about this. I'm merely sharing observations on the impact certain "mods" have on fuel economy.

Mileage is calculated the old-fashion way using only data from my daily commute. Track days and other tanks that involved aggressively spirited driving are not included. Almost all tanks are Exxon 93 (a couple here and there are Chevron or Shell 93)

21.47 - Avg MPG "stock" w/ 245/40/19s and lightweight 19's (26 tanks)
21.38 - Avg MPG after grounding kit (8 tanks)
21.96 - Avg MPG after Injen SRI (26 tanks)
20.76 - Avg MPG after moving up to 255/40's (16 tanks)
21.68 - Avg MPG Akebono + 2pc fronts (19 tanks)
21.05 - Avg MPG BC Racing (Insufficient/Irrelevant as of post date)

Sadly, i don't have full-stock numbers, the wheels went on almost immediately after i bought the car. Mods are cumulative, meaning each line down includes the mods immediately above it.

You can make your own conclusions. What i found was that the only significant change was when i moved up to slightly wider (heavier) tires, the impact of which was neutralized when the lighter Akebono calipers and lighter 2pc front rotors went on.

Overall, i may not have gained anything MPG-wise, but i surely haven't lost any either, plus the car feels better, and could very well be faster due to less unsprung weight.

 

props to you for having the discipline to track this data

 

I got a consistent 13.7 with mostly city driving with my vortech on 20's

 

stats cant lie, good observation and discipline to keep the data and thank you for sharing it with us.

 

Stats may not lie per se, but they can most certainly mislead.

Back on topic, thanks for sharing your results soundmike, always curious how different wheel setups, mods, etc., affect mileage.

 

i wonder if they are true results because of the different sized tires? and if a better intake would go further

 

I'm not sure what you're saying, the data is as true as it gets, within the scope of the mods.

 

different sized tires arent compensated in the calculations by the computer. thats all i was saying. and a better intake might show better results

 

These are calculated the old-fashioned way.

Better intake might show better results, these are just based on the Injen.