Am I the only one not hitting the mark

[popimp]

Am I the only one that's not meeting or exceeding the EPA? I've scanned a few vehicles in the Garage and everyone is at least %10 above the EPA ratings. Me on the other hand I'm 3.5% below. Granted my drive to work is only 4 miles long, so this could be a huge factor I think. I pumped up my tires from 36 to 40 and installed the scan gauge. According to the Scan Gauge I'm currently averaging 19mpg. I've been using the gauges, coasting with engine on, and turning off the vehicle at stop lights. Hopefully my future mods will bring me to at least 25mpg.