MPG's
I was getting 17.1 mpg in the city before I added my lightbar and basket, now I get 16.7 because of the increased wind resistance. On the highway I'm averaging 21.7 mpg, down from 22.4 mpg.
I haven't done any other exterior mods, or anything under the hood.
Check your air filters, spark plugs (Still using the stock NGK double platinum's at 60,000 miles, they're rated for 90,000 miles) and tire pressures (I run 33 psi).
Maybe your speedometer isn't calibrated correctly, which is causing your odometer to be off, making it look like it lowers you mpg's. This could be caused by a change in tire size, or by excessive wear. Remember some models came with 215/75/16 while others came with 235/70/16, if you bought your Jeep used, they could have changed sizes, or it could be an error from the factory. That's a 0.9% difference, which could account for some of lost mpg's. Compare your odometer to someone else's over the same trip and see if they're the same.
Pay attention to your driving habits. The harder you accelerate, the worse your fuel economy. If you see the light turning red up ahead, let off the gas and coast in to it. Try to pick a route that avoids long idles at stops. (I live in a relatively small city 60,000 where traffic isn't too bad, and the lights aren't long). I don't drive like a grandma, but I don't drive like a maniac either. Smooth acceleration and smooth stops, 5 mph over the speed limit (never more, never less).
I don't know why my mileage has always been better than what's reported here, but I'm not complaining.
