Taking a look at our ’05 Jeep Liberty's mileage log, we've saved at least $466 (at $3.69 a gallon), and as much as $500 (at the current $3.95 a gallon) over the last 7 months...

 Thanks to Green Diesel Engineering's Eco tune, the mighty little Jeep is earning its keep.

 Here's the breakdown: In the first 14,966.3 miles (when the Jeep was 100% stock) it guzzled 680 gallons of fuel, which comes to 22 mpg. Now, in the last 14,802.9 miles (with the Eco tune uploaded) it's used 554 gallons of fuel, bringing the overall average up to 26.7 mpg.

 Over the last two months the average mpg has dropped due to the onset of winter weather (and fuel). Prior to the cool down, we saw our overall average at 28 mpg for the longest time.

 Looking ahead, we should save roughly $360 more (over the stock tuning) by the 12-month mark. Of course, that's taking into consideration the fact that fuel prices will likely not come back down and with the winter weather hampering our efficiency a bit. Still, we'll probably continue to see 25 to 26.5 mpg.