2007 Jeep Liberty Limited 4dr SUV 4WD (3.7L 6cyl 4A)
We too noticed right off the bat that the gas mileage was horrible: about 16 mpg average: we took our jeep to a great mechanic who laughed and said you need to understand that Chrysler uses crap parts: he started by lubing with amsoil synthetic, threw away crap spark plugs and installed Bosch Platinum +4's, nitrogen in the tires and now we average 25 mpg which is a great improvement. Dealership wanted $500.00 + to change spark plugs every 30k said would take 1 1/2 hour, they lied: mechanic showed me how easy it was, took 20 minutes and Bosch plugs are 100k mile plugs. Don't trust dealerships they steal your money.
with new good plugs, very quick, smooth acceleration curve, nimble, tight turning radius, great gas mileage.
Stop using crap parts that dealership will rob customers with.