Quote:
My dad owned a 1981 vw rabbit diesel. It was a 1.6 liter NA diesel. Had no power but would get 60 mpgs all the time.
If you were to ever get your jeep into a range similar to a Rabbit (or even a Jetta), you wouldn't be at all happy with it's performance. After all, isn't there a reason you're driving a 4x4 Jeep SUV over a VW? The curb weight of your Liberty is 1000 lbs more than a Golf. (current equivalent of a Rabbit) Also, Jeep has made the decision to not use locking hubs, so even when you are in 2wd you are still turning the axles, diff, prop shaft and transfer case.
I suppose you could strip weight from your Liberty to improve mileage. Remove the back seats, the axle shafts, front diff, front prop shaft. Hunt down a fiberglass or carbon fiber hood. Change to the narrowest and hardest tires you can find. Remove the spare and it's mount....
I have a 90 mile (round trip) commute. All of which is Interstate except for about 10 miles. I run 75mph to keep up with traffic. In a year and a half my averages with a stock CRD have been 21-22 on winter fuel and 23-24 on summer fuel. It improves a little with 20% Bio, but it's out of my way to get it and I won't run Bio in the winter. Bio also makes all of my diesels run quieter.
Some things that I did right after I bought the Liberty (with 145k miles) was replace the alternator decoupler, installed new u-joints, and new CVs on the front propshaft. All needed repair and all three made incremental improvements. Good maintenance makes a difference, even little things like air filter, tire pressure and a good coat of wax.
Another way to save money is to simply slow down. I take regular road trips and when I get off the Interstate and drive state roads my fuel economy jumps to 27-28, just by keeping my speed around 60.
I now have 25,000 miles of experience with my Jeep. It gets better fuel economy than my S10 (similar weight and capability). My gas 4.3l only gets 16-17, and drops to 12 with my little trailer. The jeep tows better and only loses a couple MPG with the loaded trailer.
BTW, I traded a Jetta that got in the mid 30s for my Liberty. I called my Jetta the 'clown car' because it was so small. The Jeep is much more enjoyable to drive on a daily basis.