23mpg highway on a 1997 ZJ 4.0L? That's great given the EPA rating of 20 highway....
I haven't taken the '05 WK out on a long trip yet, but on my particular commute -- a 13-mile mixture of highway/city -- I can easily stay in the 17mpg range, where on the 1997 4.0L GCL I would be in the 16 range. An extra MPG in the winter when I don't have to use the AC.
Of course the five-speed automatic sure helps. And the 4.7L was a brand new design in 1999, as well, and has a lot of features to enhance fuel economy along with more sophisticated engine management to help compensate for the larger displacement.
Cape Canaveral, Florida
2005 Jeep Grand Cherokee Laredo 4.7L
2005 Dodge Durango SLT 4.7L
I had a 1999 Grand with the QuadraDrive and I was actually getting around 19-20 MPG on the highway if I was steady driving it. I realize this thread has been going for a while and my "two cents" may be too late, but I can tell you that there are two things that helped my mileage. First, was a K&N Cold Air Intake. The second was a breakdown and thorough cleaning of the throttle body. Very easy to do and it was badly needed. Didn't really think about it and did it at about 130K miles. Made a huge difference in idle smoothness and I think that combined with the intake made a difference in my mileage. Also, I have tires that are a little larger than stock, but not by much, they rub a little on the splash shields in the front...only mentioning it because I was still getting pretty good mileage for a Jeep with that many miles on it. Now I have a Hemi and I miss that mileage.... :-(
i have an 06 grand cherokee with the 4.7 and i have about 21000 miles on it. my average mpg on the evic is between 17.5 and 17.8. i calculate out the per tank miles per gallon almost every time i fill up. generally my 10 mile commute to work every day i get about 16. i make frequent trips up to waterloo ny which is 3.5 hours of highway driving and i get somwhere around 19.
2006 Jeep Grand Cherokee Larado 4.7
I'm not sure a 6 banger will get you better gas mileage becasue the commander is very heavy, several things you can do to increase mileage is get rid of the stock air intake and go aftermarket, a throttle body spacer and a less restrictive exhaust. These are just a few things and there are several others, but if you are worired about gas mileage a hemi should not be your sights as the best you will see is around 21 mpg on the freeway and to get that you will have close to $800-1000 in mods, and will take awhile to auctually pay for themselves (years not months)
I read somewhere that if the engine is direct into the cyclinder fuel injection that a throttle body spacer has no effect on gas milage. Do not know if it is true but think about it, throttle body has no effect on fuel vaporization if the fuel is injected directly into the cyclinders.
Previous Jeeps: 84 CJ7 (A True Jeep), 2000 XJ (163,000 Miles/Totaled (Pictures of wrecked Jeep in gallery)), 2004 WJ (parting out die to major electrical issues)
If you don't have time to do it right the first time, how do you have time to do it over.