Howdy from Texas y'all, Jeep Liberty Renegade

[spacemanspif]

I smell a removable, hitch mounted boat tail in your future. Or maybe a trailer like BamZipPow made. You do have a hitch, right? Dodge gave everyone one for free because those cars go up in flames quick in a rear end collision due to the exposed gas tank when not equipped with a hitch.

For the time being, leave the roof lights where they are but boat tail the rear of the housing. The frontal area is a MPG penalty but the rear isn't helping either and can be addressed with some tape and plastic relatively easier than the delete/remodel in your long term plans.

[BabyDiesel]

Every time I come back to this thread, I'm reminded of DieselDave and his epic 57.42 mpg tank in a Cummins powered Dodge Ram, which shows that the seemingly impossible can surely be accomplished.

OP, check this thread out if you have not! -> http://ecomodder.com/forum/showthrea...5-a-26259.html

[Mustang Dave]

One thing to consider is an underdrive pulley or underdrive pulley set. It won't make a dramatic difference in fuel economy, but it will make a measurable difference.
I installed an underdrive crankshaft pulley on my Mustang this past May. It gave me about 1 MPG (about 3%). Break-even will take about 80K miles, but bragging rights are immediate.

[cRiPpLe_rOoStEr]

Maybe it's not impossible to get 40MPG on highway, but would still be more likely with some engine mods. BTW which engine is fitted to your ride?

Originally Posted by EcoRenegade

Moving radio antennae to back

Which kind of radio are you talking about? CB radio?

[elhigh]

He's got the 3.7 V6 aboard. EPA rating 15/20/17 combined with the 4-spd auto.

Do everything. Everything you can: behavior mods, aero mods, engine mods.

[EcoRenegade]

Originally Posted by elhigh

He's got the 3.7 V6 aboard. EPA rating 15/20/17 combined with the 4-spd auto.

Do everything. Everything you can: behavior mods, aero mods, engine mods.

Thank you elhigh for answering the engine question for me. I've been catching up on vehicle maintenance and creating metrics to measure these mods with. Be back soon with a good data set.

My Jeep has a 3.7L, auto, 4x4, and towing package.

[BabyDiesel]

I would look into custom engine tuning. To get to 40 mpg, you will want lean burn and optimal efficiency across the board. This one of the ways I am going to use to reach 75 mpg in my car.

Look into one that you can data log yourself and adjust parameters, if one exist. Idk if many suppliers offer much for a 100% focus on mpg. There will be a learning curve, but you have the luxury of doing whatever you want.

How do you feel about emissions? Running lean will increase your NOX output, and idk how you feel about making emissions worse.

[cRiPpLe_rOoStEr]

Originally Posted by BabyDiesel

I would look into custom engine tuning.

So would I. Apart from the EFI tuning, there are other pathways that can do little miracles to fuel-efficiency, such as valve timing, intake and exhaust flows, and even forced induction can help in certain situations.

How do you feel about emissions? Running lean will increase your NOX output, and idk how you feel about making emissions worse.

That's a good excuse for experiences with gaseous fuels such as propane and CNG, as they tend to decrease the intake temperature, thus NOx levels are also likely to go down.

[ksa8907]

I believe you have the 42rle transmission. Im not familiar with that particular one but here is a link to information about a nearly identical 42le. Gear Swap Question, Experience Needed - DodgeIntrepid.Net Forums - Dodge Intrepid, Concorde, 300m and Eagle Vision chat

[crashnzuk]

Originally Posted by cRiPpLe_rOoStEr

That's a good excuse for experiences with gaseous fuels such as propane and CNG, as they tend to decrease the intake temperature, thus NOx levels are also likely to go down.

I don't know about propane, but in my experience with CNG, the NOx is very high. We used to have quite a few CNG vehicles at work from factory build Dodges to retrofit Fords. One thing they all shared come smog check was NOx right at the ragged edge of failure.
Travis..