Howdy from Texas y'all, Jeep Liberty Renegade
 

Hey I'm EcoRenegade from the North Texas area. I purchased a 2005 libby reny back in 2009 with 35k on the dial. It now has 116k and counting. My goals are to increase gas mileage to 40+mpg without compromising the functionality of the Jeep. I like the trails but most of my time is spent on highway road trips. Looking forward to the journey and all of the comments.

Welcome. I wish you well but i think you're going to have a tough time getting much more than 30 on a tank average. What are your plans so far?

I hope you have a manual transmission. I had a diesel with the 5 speed auto, and even with the extra efficiency of the diesel, 30mpg at 60mph was the best I ever got.

There is a lot you can to to improve the aerodynamics. Remove the roof rack, install smaller or remove the huge ears (mirrors), grille block, air dam, belly pans, lower the ride height. If I recall, a fellow on lostjeeps.com was getting mid 30s from his CRD with some of those mods. He also installed a bunch of air tabs, but I doubt those helped.

Welcome to the site.

As the others have said, 40 mpg is going to be a pretty big stretch. But, I'm anxious to see what you can get out of it.

Thank you all for the warm welcome. Tough.. yes. This is my style. I usually go for the projects that most people would say are impossible. My plans are to try the "common" mods first, but I'm trying 3-4 different designs of each and measuring the differences. I'll post the complete list in my profile... it's a ton.

Any and all tips and help are welcome and will be attempted. I am willing to do things to my Jeep that most Jeep owners laugh at.

Ok, so I'll post it here and make a new thread later.

Phase 1
Cleaning our the radiator and other ongoing maintenance
Suspension lowered 1" all the way around - done
Grill mesh and block - in progress
Wheel covers, flat
Deleting roof and rock rails
Changing door handles to flush mount versions
Deleting extra weight where I can
Panel gap fill...Tron style

Phase 2
Air dam/skid plates
Undercarriage plates
Throttle body spacer
Cold air snorkel intake
Moving radio antennae to back
Rear wheel well covers

Phase 3
Custom fibreglass 5" cowl hood
Gas tank pressure/vaporizing system
Removing bulky offroad lights and replacing them with LED versions that follow the body lines.

Let's tot up the anchors holding you back:

Two tons of weight

4x4

Bungalow profile

Jeep

And finally, automatic.

Holy cow. Well, I'll give you this: you're ambitious. There's precious few here that have ever achieved multiples of their EPA average, but if you have it in you I think you should get, I dunno, a tattoo or maybe a certificate from the director of the EPA. Or maybe the director give you the tattoo.

I think the cold air snorkel intake is a big no-no. For better fuel economy the generally accepted wisdom is a warm air intake. Plus of course it'll just present that much more resistance to the wind, also not helpful.

This should prove interesting. I look forward to seeing how it develops.

EcoRenegade, you should probably edit your fill-up in your fuel log. The entry shows that you paid $38.60/gallon. :eek: I can't believe gasoline is that expensive in Texas.
Welcome aboard!
I agree with elhigh; your quest for 40 MPG highway is extremely ambitious, and possibly even slightly unrealistic.

Ok y'all.. Let's not start a war here, Texans are good at that. I happy to see there some feedback for me to try. Warm air vs cold air etc..etc.. If someone doesn't at least try then nobody will ever know. I can't sit here and let Jeeps get deleted from Eco mod space for no reason.

I will start a thread in the DIY area soon on this. I want lots of data to post for this forum to give back to the help I've gotten. Yes, it sounds crazy. I laughed too when the idea first entered my head.

Since 2014 I have taped and card boarded prototypes all over my Liberty and measured the differences. I am hoping that sharing my work and photos here will turn out an idea I have not thought of yet. It's has been a small mod here and there. Now, I am ready for some serious alterations.

Saddle up and let's ride. :)

Whatever you do, please do NOT take the notion that I think you're stupid or crazy.

I would dearly love to own a Wrangler - I love driving my mom's - but the lousy mileage holds me back, even an older, lighter model with the 2.5. If you can wrestle decent numbers out of a Liberty without it looking too over-the-top, I might be able to convince the wife, who would also like a Wrangler, and also stays away for the same reasons.

When you say "taped and cardboarded prototypes," that makes me think you're going to go all Basjoos all over your Libby. THAT would be something to see, 4x4 high-steppin' full boattail heading down the road. It would make a strange confluence of paradigms.

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.

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

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. :thumbup:

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?


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

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.

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.

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.


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 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

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..

It might have some relation with the fuelling system used in the vehicles.