Maxing fuel economy.

[LibertyMan02]

So I got my Liberty as a commuter and I'm wanting to squeeze as much MPG as I can on it. Since the muffler is rusted out, Putting a flow master on there should help. Next would be a new air intake. I've been looking at the K&N, but I've noticed that the only one they have for the 02-03 jeeps is one that hooks up to the resonator. The ones for the 04 and up delete the resonator and go right to the throttle body. Is there a big enough difference in the 02 V6 verses the 04 and up V6 that the later intake wouldn't work on my 02? Just wonder if it even matters if the resonator is on or off. Last that I've found is a throttle body spacer. anybody have some insight on other mods to improve MPG?

 

[CzarKJ]

Stock airbox will get you as much MPG as you are going to get. Throttle body spacers are snake oil (in my opinion) with computerized engines. The exhaust might help slightly but the most you can really do with a stock setup is to maintain your tire pressures and get the lead out of your foot. This isn't really a great MPG vehicle and wasn't designed to be.

 

[tommudd]

K&N is not going to do anything but suck extra dirt, Flowmaster will make noise is about it, maybe a very tiny amount but not much

 

[ltd02]

Best thing I ever did was go back to the OEM copper plugs. That and keep up on the regular maintenance like oil changes. Stock air box is engineered to be efficient. If you really want a complete intake look at AEM. I have a brute force intake on my 02 but all it does is make the neat sucky noise. I call it the HAI. Don't think it helps MPGs at all.

 

[LibertyMan02]

Well, I'll be honest, after driving my burned out 86 ford diesel and getting avg 8 MPG, anything is an improvement. LOL. So y'all are saying the spacer plate is not any good? Excuse the ignorance. I've been my own mechanic and did all the work myself. I know the diesel beasts like the back of my hand, but this fuel injected, computer controlled gas stuff is over my head. Gotta learn somehow. I have no faith in the clowns at the dealer.

 

[ltd02]

The spacers don't work. What are your MPGs now? My 02 is getting about 18mpg at 60/40 city/highway.

 

[LibertyMan02]

Don't know yet. Got a nearly full tank of gas when I bought it. it was a city driver. It wasn't being driven that much according to the PO and the lieometer dove down to 9 by the time I got it home. Reset it and after 3-4 trips of my driving style, it's up to 15.5. I'll reset it again at next fill up, since I've fixed the leaking quick connect fuel line fitting at the tank.

 

[ltd02]

I have the computer gizmo too but I like to calculate my mpgs. I never believe those things. How many miles? Unless the PO gave you service records, I'd check/change the plugs ASAP and do all the fluids. May help but sure can't hurt.

 

[LibertyMan02]

130,000. Gonna have to wait two tanks to get a MPG. Is plugs hard to change? I've heard horror stories of plugs becoming harder to change on some newer gassers.

 

[ltd02]

Just did mine a couple month ago. They are deep in there but took less than 30 minutes. Aluminum heads so make sure you use anti-seize and torque them to spec.

 

[LibertyTC]

I use stock air box with clean filter & change my plugs using copper core / NGk's as listed on the under the hood sticker.
Best to do them every 20-25K miles. I have noticed the fuel economy really drop off as the plugs /gaps wear. So keep em fresh & keep KJ happy! I am lifted with all the skids etc & I am lucky to see 15mpg on the hwy. Also I have noticed that on hwy runs, adding some Chevron Techron Concentrate plus fuel/ injector cleaner has got me a bit better fuel mileage.
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Here is a good video that show how 2 change "All" the plugs LOL!!
How To CHANGE SPARK PLUGS 02-07 Jeep Liberty 3.7L - YouTube

 

[CzarKJ]

Also giving your throttle body a good cleaning will help a little as well!

 

[profdlp]

With the plugs, to get at the rear ones I found it a good idea to use two short socket extenders. Get one in there with the plug, then attach the other one and crank away. It's easier than trying to angle one long extender in there.

 

[LibertyMan02]

Ok. Thanks a bunch. Sounds like the same thing I deal with on the glow plugs on my diesel. My plan was to put some AT tires on it and leave it stock lift. May need to battle mountain snow In the future.

 

[tommudd]

Plus take it out and run it good a few times a week, blow that carbon and crap out. Doesn't hurt them one bit, don't drive like some of these people who try and get 100 MPGs .
Mine hits 5000 or so RPM every day I drive, has since new and gets 21-22 on the highway with a lot of dead weight ( me and bumpers etc :icon_lol
Plugs ,.... Champion coppers work great as well

 

[LibertyTC]

X2 as above..Burn off the carbon!
Once I had the two bottles of Chevron Concentrate in the Jeep tank there was a clear highway with a long steep hill.
Put my gas pedal to the floor! 5000 rpm was definitely accomplished.
Ah..there was some black crap noticed exiting the tail pipe!
I think Jeep does like this treatment, cause once I got back after the 200 mile boogie, the idle was smooth and even a bit lower!
I now add the concentrate every 3 months and drive it... more like prepare for take off LOL.. a while on the hwy.
City driving and extended idling without blowing the dust out is not good long term.

 

[profdlp]

Once school was done for me (30 highway miles 3-4 times a week) I didn't always have a need to get on any road above a 45mph speed limit. It took no time at all for me to notice a difference in performance. Like 'TC and Mudd, I now make it a point to get some 65mph* high-rev time on a regular basis. I think my Jeep feels the same way about that as I do after a really good workout.

*65mph being the speed limit, not what I actually drive.

 

[LibertyMan02]

Ok, I think I'll put my money towards some seat covers and some tires. That leads me to the next question. I'm wanting to put some AT tires on the Jeep, but am wondering which one would give the best mileage. Most of my family want with the BF All Terrains.

 

[ltd02]

I sort of like the Firestone Destination ATs I have on my 4 liter 98 Ranger. Probably not the best for even moderate off roading but ride nice and pretty quiet. I get about 19-20 mpgs 60/40 city/highway. Of course that may change since I'm heading out to the garage right now to convert the POS PVH hubs. I'm about to lock the front hubs for good until I can get some manual hubs. They were never reliable and I want 4WD when I need it.

BTW ordered my Dest ATs from Tirerack

 

[LibertyMan02]

Ok. Appreciate the help. I'm searching the forums and am getting mixed results. I may have to relocate to the mountains and will have to deal with snow, as well as possibly trying my hand at some of the mountain trails. Just want something that will fit stock rims and no lift and still give me good results on the highway, yet won't get stuck in the mud or snow.