3.7L mileage

NewOldTimer · **Posted:** Wed Dec 22, 2010 7:09 pm

Apologies if this has been discussed previously, but here goes.

Just picked up a 2004 Liberty back in October with just over 37K miles.
My only concern thus far is my gas mileage.
Everything I've read tells me I should be getting around 15-16mpg in town.
My best tank to date netted 14.3mpg, with my average to date is about 13.5mpg.

Is this normal for "city" driving?

I'm only concerned because my previous vehicle was a full size pickup
with a big V-8, and I got 12-13mpg with it. My Liberty is a V-6 & weighs about 2000
pounds less.

I've been looking at the "performance chips" available.
Does anyone have any experience with these??

There are 3 contenders I'm looking at; SLR, GForce, & Jet.

Do they require at least 89 octane, or can I run "regular" gas??

Any thoughts or suggestions??

JeepinJarhead03 · **Posted:** Wed Dec 22, 2010 7:18 pm

Ton of mileage discussion here

viewforum.php?f=51

for the most part, yeah your mileage is about right

many variables to "bad" gas mileage, newness of spark plugs, cleanliness of airfilter, properly inflated tires, outside ambient air temperature and the ethanol % content of the fuel

Jeepjeepster · **Posted:** Wed Dec 22, 2010 8:38 pm

Thats pretty typical for stop and go driving. My 3.7 seems to get its best around 55-60mph(~19-20) on country roads. Any speeds higher than that it starts dropping pretty fast. Most of my driving so far has been on interstates with speed limits of 70mph. She gets around 17-18 with cruise set on 75mph with some rolling hills. Mine averages about 15mpg in the city but Im pretty easier on her.

Clean air filter, new spark plugs, and good tire pressures are some places to start. Youre driving an under powered 2ton brick, so dont expect much. Your truck may of had a V-8 but it didnt have to work as hard to pull that truck around as the v-6 in the kj does. Our Hemi Grand Cherokee gets the same mpg as my liberty and it probably has more hp and torque than your truck did.

DirtyKK · **Posted:** Wed Dec 22, 2010 9:07 pm

the "performance" chips are all junk and wont help mileage. fresh/clean fluids throughout. clean filters and sensors. lose any excess weight in the jeep and run proper psi on highway tires. some of these will keep your mpg's or maybe give you a couple back depending on conditions.

LibertyFever · **Posted:** Wed Dec 22, 2010 9:53 pm

Unfortunately the gas mileage of a Liberty can't be improved very much. Do bother spending money on chips or fancy voodoo devices that promise to improve gas mileage.

Use common sense, it won't cost you very much. As suggested do a tune up, change the fluids, filters plugs and maybe plug wires & distributor caps, check the tire pressures and empty your Jeep of extra weight.

Oh, and FYI: I get about 22 MPG highway on my Libby.

tommudd · **Posted:** Thu Dec 23, 2010 12:20 am

LibertyFever wrote:

As suggested do a tune up, change the fluids, filters plugs and maybe plug wires & distributor caps, check the tire pressures and empty your Jeep of extra weight.

Oh, and FYI: I get about 22 MPG highway on my Libby.

I have yet to change the plug wires and distributor cap on mine and I have 150,000 miles :shock:

Should I do that ? :goink:

Just kidding ya since I know that you didn't mean that :wink:

But as suggested since you bought it used I would go through and change out the plugs ( Autolite) /air filter to a good stock or Amsoil one, change diff / transfer case and trans fluid and you should be good to go. If those haven't been done for a while it may help a little bit. Colder temps mess with the mileage as well.
Hauling too much weight will cause less mileage but I haul way too much , have heavier skids, rock rails etc and can still average 21 easy enough at 70-75

Albert · **Posted:** Thu Dec 23, 2010 1:59 pm

LibertyFever wrote:

Unfortunately the gas mileage of a Liberty can't be improved very much. Do bother spending money on chips or fancy voodoo devices that promise to improve gas mileage.

Use common sense, it won't cost you very much. As suggested do a tune up, change the fluids, filters plugs and maybe plug wires & distributor caps, check the tire pressures and empty your Jeep of extra weight.

Oh, and FYI: I get about 22 MPG highway on my Libby.

So that's why my gas mileage stinks....someone must have stole my distributer cap and plug wires........cause they ain't there no more... :ROTFL:

Just teasing..............had to do it........ :mrgreen:

SETexasLibby · **Posted:** Thu Dec 23, 2010 8:32 pm

Albert wrote:

LibertyFever wrote:

Unfortunately the gas mileage of a Liberty can't be improved very much. Do bother spending money on chips or fancy voodoo devices that promise to improve gas mileage.

Use common sense, it won't cost you very much. As suggested do a tune up, change the fluids, filters plugs and maybe plug wires & distributor caps, check the tire pressures and empty your Jeep of extra weight.

Oh, and FYI: I get about 22 MPG highway on my Libby.

So that's why my gas mileage stinks....someone must have stole my distributer cap and plug wires........cause they ain't there no more... :ROTFL:

Just teasing..............had to do it........ :mrgreen:

AHAHAHAHA

EAGLE01_2002Libby · **Posted:** Thu Dec 23, 2010 8:41 pm

I do about half highway and half city.
I have 175,000 on my 3.7L
Air intake and exhaust
I get 13-14 MPG

KJ_WHEELER_2010 · **Posted:** Tue Dec 28, 2010 7:34 pm

darn lol I got like 22mpg on the highway before the lift and tires. I didnt get the chance to see what it was with the lift and tires alone.....but I know lift/tires and pulling a 4'x8' Uhaul trailer, both vehicles loaded down I was getting 13mpg. That was a slow trip I had to work to reach 70mph :ROTFL:

3.7L mileage

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