Topic: Gas Mileage Thread

[jeepheap]

yeah... i'm serious. i checked it going out to bath ny and double checked on my way from bath to lake george. i thought it was incredible myself, that's why i did the math twice.

i didnt have 5th but it's not like i would have used it anyways, with all the weight. i even had to downshift to third most of the time on hills. i was following my brother in law in the minivan (maybe i was drafting?..) and he had it set at 60 the whole way. can't wait to see what i'm getting with out the trailer.

[SDWE61988]

I just read through this thread and I guess I am doing pretty good with my jeep.  I got her almost three years ago, and was averaging 13-15 mpg.  I have done everything I can think of and now I am averaging 17-19 mpg.  The Jeep has 206500 miles on her.  I have a 95 2.5l MPFI with 5 spd, 31 inch tires with a stock rear end.  I changed the speedo gear last year after I got a speeding ticket, believe it or not (Ironically I was trying to build up a enough speed to make it up the next hill!).  I also Added the trottle body spacer, cleaned the injectors, used seafoam, tune up (twice), and a couple of air filters.
I can maintian @ 65-70 mph in the highway (flat areas) and still achieve this, along with easy starts.  I start hard or run anything over 70, the mileage drops like a rock.

[chardrc]

i didn't have 5th but it's not like i would have used it anyways, with all the weight. i even had to downshift to third most of the time on hills. i was following my brother in law in the minivan (maybe i was drafting?..) and he had it set at 60 the whole way. can't wait to see what i'm getting with out the trailer.

a drafting helps allot with my jeep. there i a hilly highway be me and if i have a person to draft with i can go 60- but if i loose my draft Im struggling to keep 45 on the hills. and these hills aren't all that step just last forever.

[Jeffy]

yeah... i'm serious. i checked it going out to bath ny and double checked on my way from bath to lake george. i thought it was incredible myself, that's why i did the math twice.

i didnt have 5th but it's not like i would have used it anyways, with all the weight. i even had to downshift to third most of the time on hills. i was following my brother in law in the minivan (maybe i was drafting?..) and he had it set at 60 the whole way. can't wait to see what i'm getting with out the trailer.

I think the reason was that you were going 60mph.  When you start pushing it to 65 and higher your gas mileage will tank.  Also, were there many hills?  What's the weight of the trailer?  Drafting probably also helped.  I used to draft big rigs.  You don't have to get really close to them to get into the draft.  You can actually hear it get quieter.  It's usually around a car length behind the trailer.

[jeepheap]

yeah there were hills. anybody been up 81? it's alot of hills. and the trailer weighed in at about 350.

[jfrabat]

I think the reason was that you were going 60mph.  When you start pushing it to 65 and higher your gas mileage will tank.  Also, were there many hills?  What's the weight of the trailer?  Drafting probably also helped.  I used to draft big rigs.  You don't have to get really close to them to get into the draft.  You can actually hear it get quieter.  It's usually around a car length behind the trailer.

I agree with this; I tested this when i went to the Florida Keys last weekend, and I just drifted behind the RV's heading down and back up, and not only was my engine workload SIGNIFICANTLY lowered, but the gas mileage increased significantly.  By the way, I also shut down the e-fan during the highway run...  Which means I almost overheated when I got to the Keys because I forgot to turn it back to auto, but that's a WHOLE OTHER STORY!   

Felipe

[dexetr30]

yeah there were hills. anybody been up 81? it's alot of hills. and the trailer weighed in at about 350.

I live in northeast PA and I travel 81 heavily. I have never gotten that kind of mileage. I'm only running 235's with no lift currently and I'm lucky to get 15 mph. When we were in Maryland/Delaware a few weeks ago where it's flat we were getting around 19 mpg.

[st.chevrolet]

I have a 94 YJ 2.5L, 5 speed, 4.10s, and 235/75 R 15 that when I 1st bought it got about 17-18 mpg in town, it was bone stock other than a little bit of a bigger tire. The few upgrade/tune-ups I have done so far have brought my mileage up to 21+ mpg in town.
The upgrades/tune ups include:
New NGK plugs
New fuel filter
MSD 8.5mm Super Conductor Spark Plug Wires
Home made intake with K&N filter
Electric two speed cooling fan
4.0L throttle body
Molyslip Oil Supplement (molybdenum disulfide oil additive)
  With these few mods I have gotten as high as 24mpg but most of the time it gets about 21mpg.

 I am in the process of turbo charging my 2.5L, and from what I have read after turbo charging I should see increases of somewhere between 4-5 mpg. This information comes from others who have done the same procedure to there 2.5L. Needles to say a gain of 4-5 mpg is great but while also making the same or better HP power & torque of the 4.0L   

[swatsniper1s1k]

91 YJ, 2.5L. 5spd, 4.10s street tires dimension of am. racing wheel is 15x10 tires are street prolly 27 or 28 inches. Only engine upgrades are new spark plugs, 8.5mm super conductors, high voltage coil, new distributer cap, and Flowmaster series 40 muffler. with that all, i'm pushing 26 miles a gallon highway, cruisin about 5mph under speed limit cuz my squirrels cant run fast enough, and some extreme hills. I am trying to decide whether to drop the money into a turbo, supercharger, or inline 6. trying to get the most power possible without jeopardizing vehicle balance with a chevy small block 305. anybody have any knowledge as to what works best?

[brian674]

OK, I got 22 MPG and 23 MPG, all highway with an average speed of 70 MPH. This was 3 weeks ago.

I get about 18 MPG in my normal everyday driving, which is mix of town and highway everyday.

2003 TJ SE
I have a stock 2.4L
I think it is a NVG3550 tranny, but not sure

A NP231/NVG231 T-case
D30/D35 axles with 4:10 gears.

[brian674]

Forgot to specify tire size (215-75-R15 Goodyear Wranglers)

[Jeffy]

I think it is a NVG3550 tranny, but not sure

If it's stock it has an NV1500.

[jrollings]

94' yj
2.5l
130,000
15 mpg
4" suspension lift
33" mud rovers
3.73 stock gears: will be going to 4.56s soon as well as upgrading to super 35 kit and 4340 alloy front axles
high flow intake

needs new air filter and tune up and exhaust leak fixed 

[BarneyJeep]

'98 TJ
2.5l (140k miles)
ax-5
30/35 w/ 4.10's and open
34" LTB's on 15x8 black steelies
mainly 4th gear try to keep the motor around 3k RPM
avg 15-16 MPG on 87 oct

[BarneyJeep]

edit: 4.0l intake tube with open "ricer" filter
       Super Turbo muffler with stock cat + tailpipe