I have a AMC 360 in my YJ. This is the forth jeep its been in. I got when I bought a 78 CJ5 that someone had transplanted it into. I swapped it into a 84 CJ and now the YJ. I got 13 mpg in both CJ's with maual trans and I get about 11 mpg in the YJ with a automatic trans. I don't baby it when I want to go I go. If I wanted economy I would buy a Yugo.

I get about 13 on avg. & I also run 31's.

It appears that "most" people running the 2.5 or the 4.0 are getting between 15 and 20 MPG with no or only minor mods. So, if you find yourself on the tails of this curve, you have to wonder what is wrong. I've seen a few good suggestions, including clogged cat, no cat, crappy filters, old fluids, low tire pressure, hard driving, front hubs remaining engaged in 2WD, and intake issues. There's also the issue here in the NE of the winter blend fueld, which will often result in lower MPG. The factory sticker on mine had an EPA rating of 15/19. So, the reported mode of 15-20 seems right on target.

90 islander 4.2 and i get around 20 depending how are were i drive. but when i try its around 20, so i would say plugs wires all the fun stuff. and get a cat it will help a lot u probably don't have enough back pressure.

Well all I know is I get no where near 15. Mine is somewhere between 8-10 and I never drive over 65 and usually take my time.

im not telling what i get. i might get the bs meter going on me. but get a gsp power spacer , it does wonders. tell them Randy from jeepers paradise sent you.

still getting 17mpg. trying to get it lower but it just won't drop

91 YJ, 4.0 running 33's, never got better than 12mpg..... I'm hoping for better with the SBC

Still waiting to get this stuff done.

Can you giveus more infor on how well the gsp power spacer works ?

my 94' (113,000 miles) with 33's,electric fan,4.0 throttlebody,cold air intake,high flow cat,2.5 inch exhaust get's about 12-14 mpg.
Alot of hills here in VT to climb.
I am just about had enough of the 2.5 though,gutless.

93 with 33 x 12.50 getting 9 and with stock tires about 13 and also so bad with the 33s its a 4 banger and so i hold the gears and let the motor screem to get her moving with traffic hahaha

ok here it goes,..................95 with a 4.7 stroker(for all you newbees...thats a 4.0 with a 258 crank) ive got 35x12.5x15s on 15x10s 4.88 gears ,borla exaust, doug thorley header.215 hp and i get over 20 with the gsp

I did a little research on this, did you get the optimal results when you installed it? It seems like a good investment for a 1-3 MPG increase for less than a 100 bucks. It would take many fill ups to pay for it's self would it?

I dont want to know what my jeeps get,,*LOL*