Older jeep mpg's

BobA · 05-25-2008, 02:27 PM

With gas prices climbing I can hardly afford to drive my TJ at 15mpg.I was wondering what kind of mileage I'd be looking to get if I got an older 4cyl cj or willy's.Which would remain close to stock.

**mnCJ7guy** · 05-25-2008, 05:21 PM

My 1980 CJ7 with a 151 4 cyl gets somewhere between 16 and 19 mpg.

cjwillie · 05-26-2008, 12:03 AM

my '83 CJ5, with a 258, 4 speed, and .273 gears (that i was going to swap out but never got around to) gets 25 or 26 mpg. till the gas prices come down, i like them tall gears.

xxxflhrci · 05-26-2008, 04:20 AM

Quote:

Originally Posted by cjwillie

my '83 CJ5, with a 258, 4 speed, and .273 gears (that i was going to swap out but never got around to) gets 25 or 26 mpg. till the gas prices come down, i like them tall gears.

Your calculator is broken.

BobA · 05-26-2008, 07:59 AM

Quote:

Originally Posted by cjwillie

my '83 CJ5, with a 258, 4 speed, and .273 gears (that i was going to swap out but never got around to) gets 25 or 26 mpg. till the gas prices come down, i like them tall gears.

Seem's like alot,you sure? If this is possible I'll sell my TJ asap to find one like yours.

LongueCarabine · 05-26-2008, 08:45 AM

My 85 CJ7 with 150 Iron Duke and 4 speed T4 is currently getting about 18 mpg, but I think I can tweak it a bit by tuning the carb.

Of course, I rarely go above 50 in it, it's not my daily driver, I usually just take it to town or on trips into the wild on weekends.

LC

**Pacfanweb** · 05-26-2008, 08:48 AM

Quote:

Originally Posted by xxxflhrci

Your calculator is broken.

Agreed. That seems WAY high.

**Mike Romain** · 05-26-2008, 10:20 AM

I have the 258 with 3.31 gears turning 33x9.5 BFG muds and get a nice 22 mpg highway loaded for camping if I keep it under 65 mph. I got the same or maybe a bit better with my old engine and 31" tires even taking into account the tire size and speedo readings. I do remember some trips at over 25 mpg. Tailwind..... One tankfull at 28 even. 'BIG' tailwind and friendly transport truck driver blocking for me.

I 'do' have the emissions computer sleeping with everything manually tuned and need 91 octane to get the good mileage while still being able to pass emissions.

It went down to 18 on one trip because I had the carb set wrong and boy did my wife get on my case for that.

cjwillie · 05-26-2008, 12:18 PM

no, my calculator's not broke. i didn't believe it the first time i checked it. i have checked it several times since. most of my driving is on back roads at 45-50 mph. the best it ever got was on a trip to akron and back, about 100 miles, running 55-60. it got 25.8 mpg. mechanicals are all basically stock, body is fiberglass. i don't know if there's any real weight difference between steel and fiberglass but whatever is helping the mpg's, i'm not going to mess with it. this is my third CJ and both of the other ones got about half the mpg's. my son had a '94 YJ with a 4 banger and he only got 13 mpg. i figured this would be my last CJ, i'll never get rid of this one. it's the easiest vehicle i've ever had to work on. and it's never given me any problems in the 3 and a half years i've had it. as long as it gets this kind of mileage and doesn't break me needing repairs, i see no reason to get something else.

**80cj** · 05-26-2008, 12:53 PM

Older Willys/Kaiser 4 banger CJ's are geared low so don't expect fabulous gas mileage from them. I believe the highest rear gears you could get with one of those was 4.27. It was gutless and the 3 speed didn't help.

SuB8HaVeN · 05-26-2008, 09:20 PM

Quote:

Originally Posted by 80cj

Older Willys/Kaiser 4 banger CJ's are geared low so don't expect fabulous gas mileage from them. I believe the highest rear gears you could get with one of those was 4.27. It was gutless and the 3 speed didn't help.

X2. Not to mention with that 3 speed don't expect to see more than 40mph. If you find a Warn or Saturn overdrive you may do 50mph with an original Willys.

If you're wanting better gas mileage, a 4 popper CJ isn't going to do it. My 258 I6 with 3.31 gears does 12-13mpg.

CJ7VFR · 05-27-2008, 06:39 AM

Quote:

My 85 CJ7 with 150 Iron Duke and 4 speed T4

If your CJ is a 1985, then the engine is the AMC 150 ci four cylinder engine, NOT the Iron Duke.

The Iron Duke is a GM engine, and its 151 ci, and was replaced by the AMC engine starting in 1984.

I also have a 1985 CJ-7 with the AMC 150 engine, and I get a consistant 21 mpg out of it, and that is
with 30 inch tires.

I also do NOT have a cat-con anymore, just a straight thru pipe right thru the old cat-con so its
still there for visual inspection, but its not a functioning item anymore.

And, believe it or not, my Jeep has run CLEANER and it passes all the immission tests BETTER than
it ever did with the cat-con still working.

I have had it like this for about 10 years, and it still runs clean, which always amazes the guy at
the inspection station when I bring it in.

I do know that before I put the straight thru pipe in there, my Jeep consistantly got 16 mpg.

So loosing the converter gets me about 4 to 5 miles per gallon more, and a cleaner burning
engine.

Jim

**John Strenk** · 05-27-2008, 06:57 AM

CJwillie, are you running stock tires and lift? I could pull 21 mpg back when I ran stock. Maybe I'll go back to stock someday. Would never get my jeep moving with 33's and 2.73. My new JK get's better milage than my CJ does now.

cjwillie · 05-27-2008, 07:41 AM

yeah, i'm running 235/75R15 AT tires, with a 2" body lift by the PO. the 258 runs strong and smooth. with the high gears, it doesn't like some of the hills in western PA, but with the mileage i'm getting, i'll live with it. it only had 76,000 miles on it when i got from the original owner. it was always properly maintained and i have tried to keep it tuned and in good running condition. i haven't done anything special, just take good care of it. i also got all of the "go fast" stuff out of my system years ago, so i'm not in any hurry to get there. helps save some gas. i don't know, maybe this CJ is a freak getting this kind of mileage, but i like it.

**mnCJ7guy** · 05-27-2008, 07:59 AM

Quote:

Originally Posted by CJ7VFR

If your CJ is a 1985, then the engine is the AMC 150 ci four cylinder engine, NOT the Iron Duke.

Sorry if that confused anyone, I see it all the time around this forum. but really I have an 1980 and two hands that can't type.

Nice job on the hidden straight pipe and the 4-5 mpg gain