Gas Mileage & performance

Osprey22

New Member
Joined
Feb 21, 2006
Location
new bern nc
I have a 4.0 TJ 5 speed manualwith (I think) a 3.70 rear end. What kind of gas mileage can I expect to get when I put 33x12.50x15s. I get about 20mpg on the highway now. What about acceleration, will I lose a lot with the bigger tires?
 
Osprey22 said:
I have a 4.0 TJ 5 speed manualwith (I think) a 3.70 rear end. What kind of gas mileage can I expect to get when I put 33x12.50x15s. I get about 20mpg on the highway now. What about acceleration, will I lose a lot with the bigger tires?
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You'll lose it all, 5th gear, acceleration and a big drop in gas milage.
 
Expect somewhere between 14-16MPG. It will feel a little more sluggish and 5th will not be usable on any incline or a good head wind.
 
i get even less depending on the driving, I get anywhere between 12-16, and
5th is a pain up hills with zero acceleration.
 
I'm waiting to see some of the long-term stats. of acetone on seals and gaskets. I read a different study on acetone and the results were a lot less favorable. Most important component is the maker of the gas you use and what addatives they put in thier gas. Shell rated highest in the study I read.
 
I conducted my own peronal expirement late last summer...

As long as you use a quality gas, they all get about the same gas mileage.
I found some "Independent" study and pretty much said the same thing I told you. There was less than 3/4 a miler per gallon in each.

Amaco/BP, Mobil 1 , Texaco, Shell, Chevron, Exxon they're all OK.

I didn't see much mileage difference in the cheapo gas either.
 
Did you get any improved mileage in your own test? What ratio acetone to gas were you using? Did you use 100% acetone? There were a lot of variables to optimize the results. Everyting I've read says about 1 tablespoon to every 10 gals of gas. I read another article and it said too much acetone will actually decrease mileage. It didn't define "too much". I'm ready to experiment but I haven't had anyone say they did it and were happy with the results. I'm not all wrapped up with fuel economy but I do drive my TJ to and from work about 50 miles each way. Any improvement would pay for itself in a short time.
 
I havent done the acetone test yet, but I've got a friend of mine doing it though. of course he had to go on vacation as soon as he started so he wont be driving for the next week and i wont know his results until a few days after he gets back when he gets some miles on his tank. I drive my TJ all the time too and I would love to get some better mileage. I filled up today and got 13.7 on my last tank. not too good.
 
No acetone, I emptied a full tank of a particular brand of gas doing my normal driving. I live close to everthing, I rarely hit the interstates. 87 octane in a 97 Nissan pickup. I'm always close to the 24.5 mpg mark (+/- .5) In my TJ I run 33's with a 4.0, K+N Air Raid, Gibson CatBack Exhaust,4.11's, 87 octane per factory manual. I get around 14.5 mpg, about the same with 3.07's. If you're lookin to save fuel, drive something other than a TJ 50 miles a day. If you can get a cheap ass beater get it. Maybe an older civic, Turcel, or sentra. Gotta 94 sentra with 236k with 30+ mpg. Doesn't burn any oil... awesome car.

for model/make mileage check this out....http://www.fueleconomy.gov/
 
I reccomend a Ford escort or Mercury Tracer (same car), 91-95 model - but *only* with teh 5spd tranny. minimum 30 mpg, 33-34 more likely. Tranny made by Mazda (hence you want the manual). The 1.9l motor is doggy but easy to work on and cheap cheap cheap parts - could prob get the whole car for $800. my '95 Tracer has 200k miles and runs like a top. Paid $500 at auction, replaced whole tranny last summer for $200 when the internal linkage finally gave out. I drive it everyday and save the gas $$$ for 4runner toys.
 
Call me spoiled but, I want to drive my TJ EVERYDAY and get improved mileage/performance. I don't expect to get 30+ MPG but I think with the right set-up 20 MPG isn't out of the question. Intake/gas/exhaust/down hill/with the wind/whatever the right mix is. After I solve this problem I'll share it with everyone. After that I'll solve world hunger. :)
 
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