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1) According to a jeep wrangler owner on jeepforum.com, he upgraded to 4.88 gears and 33 tires and he gets 17-18mpg and its a rubicon (i do believe)!! Its also a 6speed manual.

2) Wouldnt you get better fuel milage if you had stock gears and larger tires??

3) Does anyone else experience getting such high mpg with 33s and 4.88s and would you recommend this setup for a DD rubicon?


thanks
 

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I actually ran 33's with 4.10 gears in my SOA YJ and got 16-17 MPG out of every tank. Now with 4.88's, I would think that if you drove over 50 MPH it would be like you had a fuel leak in your truck, but that is just my assumption after running my setup. I know that with 35's I get worse mileage than stock with the 4.10 gears (Don't really want to spend the money on my 44's). This is because the engine has to work harder to turn the larger tires and you use more gas to do so...
 

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I run 33 with the stock 3.73 gears and get 17-20 mpg. There was a tire chart to gear ratio that told you what gearing to tire size would give you the best fuel/power ratio and it said 3.90 is the ideal gear set for 33's supposeddly. After that you start getting more power but loose mpg.
 

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I have 33's and 3.73's and get about 16-18 mpg. Like stated, 3.73's would put you into the better fuel economy grouping according to the gearing charts. The Jeep doesn't have as much power on the hills now though. If I drive like an old lady and stick to about 55 mph I can brush mid 19-20 mpg.
 

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I'd guess the numbers put up by the jeepforum guy is because he didn't correct the gear in his speedo. Not only will your speed be incorrect, but mileage would also be skewed.
 

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I get 17-19 on the highway with 33's and 3.07 gears with a 6 spd. I don't have a speedo gear so I made the adjustment for the tire size and what not.
 

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I'd guess the numbers put up by the jeepforum guy is because he didn't correct the gear in his speedo. Not only will your speed be incorrect, but mileage would also be skewed.
exactly. I get 11mpg with stock gears and 33's. With a 5 speed. I haven't changed my speedo gear yet. So the mileage is definitely off.
 

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hey binary, two ??'s for ya: Should I just get use to the whistle my TB spacer makes? I had know clue it would whistle to me like that until I installed it. Also, was that short shifter pretty easy to install. I'm about to get one and would like to do it myself. I'm just not sure if I would starting something I can't finish. I try to learn as I go.
 

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I can get 17-18 miles to the gallon. However, it has a huge amount to do with driving style. I don't wind it up, I'mm properly geared, and I keep it in as high a gear as I can without dragging down the motor. Most people don't drive that way. So yes, if you drive very conservatively you could see that kind of mileage.

If I drive it as most people do the mileage heads for the basement pretty quick.
 

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Also, was that short shifter pretty easy to install. I'm about to get one and would like to do it myself. I'm just not sure if I would starting something I can't finish. I try to learn as I go.
I just did the install for the Hurst short shifter, worth the money, and very easy to do. It took me about 1.5 hours and that was only because the front of my console is a pain to take apart (tuffy). If you can use a ratchet, you can install a shifter.
 

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Keep in mind that the mileage reading on your odometer will be reading LOWER than normal when you go to larger diameter tires. It's the same reason that your speedo reads LOW. Your tires travel a farther distance in one revolution than a smaller diameter tire would. The best way to see this is to have your spedo cal checked by AAA or someone. I once got a ticket for doing 83 in a 55 zone and argued with the cop that I knew I was speeding but not THAT fast. My speedo read 65-ish... Still was going to be a ticket. He said it was because I had bigger tires. I soon had it checked on a dyno and found that running 31's on a Mazda B2200 put me 13% off. For every 100 miles registered on my odometer I had actually travelled 113 miles. This also meant that when my speedo read 55 MPH I was actually going 62.15 MPH.
 
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