I'm still trying to figure this one out. The JKU owners I've talked to all get about the same, or worse than me: anywhere from 12-20, all dependant on setup and driving style. Not-a-one has ever told me anything above 20.
Is 33s on a stock 2006 TJ with 3.73 gears asking for trouble?
- Thread starter CMTJ
- Start date
I'm still trying to figure this one out. The JKU owners I've talked to all get about the same, or worse than me: anywhere from 12-20, all dependant on setup and driving style. Not-a-one has ever told me anything above 20.
Whoops I was misreading something, I was thinking 42RLE transmission. Yep I would not normally recommend 4.88 for 33's with the 5-speed and 4.0L engine engine for a Jeep that sees much street or highway time.This actually took me by surprise, Jerry. Usually, you suggest 4.56 for 33's with the 4.0 5-speed combo. Regardless, I've run the numbers countless times and driven the setup once and I loved it, I look forward to getting it in the near future.
The highway rpm is still lower than the 3-speed auto with 4.56 and 35's or 4.10 and 33's.
I looked it up, 16 and 21. No way is anyone getting 30.
Of course, the 3-speed auto doesn't have an Overdrive.The highway rpm is still lower than the 3-speed auto with 4.56 and 35's or 4.10 and 33's.
Just throwing out there, but the wife's JKU gets about 20 - 21 mpg on the freeway. Regular gas and just going with the flow of traffic. We're taking it back to South Dakota in a week, so we'll see how it does on a highway road trip. JK's are funny critters, they do get noticably better mileage than a TJ, but it's not enough to replace a TJ over.
Roger Descoteaux
New Member
Loving the 32's on my rig running stock 3.73 gears with the auto...barely noticed any performance loss...
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kball05
Member
I plan on re-gearing. I have the 42rle and daily it so is 4.56 better or 4.88s how much dose it normally cost to re-gear?
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You should put info on your jeep in your profile. It'll make it easier.
Doing a quick search on some of your past posts, I see you're running 33's.
With the 42rle, and 33's, you want to regear to 5.13.
kball05
Member
Yeah I have been meaning to do that sorry. With 5.13s I'll still have good hwy performance?
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VirtualRussel
TJ Enthusiast
My wife's JKU typically gets 20-21 on the highway as well. She can get up to 22 on the highway if conditions are right. Around the city she typically gets 17-18 MPG.
Not to be blunt, but with 33's and 3.73 gearing, you DON'T have good highway performance right now.
I'm also assuming your jeep is an auto.
I used to run that combo, 3.73 and 33's, and I was amazed with the performance when I went to 5.13. My jeep had more low end power, could accelerate faster, better gas mileage, and I could pass and keep up with traffic.
kball05
Member
Yeah It dose suck bad now. Thanks for all the help I'll be looking at getting 5.13s
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Bob Darenberg
New Member
I just replaced my 31 ×10.5 with 33 ×12.5. I have a 2.5 inch lift. Regearing is a must for me. I contacted jeep and discovered I have 3.07 gears in my 00 TJ 4.0 manual. I'm surprised it spun my 31's, but I can definitely feel the difference on the highway and going up a hill/bridge. I'm looking at 4.56 gears with limited slip in both the front dana 30 and the rear Dana 35 since I have to replace the carrier as well. Though about 4.88 but that may be a bit too much.
As far as the look I like the 33's no rubs but a huge negative offset on my AR Baja rims.
As far as the look I like the 33's no rubs but a huge negative offset on my AR Baja rims.
4.56 will put you at 2750 rpm at 70 mph.
4.88 will put you at 2925 rpm at 70 mph.
I know a bunch of people with 4.56, they all love it. I know a few with 4.88, they all love it as well.
I don't think you could go wrong with either.
@Bob Darenberg, I tend to like a bit more than a bit less when gearing. I would say either will work for you; 4.56 if more of an on road rig, 4.88 if more off road.
Good decision, your 42RLE transmission's steep .69 Overdrive ratio makes a lower ratio like 5.13 a good choice.
Bob Darenberg
New Member
Thanks I think the target of 2750 @ 70 mph is what I'm looking for. Of course running down the interstate @70 mph with MT tires might be a little loud.