Gears for 37" tires

[TheSolarWizard]

39” km3s on stock diesel gearing.
im happy with it quite frankly and I get about 23 in mixed driving when I keep freeway speeds below 70

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[morejeepsthanicancount]

I’ve now had 37’s on my Mojave for over a month. I live in Charlotte, so it’s relatively flat. I do use a Pedal Commander. I don’t tow anything. I do have a lift, front steel bumper, armor underneath and a winch. I don’t see any reason to change the gears. I may struggle when I head to the mountains a few times a year, but otherwise I really didn’t notice much difference. I still find 8th gear on my auto. Just my two cents. I think the Pedal Commander is the key...and no I don’t work for them.

Curious to know which pedal commander setting you use. Irrelevant to the thread, but I use Sport, +3.

 

[Deleted member 28696]

I have 37x20 tires, I had 5.13 gears installed, with a 3” lift, which was a great decision. No problem now with power or pep, better than stock. My MPG’s went up to 16.5 mpg at Altitude. Without the gearing i was getting around 13 mpg I had 4.10 rubicon gears, no pep, not enough. With 5.13s I get better mpg than the stock 33s now running 37s. It also shifts properly now, not getting stuck in rev mode.

 

[Boostnu]

I’ve been looking into having gears done in mine here lately. I’ve read a lot of threads and have debating between 4.88 and 5.13s. The shop is telling me to go with 5.13s but from what I’ve been reading I’ve been leaning more towards the 4.88s. Anyone running the 4.88s wish they would have went with 5.13s? Also anyone with 5.13s think it’s too much gear and wish they would have went 4.88s? Thanks

 

[Deleted member 28696]

I’ve been looking into having gears done in mine here lately. I’ve read a lot of threads and have debating between 4.88 and 5.13s. The shop is telling me to go with 5.13s but from what I’ve been reading I’ve been leaning more towards the 4.88s. Anyone running the 4.88s wish they would have went with 5.13s? Also anyone with 5.13s think it’s too much gear and wish they would have went 4.88s? Thanks

5.13s are perfect for 37” tires or even 38” tires. 4.88 will take you back to stock & 5.13s are even better. Getting better MPG than I was on stock 33” tires, no loss of power, shifts like stock.

 

[FLUndertaker]

I’ve been looking into having gears done in mine here lately. I’ve read a lot of threads and have debating between 4.88 and 5.13s. The shop is telling me to go with 5.13s but from what I’ve been reading I’ve been leaning more towards the 4.88s. Anyone running the 4.88s wish they would have went with 5.13s? Also anyone with 5.13s think it’s too much gear and wish they would have went 4.88s? Thanks

love my 513 with 37”. So glad I went with them over 4.88. Listen to your shop, they know of what they speak. With 2 overdriven gears there’s no reason not to go DEEP.

 

[WK2JT]

love my 513 with 37”. So glad I went with them over 4.88. Listen to your shop, they know of what they speak. With 2 overdriven gears there’s no reason not to go DEEP.

Exactly… if anything I now wish I had gone 5.38 for my 37’s. Kinda future proofs the 38’s or, gulp, 40’s I’m bound to talk myself into.

 

[Boostnu]

I was finally able to get my gladiator in for a regear. I’m pretty happy with the 5.13s you guys recommended. Thanks again.

 

[shrinkhead]

I was finally able to get my gladiator in for a regear. I’m pretty happy with the 5.13s you guys recommended. Thanks again.

After reading this entire thread lol I also decided on 5.13s (as the shop also recommended). What’s your rpms at 60 70 and 80 if you don’t mind ?

 

[Ted Striker]

An easy way to decide between 4.88 and 5.13 on 37's is what type of terrain you will be mainly driving on. If you're going to be up in the mountains, high elevations, lots of hills, etc., 5.13s are great for that. If you're going to be on relatively flat ground such as fire trails, mudding, back and forth to work on flat concrete, then 4.88s are going to be all that you really need.

That being said, even though I live in flatter than flat Houston, I still went with 5.13s because I plan on making quite a few trips to Colorado and wanted the extra gearing for the stuff up there. It still does very well down here as a daily driver, but 1st through 4th gear is pretty much non-existent. I'll hit 5th gear before I even get to the end of my street. But 6th, 7th and 8th are long and it's awesome to be on the highway and to be able to use 8th gear, 75 mph and cruising at 2100 rpms.

 

[Edub]

An easy way to decide between 4.88 and 5.13 on 37's is what type of terrain you will be mainly driving on. If you're going to be up in the mountains, high elevations, lots of hills, etc., 5.13s are great for that. If you're going to be on relatively flat ground such as fire trails, mudding, back and forth to work on flat concrete, then 4.88s are going to be all that you really need.

That being said, even though I live in flatter than flat Houston, I still went with 5.13s because I plan on making quite a few trips to Colorado and wanted the extra gearing for the stuff up there. It still does very well down here as a daily driver, but 1st through 4th gear is pretty much non-existent. I'll hit 5th gear before I even get to the end of my street. But 6th, 7th and 8th are long and it's awesome to be on the highway and to be able to use 8th gear, 75 mph and cruising at 2100 rpms.

This is what I needed to hear. I'm also in Houston and you know, if we take a road trip anywhere (when MPG matter the most) we find ourselves in mountains or at least hills. I just drove to Northwest OHV Park in Bridgeport (outside of Ft Worth) and I $hit you not, my average right now says 10.5 mpg. I spent more in gas then I did the entire weekend plus hotel. Especially in today's climate, MPG is more important to me than ever before. I cannot do another road trip like this again.

I'm currently on -

• 37 / 13.5 Ridge grapplers
• Clayton 3.5 lift
• bumpers, compressor, spare, tools and other recovery gear I brought just for the trip.

Is something wrong with my Jeep? It's the worst in this thread. this trip aside, I normally get 11.1 mpg. it was windy but still... Everyone who says they get 17 with 37's can KMA!!!

Sounds like 5.13 may be the way to go. I live on the West side of town but will need to start commuting to Sugarland soon enough and the price of gas is starting to make me anxious to the point of considering a cheap little commuter car (re-gearing is cheaper).

 

[Jeeperjamie]

This is what I needed to hear. I'm also in Houston and you know, if we take a road trip anywhere (when MPG matter the most) we find ourselves in mountains or at least hills. I just drove to Northwest OHV Park in Bridgeport (outside of Ft Worth) and I $hit you not, my average right now says 10.5 mpg. I spent more in gas then I did the entire weekend plus hotel. Especially in today's climate, MPG is more important to me than ever before. I cannot do another road trip like this again.

I'm currently on -

• 37 / 13.5 Ridge grapplers
• Clayton 3.5 lift
• bumpers, compressor, spare, tools and other recovery gear I brought just for the trip.

Is something wrong with my Jeep? It's the worst in this thread. this trip aside, I normally get 11.1 mpg. it was windy but still... Everyone who says they get 17 with 37's can KMA!!!

Sounds like 5.13 may be the way to go. I live on the West side of town but will need to start commuting to Sugarland soon enough and the price of gas is starting to make me anxious to the point of considering a cheap little commuter car (re-gearing is cheaper).

It's no joke, I get 17 o. 37 12.5 17 Kanati Trail Hogs.

 

[ShadowsPapa]

This is what I needed to hear. I'm also in Houston and you know, if we take a road trip anywhere (when MPG matter the most) we find ourselves in mountains or at least hills. I just drove to Northwest OHV Park in Bridgeport (outside of Ft Worth) and I $hit you not, my average right now says 10.5 mpg. I spent more in gas then I did the entire weekend plus hotel. Especially in today's climate, MPG is more important to me than ever before. I cannot do another road trip like this again.

I'm currently on -

• 37 / 13.5 Ridge grapplers
• Clayton 3.5 lift
• bumpers, compressor, spare, tools and other recovery gear I brought just for the trip.

Is something wrong with my Jeep? It's the worst in this thread. this trip aside, I normally get 11.1 mpg. it was windy but still... Everyone who says they get 17 with 37's can KMA!!!

Sounds like 5.13 may be the way to go. I live on the West side of town but will need to start commuting to Sugarland soon enough and the price of gas is starting to make me anxious to the point of considering a cheap little commuter car (re-gearing is cheaper).

Speed matters on these, especially lifted high. They are a sail raised high in the air.
WEIGHT - how much extra did you add? I dropped almost 2 just putting on a winch, skid plate and steel bumper.

 

[Muddzy]

This is what I needed to hear. I'm also in Houston and you know, if we take a road trip anywhere (when MPG matter the most) we find ourselves in mountains or at least hills. I just drove to Northwest OHV Park in Bridgeport (outside of Ft Worth) and I $hit you not, my average right now says 10.5 mpg. I spent more in gas then I did the entire weekend plus hotel. Especially in today's climate, MPG is more important to me than ever before. I cannot do another road trip like this again.

I'm currently on -

• 37 / 13.5 Ridge grapplers
• Clayton 3.5 lift
• bumpers, compressor, spare, tools and other recovery gear I brought just for the trip.

Is something wrong with my Jeep? It's the worst in this thread. this trip aside, I normally get 11.1 mpg. it was windy but still... Everyone who says they get 17 with 37's can KMA!!!

Sounds like 5.13 may be the way to go. I live on the West side of town but will need to start commuting to Sugarland soon enough and the price of gas is starting to make me anxious to the point of considering a cheap little commuter car (re-gearing is cheaper).

I don't know if something is wrong with your jeep and maybe mine. I have a Rubicon with 4.10 on 37s x 12.5 x 17 Ridge Grapplers on 3in lift and I drove it from NJ to Colorado in August '21 and January '22. It has a winch, half bed rack, a little armor and I carry maxtrax and fuel containers on side of rack. It also has a tonneau cover under the bed's half rack.

In Nov I had a RTT (in line with the top of my hard top roof since it's a half rack), a 270 degree canopy mounted to a roof rack on top of my hard top and to the side (so that created extra wind resistance). In January I didn't take the RTT or Canopy but did have a mountain bike on a hitch receiver bike rack. Not sure how much wind resistance that creates. I always drive about 5mph over the speed limit so on some parts of the highway the speed limits are 70 or even 75mph. Going 75 or 80mph is very inefficient, especially with the brutal kansas/Nebraska/Iowa/Colorado winds. I don't feel like the jeep is a slug with 4.10s (unless I'm off-road on a steep grade at elevation). I've towed my boat 4x on paved roads and it does OK. In all cases it just sucks gas.

These are calculated numbers: In November I got around 12.2 mpg traveling over 1700 miles. In January I got 11.6 mpg and there was a cold front/blizzard coming from the west - it felt like the headwinds were worse in January (although the west winds always seem bad). Driving back to NJ I averaged about 14.9 mpg both times. Around town I get about 13mpg since my drives are usually 10 miles or less round trip and the jeep never warms up enough.

I'm scheduled to go to 5.13s in mid April and then about 3 weeks later I'm driving out to Colorado again. I will be towing a small camper/trailer so unfortunately it won't be an apples to apples comparison but I will try to remember to post my thoughts on the gearing and gas mileage during the 500 mile break-in and post Colorado trip.

 

[Toyfrog]

An easy way to decide between 4.88 and 5.13 on 37's is what type of terrain you will be mainly driving on. If you're going to be up in the mountains, high elevations, lots of hills, etc., 5.13s are great for that. If you're going to be on relatively flat ground such as fire trails, mudding, back and forth to work on flat concrete, then 4.88s are going to be all that you really need.

That being said, even though I live in flatter than flat Houston, I still went with 5.13s because I plan on making quite a few trips to Colorado and wanted the extra gearing for the stuff up there. It still does very well down here as a daily driver, but 1st through 4th gear is pretty much non-existent. I'll hit 5th gear before I even get to the end of my street. But 6th, 7th and 8th are long and it's awesome to be on the highway and to be able to use 8th gear, 75 mph and cruising at 2100 rpms.

I live just outside of Houston but work in Houston. Been thinking about going to 37’s on my Mojave. What kinda MPG you getting?

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