Xtreme Recon with 4.88 Gears

[Old Jeeper]

Im kinda de

Missed it. Lol

No prob I have a sense of humor that is somewhat convoluted I guess. Been runing 4:88, 5:13 and 5:36s going back to the 60s. I like 4:88s as gear going to try it with 35 (NOT 315s) to see how well it works. I am down here in FL, nothing but flat and sand and the mud and I don't do any of those, I am a rock guy.
My JKR RECON was FAST, Borla Dual exhaust, chipped engine, CAI and it had 4:56 all installed by the previous owner, he traded it in on a 392. When I went to order my 2023 and saw 4:88s I said that is a GO. I ran them on my TJ for right at 100k miles on 37s. Thinking with the V6 and I may chip it it will scoot around town, no need for 37s out here, guess I need to pack bags and head out to Moab for month or so.

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[jayteal]

Or those with manual transmission. Or those who live at elevation. Or those who do a lot of rock crawling.

Yep - I have an 18" JLUR with a manual and just ordered a '23 manual with the 4:88 option and will be on 315 BFGs. Excited to see the difference from the 4:10 to the 4:88s

 

[Jmos4]

Hi,

Originally you could only get 4.88's with a Rubicon and a manual transmission, that was 22, this year seen a few automatics with it on there, wish we could have ordered a XR 6mt 4.88's from the factory but is what it is, nice they offer the ratio as much cheaper getting them new vs regearing later.

35's with a 6mt 4.88's works well, betting a A8 you could run 37's with them.

Regards,
Jim

 

[grimmjeeper]

Does this mean we can buy factory 4.88 gears and have them installed for those with 4.10/4.56 looking to go to 37's?

Or are we stuck buying after market brands only?

The shop that does the install will usually get good quality gear sets. There's nothing magical about OEM vs aftermarket. In fact, there are only a few manufacturers and many brands all come off the same assembly line.

But if you really want OEM gears over aftermarket, ask the shop and they'll be able to get them.

If you go to a dealership, your options are limited and the price will be higher. And they may not want to do the work at all.

 

[COJeeper]

I got the 4:88s on my JLR, of course it did not come with 35s, so I just bought set of GY Druatrac 35x12.50x17.

My poor 33s are spining like tops, feel sorry for them. Noted we paid the same thing for the 4:88s. One of the things I have noticed is that prices for the same thing often vary on Jeep. When I was doing builds on line at Jeep.com every build would change in price from day to day, crazy...

Also you window sticker shows 19 mpg in the city, mine shows 20, my REALITY is 13. Have not had a chance to drive on the highway yet, but doubt the 24 number. I only have 216 mi on it.

I have a '22 JLUR 2.0 and if I drive up to 50-60mph on a county road with no stops, I can get 24-25mpg. Over 60 and it starts dropping down. Based on the Jeep's computer I get an average of 20-21 typically with no highway driving. Driving out to Moab I get like 17, gross. I assume when I get 4.88s and 37s with 2.5" Clayton lift, I'll average 18 hopefully on the 50-60mph roads and 16 driving highways at 75-85mph.

 

[Old Jeeper]

I have a '22 JLUR 2.0 and if I drive up to 50-60mph on a county road with no stops, I can get 24-25mpg. Over 60 and it starts dropping down. Based on the Jeep's computer I get an average of 20-21 typically with no highway driving. Driving out to Moab I get like 17, gross. I assume when I get 4.88s and 37s with 2.5" Clayton lift, I'll average 18 hopefully on the 50-60mph roads and 16 driving highways at 75-85mph.

My first V 6 in my JKR would deliver 19 mpg on the highway, I was amazed. My current 2023 only has 242 mi on it and I have attained speeds as high as 40 mph. Who know what will happen when I get it out on the road.

You have some good numbers and I assume those are taken from the dashboard, which I have found over the years to very accurate. adding the 37s will require a bit of adjustment due to going further on one role of the tire...

 

[Mgirls]

No prob I have a sense of humor that is somewhat convoluted I guess. Been runing 4:88, 5:13 and 5:36s going back to the 60s. I like 4:88s as gear going to try it with 35 (NOT 315s) to see how well it works. I am down here in FL, nothing but flat and sand and the mud and I don't do any of those, I am a rock guy.
My JKR RECON was FAST, Borla Dual exhaust, chipped engine, CAI and it had 4:56 all installed by the previous owner, he traded it in on a 392. When I went to order my 2023 and saw 4:88s I said that is a GO. I ran them on my TJ for right at 100k miles on 37s. Thinking with the V6 and I may chip it it will scoot around town, no need for 37s out here, guess I need to pack bags and head out to Moab for month or so.

Quick question for ya. You made it a point to say you’re going to 35s NOT 315s. Whats the big difference? Im actually wondering why a tire company makes them both if they are both a load E tire? For example, Nitto Recon Grapplers. Thanks for the help.

 

[Old Jeeper]

Quick question for ya. You made it a point to say you’re going to 35s NOT 315s. Whats the big difference? Im actually wondering why a tire company makes them both if they are both a load E tire? For example, Nitto Recon Grapplers. Thanks for the help.

The 315 is a metric tire and the 315 is the width in mm (and now it gets complicated) width of the tire multiplied by the aspect ratio, which is the height of the sidewall, x2 because there are two sidewalls per tire, divided by the wheel inch, plus the wheel size and if that doesn't make your head spin. The 35 is US and it refers to the height of the tire, not the width. The 315 Vs 35, they are very close in overall size.

 

[Mgirls]

The 315 is a metric tire and the 315 is the width in mm (and now it gets complicated) width of the tire multiplied by the aspect ratio, which is the height of the sidewall, x2 because there are two sidewalls per tire, divided by the wheel inch, plus the wheel size and if that doesn't make your head spin. The 35 is US and it refers to the height of the tire, not the width. The 315 Vs 35, they are very close in overall size.

Thank you for the detailed answer. I do understand but my question still remains. Usually and I say usually the whole point of the “p” series is because they are lighter weight. But if they are both load E and the heights and width is within mm’s, what’s the point/difference? Like I just put 315/60r20 Recons on my Jeep. I wanted “D” to save weight and soften up the ride but were out of stock so I went with the “E”. They spec out almost identical to the the 35x12.5. What did I lose or gain? Thanks for the help. Although since they’re on the vehicle now, that ship kinda sailed….lol

 

[Old Jeeper]

Thank you for the detailed answer. I do understand but my question still remains. Usually and I say usually the whole point of the “p” series is because they are lighter weight. But if they are both load E and the heights and width is within mm’s, what’s the point/difference? Like I just put 315/60r20 Recons on my Jeep. I wanted “D” to save weight and soften up the ride but were out of stock so I went with the “E”. They spec out almost identical to the the 35x12.5. What did I lose or gain? Thanks for the help. Although since they’re on the vehicle now, that ship kinda sailed….lol

Look back up on the 2 examples and you note Section Width, the 35 + 18 and the 315 = 12.7. The 35 is a LOT heavier. As far as both being E rated, this applies to "Carrying Capacity" aka Max Load. The 35 can carry 3195 lbs of weight at 65 psi, whereas the 315 carries 3195 lbs at 50 psi. They are both 10 ply "RATED" (does not mean they ARE 10 ply). The 315 is a lighter tire than the 35.

IOW the 35 is a bit tougher tire vs the 315, but they close. The 315 will give you a better ride to to a lower psi..

MISTAKE almost everyone makes: They move up to a tire that is bigger, badder and better. NOT knowing how much PSI to run they read the blackwall and it give the weight (3195 lbs @ 65 psi). So that tire with a weight on it of 3195 should run 65 psi. 3195 x 5 = 12,780 lbs...have you weighed your Jeep lately, does it weigh 12,780? NO, maybe ½ of that at best. So you mission if you chose to accept it is to determine how much PSI you put in that tire to carry its share of the weigh of your Jeep. Screw #2. The 65 psi resulted in a lot of dental work from fillings jarred out of the teeth. So they turn to the door jam and it says 37 psi. Well that does not work either since the psi applies to the OEM tire. starting to smell the coffee?

You need you use the water or dust or chalk test in order to ascertain your contact path and its resulting psi...

 

[Mgirls]

Look back up on the 2 examples and you note Section Width, the 35 + 18 and the 315 = 12.7. The 35 is a LOT heavier. As far as both being E rated, this applies to "Carrying Capacity" aka Max Load. The 35 can carry 3195 lbs of weight at 65 psi, whereas the 315 carries 3195 lbs at 50 psi. They are both 10 ply "RATED" (does not mean they ARE 10 ply). The 315 is a lighter tire than the 35.

IOW the 35 is a bit tougher tire vs the 315, but they close. The 315 will give you a better ride to to a lower psi..

MISTAKE almost everyone makes: They move up to a tire that is bigger, badder and better. NOT knowing how much PSI to run they read the blackwall and it give the weight (3195 lbs @ 65 psi). So that tire with a weight on it of 3195 should run 65 psi. 3195 x 5 = 12,780 lbs...have you weighed your Jeep lately, does it weigh 12,780? NO, maybe ½ of that at best. So you mission if you chose to accept it is to determine how much PSI you put in that tire to carry its share of the weigh of your Jeep. Screw #2. The 65 psi resulted in a lot of dental work from fillings jarred out of the teeth. So they turn to the door jam and it says 37 psi. Well that does not work either since the psi applies to the OEM tire. starting to smell the coffee?

You need you use the water or dust or chalk test in order to ascertain your contact path and its resulting psi...

Gotcha.... Thank you! Just had them installed so will have to chalk them. Currently running at 33psi. Let me preface the next statement by saying, sit down.. It's a mall crawler for my daughter...(I KNOW) She likes the look and this is her second JL. May have gone up a curb once. But what our little girls' want, we give them...lol

 

[Old Jeeper]

Gotcha.... Thank you! Just had them installed so will have to chalk them. Currently running at 33psi. Let me preface the next statement by saying, sit down.. It's a mall crawler for my daughter...(I KNOW) She likes the look and this is her second JL. May have gone up a curb once. But what our little girls' want, we give them...lol

Red Jeep bottom right: NOTE the tire, BFG, 37 x 15.50 x 17 KM2. This is my off road rig, that is a SERIOUS off road tire and look at it I drive it on the street at 16-18 psi, off road 3-5 psi, I run bead locks.

NOTE the dust on the tire, a perfect contact patch...

 

[Mgirls]

So this is the Nitto page. I did the LT315. It was versus the 35x12.5. ALMOST every number is identical. The 315 is actually taller and wider, but splitting hairs.

LT315/60R20 E 125/122S	218320	16.3	34.88	12.72	9.5-(9.5)-11.0	3640 @ 65	69.84
LT325/60R20 E 126/123S	218220	16.4	35.35	13.03	9.5-(9.5)-11.5	3750 @ 65	71.10
34x11.50R20LT E 121R	218330	16.9	33.50	11.42	8.0-(9.0)-10.5	3195 @ 80	61.88
35x11.50R20LT E 124R	218090	16.9	34.53	11.42	8.0-(9.0)-10.5	3525 @ 80	60.65
33x12.50R20LT F 119R	218050	16.9	32.52	12.52	8.5-(10.0)-11.0	3000 @ 80	62.68
35x12.50R20LT F 125R	218020	16.9	34.53	12.52	8.5-(10.0)-11.0	3640 @ 80	70.35

 

[Tool Guy]

Look back up on the 2 examples and you note Section Width, the 35 + 18 and the 315 = 12.7. The 35 is a LOT heavier. As far as both being E rated, this applies to "Carrying Capacity" aka Max Load. The 35 can carry 3195 lbs of weight at 65 psi, whereas the 315 carries 3195 lbs at 50 psi. They are both 10 ply "RATED" (does not mean they ARE 10 ply). The 315 is a lighter tire than the 35.

Something is not right in that chart, no way a 35x12.5R17 has an 18" section width.

 

[Old Jeeper]

Something is not right in that chart, no way a 35x12.5R17 has an 18" section width.

Screen shot, I too wondered about it and thought it might be CMs but that does not seem to computer, I can only assume it is a mistake.

if the tread width is 12.50 on a 70 profile tire then what would be the outer section width???? dunno

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