2011 Jeep Wrangler Unlimited Re-gear
11-30-2014, 04:34 PM
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2011 Jeep Wrangler Unlimited Re-gear
Hello and thanks in advance for any responses! I have a 2011 Jeep Wrangler unlimited AUTO with max tow package (3.73). It's got a 2.5" terraflex coil lift and 33" Nitto trail grappler and lots of other exterior mods bumpers etc. Anyways I just purchased a 2015 Forest river R-pod The camper weighs 2565 completely dry. I towed it home today from Western Maryland. I knew it was gonna be a dog coming through the mountains and it was. I have decided to regear and am looking a putting in 4.88 gearing. Any thoughts? should I go with 4.88 or 5.13?
11-30-2014, 05:42 PM
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Are you ever going to taller tires? Typical freeway speeds and distance? How much hill/mountain time?
Open the FAQ's stuck right to the top of this modified area and scroll down to the rpm charts. Use actual measured tire height, not mfg spec. For a so-so comparison, jump on the freeway and press the OD/Off button. That should get your rpm's up into the 2700ish range at 70 mph (equal to 5.38's with your current tires on the chart? or a bit over 100 rpm more than you would see with 5.13's.)
Open the FAQ's stuck right to the top of this modified area and scroll down to the rpm charts. Use actual measured tire height, not mfg spec. For a so-so comparison, jump on the freeway and press the OD/Off button. That should get your rpm's up into the 2700ish range at 70 mph (equal to 5.38's with your current tires on the chart? or a bit over 100 rpm more than you would see with 5.13's.)
12-01-2014, 01:22 PM
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Are you ever going to taller tires? Typical freeway speeds and distance? How much hill/mountain time?
Open the FAQ's stuck right to the top of this modified area and scroll down to the rpm charts. Use actual measured tire height, not mfg spec. For a so-so comparison, jump on the freeway and press the OD/Off button. That should get your rpm's up into the 2700ish range at 70 mph (equal to 5.38's with your current tires on the chart? or a bit over 100 rpm more than you would see with 5.13's.)
Open the FAQ's stuck right to the top of this modified area and scroll down to the rpm charts. Use actual measured tire height, not mfg spec. For a so-so comparison, jump on the freeway and press the OD/Off button. That should get your rpm's up into the 2700ish range at 70 mph (equal to 5.38's with your current tires on the chart? or a bit over 100 rpm more than you would see with 5.13's.)
12-01-2014, 02:16 PM
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Don't click the links, just scroll down. All of the sections are there.
Is it safe to assume that your 33's measure about 32" at typical inflation and load? If so, use 32 in the chart, and then try to decide what a comfortable freeway rpm will be. (this is where OD/Off will be useful, as it will put you fairly close to what 5.13's will feel like). Some people at sea level on completely flat roads can get away with less rpm/hp/torque, and those at altitude or who drive lots of hills or live in windy areas may like higher rpm's. And typical speeds play a factor also. The hp needed to maintain 50 or 60 mph is a lot different than what is needed to maintain 80 mph.
But, from looking at the chart, you will see that there isn't a huge difference between the 4.88's and 5.13's, it's only like 125 rpm at 70. So either will work fine, it will just depend on 'your' opinion of where you want the rpm's to be. (as noted in the first reply you got, this question is asked on a daily basis, so there are literally a thousand different threads to read through for opinions. Just be sure to note the specifics of who is replying to make sure they have the same engine/transmission, similar altitude, similar driving conditions, etc. Replies from people with a 3.6, or a 3.8 manual, won't be very useful to you...)
I personally like higher rpm's, but I spend most of my time at altitude. For my 3.8 auto 4door, I ran 5.13's with both 33's (32" measured) and 35's (33.5"). And then swapped to 5.38's with the 35's, and finally moved up to 37's (35.5").
Is it safe to assume that your 33's measure about 32" at typical inflation and load? If so, use 32 in the chart, and then try to decide what a comfortable freeway rpm will be. (this is where OD/Off will be useful, as it will put you fairly close to what 5.13's will feel like). Some people at sea level on completely flat roads can get away with less rpm/hp/torque, and those at altitude or who drive lots of hills or live in windy areas may like higher rpm's. And typical speeds play a factor also. The hp needed to maintain 50 or 60 mph is a lot different than what is needed to maintain 80 mph.
But, from looking at the chart, you will see that there isn't a huge difference between the 4.88's and 5.13's, it's only like 125 rpm at 70. So either will work fine, it will just depend on 'your' opinion of where you want the rpm's to be. (as noted in the first reply you got, this question is asked on a daily basis, so there are literally a thousand different threads to read through for opinions. Just be sure to note the specifics of who is replying to make sure they have the same engine/transmission, similar altitude, similar driving conditions, etc. Replies from people with a 3.6, or a 3.8 manual, won't be very useful to you...)
I personally like higher rpm's, but I spend most of my time at altitude. For my 3.8 auto 4door, I ran 5.13's with both 33's (32" measured) and 35's (33.5"). And then swapped to 5.38's with the 35's, and finally moved up to 37's (35.5").
12-01-2014, 02:35 PM
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Don't click the links, just scroll down. All of the sections are there.
Is it safe to assume that your 33's measure about 32" at typical inflation and load? If so, use 32 in the chart, and then try to decide what a comfortable freeway rpm will be. (this is where OD/Off will be useful, as it will put you fairly close to what 5.13's will feel like). Some people at sea level on completely flat roads can get away with less rpm/hp/torque, and those at altitude or who drive lots of hills or live in windy areas may like higher rpm's. And typical speeds play a factor also. The hp needed to maintain 50 or 60 mph is a lot different than what is needed to maintain 80 mph.
But, from looking at the chart, you will see that there isn't a huge difference between the 4.88's and 5.13's, it's only like 125 rpm at 70. So either will work fine, it will just depend on 'your' opinion of where you want the rpm's to be. (as noted in the first reply you got, this question is asked on a daily basis, so there are literally a thousand different threads to read through for opinions. Just be sure to note the specifics of who is replying to make sure they have the same engine/transmission, similar altitude, similar driving conditions, etc. Replies from people with a 3.6, or a 3.8 manual, won't be very useful to you...)
I personally like higher rpm's, but I spend most of my time at altitude. For my 3.8 auto 4door, I ran 5.13's with both 33's (32" measured) and 35's (33.5"). And then swapped to 5.38's with the 35's, and finally moved up to 37's (35.5").
Is it safe to assume that your 33's measure about 32" at typical inflation and load? If so, use 32 in the chart, and then try to decide what a comfortable freeway rpm will be. (this is where OD/Off will be useful, as it will put you fairly close to what 5.13's will feel like). Some people at sea level on completely flat roads can get away with less rpm/hp/torque, and those at altitude or who drive lots of hills or live in windy areas may like higher rpm's. And typical speeds play a factor also. The hp needed to maintain 50 or 60 mph is a lot different than what is needed to maintain 80 mph.
But, from looking at the chart, you will see that there isn't a huge difference between the 4.88's and 5.13's, it's only like 125 rpm at 70. So either will work fine, it will just depend on 'your' opinion of where you want the rpm's to be. (as noted in the first reply you got, this question is asked on a daily basis, so there are literally a thousand different threads to read through for opinions. Just be sure to note the specifics of who is replying to make sure they have the same engine/transmission, similar altitude, similar driving conditions, etc. Replies from people with a 3.6, or a 3.8 manual, won't be very useful to you...)
I personally like higher rpm's, but I spend most of my time at altitude. For my 3.8 auto 4door, I ran 5.13's with both 33's (32" measured) and 35's (33.5"). And then swapped to 5.38's with the 35's, and finally moved up to 37's (35.5").