37 vs 38’s and 4.88 vs 5.13

[Zachanadandy]

You didn't mention that Jeep here:

It's real easy to measure for yourself? You can find guys who even used a dragy for before and after runs. A slight edge from take off is the only performance advantage looking at both graphs from 0-60... which is what the math and a little reasoning would have told you would happen. The only gain you get from gearing that you don't get from a downshift is in 1st gear. These aren't wide ratio 3 speeds where gearing is critical. We all have plenty of gearing for all scenarios thanks to the 8 speed.

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[Wheelin98TJ]

It's real easy to measure for yourself? You can find guys who even used a dragy for before and after runs. A slight edge from take off is the only performance advantage looking at both graphs from 0-60... which is what the math and a little reasoning would have told you would happen. The only gain you get from gearing that you don't get from a downshift is in 1st gear. These aren't wide ratio 3 speeds where gearing is critical. We all have plenty of gearing for all scenarios thanks to the 8 speed.

I was questioning if you owned or ever owned a 2019 3.6L JL.

Did you own one of those?

 

[Zachanadandy]

I was questioning if you owned or ever owned a 2019 3.6L JL.

Did you own one of those?

Our 2019 was a 2.0t. My wheeling buddies was the 3.6L. Similar builds, regeared at the same time. Lots of seat time and testing in both rigs. You can't argue the math or explain why a JK with 5.13s wheels/ crawls/ drives great on 37s but that final drive ratio of 18.4-1 just doesn't work in a JL or JT on 37s. Even the 19.27 of a JT or JL with 4.10s can't possibly work. No these rigs need at least a 24-1 ratio just to be drivable? Make it make sense? Explain the supposed gain of going all the way to 5.13s with this transmission? Instead you guys make inaccurate statements like you won't be able to tow, haul, or wheel if you don't regear... but I do and probably more than most. You'll only be able to drive slow... followed quickly with I don't drive my lifted Jeep 85mph so I'm not worried about what would be 2500+ rpms coming downhill with a tailwind for no reason. You guys argue both sides while not acknowledging literally every auto rig that was able to wheel and run big tires before the 8 speed. But 100 years of automotive performance history has proven... that 18-1 1st gear is enough for any rig, unless it's a JT or JL. You don't gain mpg overall or acceleration by going to deep gears with this trans and that's been proven by many people. The only ones that claim it's significantly quicker didn't actually measure it before and after. You will gain more power and acceleration with a tune period...at a fraction of the price.

 

[tysongladiator]

Our 2019 was a 2.0t. My wheeling buddies was the 3.6L. Similar builds, regeared at the same time. Lots of seat time and testing in both rigs. You can't argue the math or explain why a JK with 5.13s wheels/ crawls/ drives great on 37s but that final drive ratio of 18.4-1 just doesn't work in a JL or JT on 37s. Even the 19.27 of a JT or JL with 4.10s can't possibly work. No these rigs need at least a 24-1 ratio just to be drivable? Make it make sense? Explain the supposed gain of going all the way to 5.13s with this transmission? Instead you guys make inaccurate statements like you won't be able to tow, haul, or wheel if you don't regear... but I do and probably more than most. You'll only be able to drive slow... followed quickly with I don't drive my lifted Jeep 85mph so I'm not worried about what would be 2500+ rpms coming downhill with a tailwind for no reason. You guys argue both sides while not acknowledging literally every auto rig that was able to wheel and run big tires before the 8 speed. But 100 years of automotive performance history has proven... that 18-1 1st gear is enough for any rig, unless it's a JT or JL. You don't gain mpg overall or acceleration by going to deep gears with this trans and that's been proven by many people. The only ones that claim it's significantly quicker didn't actually measure it before and after. You will gain more power and acceleration with a tune period...at a fraction of the price.

Well... Wait! I went deeper gears and I gained. Other than mpg, I don't have any numbers. 0-60 times is something that I never even considered or cared about. But... Even though I didn't care about MPGs either, I do know that I gained.

 

[Wheelin98TJ]

Well... Wait! I went deeper gears and I gained. Other than mpg, I don't have any numbers. 0-60 times is something that I never even considered or cared about. But... Even though I didn't care about MPGs either, I do know that I gained.

Dude, just don't.

 

[Zachanadandy]

Well... Wait! I went deeper gears and I gained. Other than mpg, I don't have any numbers. 0-60 times is something that I never even considered or cared about. But... Even though I didn't care about MPGs either, I do know that I gained.

Around town and at low speeds you'll typically gain 1-2mpg. Conversely if you go deep like 5.13s or 5.38s you'll lose 2-3mpg at western freeway speeds. If you never drive long distances or never cruise above 70mph you could gain overall, but the averaged mixed economy breaks even overall. We do regular 600+ mile 1 way drives with the cruise control set at 85mph (just left on 1 right now but the wife's driving), so I lost more overall. Every use is different and if the pro-regear crowd was honest I wouldn't even bother posting in these threads. If they simply said with the 2 overdrives and the fact I rarely drive over 70mph I can go off the deep end of gearing with minimal drawbacks there's nothing to argue about. Instead they lie about not being able to wheel or tow or drive fast (which is the opposite of the reality of deeper gears). They argue automotive history while ignoring the huge difference in transmissions making gears in the 5s unnecessary. If you just want deeper gears and don't mind 2500+ rpm under the lightest loads then say that.

 

[tysongladiator]

Dude, just don't.

Hold on. I'm trying to see something.

 

[tysongladiator]

Around town and at low speeds you'll typically gain 1-2mpg. Conversely if you go deep like 5.13s or 5.38s you'll lose 2-3mpg at western freeway speeds. If you never drive long distances or never cruise above 70mph you could gain overall, but the averaged mixed economy breaks even overall. We do regular 600+ mile 1 way drives with the cruise control set at 85mph (just left on 1 right now but the wife's driving), so I lost more overall. Every use is different and if the pro-regear crowd was honest I wouldn't even bother posting in these threads. If they simply said with the 2 overdrives and the fact I rarely drive over 70mph I can go off the deep end of gearing with minimal drawbacks there's nothing to argue about. Instead they lie about not being able to wheel or tow or drive fast (which is the opposite of the reality of deeper gears). They argue automotive history while ignoring the huge difference in transmissions making gears in the 5s unnecessary. If you just want deeper gears and don't mind 2500+ rpm under the lightest loads then say that.

But, I didn't lose 2-3mpg at freeway speeds, I gained. I actually gained around town and on the freeway. Towing and not towing. Sometimes I drive faster than 70mph, but not when I'm towing. I get the best mpg when I'm out rock crawling.

 

[Panthers65]

But, I didn't lose 2-3mpg at freeway speeds, I gained. I actually gained around town and on the freeway. Towing and not towing. Sometimes I drive faster than 70mph, but not when I'm towing. I get the best mpg when I'm out rock crawling.

And this is what is normal.

For years deeper gears were a performance modification. The basic laws of physics clearly explains how torque multipliers work with different size gears resulting in different ratios. Apparently some have learned to defy the laws of physics, which I'm SUPER impressed with btw. Until I master this amazing concept of deeper gears not applying more rotational torque vs shallow gears all things being equal, I'll just stick with my 5.13's.

 

[Zachanadandy]

And this is what is normal.

For years deeper gears were a performance modification. The basic laws of physics clearly explains how torque multipliers work with different size gears resulting in different ratios. Apparently some have learned to defy the laws of physics, which I'm SUPER impressed with btw. Until I master this amazing concept of deeper gears not applying more rotational torque vs shallow gears all things being equal, I'll just stick with my 5.13's.

All things aren't equal because there's an automatic transmission involved. The thing that ends up equal is the final drive ratio 99% of the time at any speed higher than 1st gear. Yes, lower dif gears will have more torque in the same gear. Driven the same the 2 trucks will rarely be in the same gear. Slight gradeat highway speed 1 truck won't downshift and the other will. At that point the final drive ratio and torque output are the same and so are the rpms. More load, the guy with 5.13s downshifts to 7th and the guy with 4.10s downshifts to 6th. And now their final drive ratios are within 0.3 of each other. It's the math part of physics that's hard for most people. Lucky for them the Jeep handles all that mathing how much torque you need, what gear to be in to get there, etc automagically. I and several others I know personally and dozens I've seen post all lost mpg at western freeway speeds because being in 8th gear by half the speed limit isn't necessary or good for mileage as there's no 9th gear. If it worked as you describe why not just drive around in low range? Imagine all that extra torque all things being equal.

 

[Panthers65]

“All things are not equal because there is an automatic transmission involved. “

stopped reading right there, autos aren’t some magical device that defy a the laws of physics. The rest isn’t worth my time because it’s probably irrelevant or just flat wrong.

 

[MSFTMatt]

All things aren't equal because there's an automatic transmission involved. The thing that ends up equal is the final drive ratio 99% of the time at any speed higher than 1st gear. Yes, lower dif gears will have more torque in the same gear. Driven the same the 2 trucks will rarely be in the same gear. Slight gradeat highway speed 1 truck won't downshift and the other will. At that point the final drive ratio and torque output are the same and so are the rpms. More load, the guy with 5.13s downshifts to 7th and the guy with 4.10s downshifts to 6th. And now their final drive ratios are within 0.3 of each other. It's the math part of physics that's hard for most people. Lucky for them the Jeep handles all that mathing how much torque you need, what gear to be in to get there, etc automagically. I and several others I know personally and dozens I've seen post all lost mpg at western freeway speeds because being in 8th gear by half the speed limit isn't necessary or good for mileage as there's no 9th gear. If it worked as you describe why not just drive around in low range? Imagine all that extra torque all things being equal.

Honest question because I live about 1/8 of a mile as far west as you can get on the continental US…what are you considering western freeway speeds? Thankfully I typically only leave the coast for trips but I only drive between 65-75 even when I do. Never over 70 here on the coast on HWY1 with the highest speed limit of 65. Seems a lot of this argument is speed dependent? Or maybe I got lost back in the biblical verses

 

[Wheelin98TJ]

Honest question because I live about 1/8 of a mile as far west as you can get on the continental US…what are you considering western freeway speeds? Thankfully I typically only leave the coast for trips but I only drive between 65-75 even when I do. Never over 70 here on the coast on HWY1 with the highest speed limit of 65. Seems a lot of this argument is speed dependent? Or maybe I got lost back in the biblical verses

Max tire sidewall rating plus at least 10% for the rating being conservative.

 

[Panthers65]

Honest question because I live about 1/8 of a mile as far west as you can get on the continental US…what are you considering western freeway speeds? Thankfully I typically only leave the coast for trips but I only drive between 65-75 even when I do. Never over 70 here on the coast on HWY1 with the highest speed limit of 65. Seems a lot of this argument is speed dependent? Or maybe I got lost back in the biblical verses

Very dependent on Speed and use. Jeeps overall are better suited as a slower, trail type vehicles. Solid axles, 4 link with a panhard bar, and the aerodynamics of a refrigerator on wheels. Yes you can build them to be go-fast vehicles, but you're starting at a disadvantage.

As far as use, comparing the gladiator and the older wranglers. you're talking about a vehicle that is 20% heavier from the factory and has a 300-400% higher tow rating. different vehicles with different uses. The gears (and all other components) should match your use.

As for the Jeep actually spinning the tires and pulling the weight. It's easier for you to apply 500 Ft lbs of torque with a 4' long breaker bar than it is a 6" wrench because of the mechanical advantage. Yes you have to move the end of the tool 20X further to apply that torque, but we can all agree if we had to torque something down to 500 ft. lbs we'd all prefer the breaker bar. Your jeep is no different, if you have to move a 5000lb trailer, the Jeep has to work less with deeper gears to apply the same amount of torque. Yes the Jeep will move the load with factory gears, but there will be additional slip in the transmission which creates heat and reduces the life of the transmission. a 4cyl mustang II with the old 2.83 gears would probably pull a semi truck on a flat road, but if you do it regularly it will eventually break something.... I can drive a screw with a hammer, but at the end of the day it's not the right tool for the job. The deeper gears will in theory reduce the maximum top speed, but again, choose the right tool for the job.

 

[Zachanadandy]

Honest question because I live about 1/8 of a mile as far west as you can get on the continental US…what are you considering western freeway speeds? Thankfully I typically only leave the coast for trips but I only drive between 65-75 even when I do. Never over 70 here on the coast on HWY1 with the highest speed limit of 65. Seems a lot of this argument is speed dependent? Or maybe I got lost back in the biblical verses

75-80mph speed limits throughout AZ, NV, UT... and everyone drives 10mph over like everywhere else. With as often as we drive to our property in AZ plus wheeling trips to sand hollow and moab my Jeeps probably spend 100+ hours a year at 85mph. I know it's not the same use for everyone but who wants a Jeep you can't drive at the speed limit on the way to moab?

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