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Discussion Starter #1
I am interested to know how many RPM's you are turning at 75mph with the 68RFE in conjunction with @ 4.10 or 3.73 rear end ratio.

Please also mention if you are towing or empty.

Thanks!
 

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I'm turning 2150RPM at 75...thats with the stock 245/70 tires and 4.11 gears...whether you're towing or not doesn't matter, these transmissions are like a manual once the torque converter locks up...

Try this link out...its as accurate a calculator as any I've found...

Tyres1.com Tires, Wheels, Suspension - Calculators
 
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Discussion Starter #3
Are you happy with the 4.11's?

The reason I'm asking these questions it to decide if I am going to stick with 3.73 in the next truck or move to 4.10's

Thanks
 

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ACDC Chapter President aka VACAY!
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Can't remember at 75 but at 90 I'm turning just at 2k with these 33's...:thumbsup:...
 
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Are you happy with the 4.11's?

The reason I'm asking these questions it to decide if I am going to stick with 3.73 in the next truck or move to 4.10's

Thanks
I am happy with the 4:10 rear im my truck. My sold truck had 4:10s also. The 4:10s give your more towing weight capacity. Better to have a little extra, rather than not quite enough. Only you can decide on what is best for you. If any towing is in your future, or is even a remote possibillity, you will not regret having the 4:10s. We tow a 5er, which loaded is 15,000 lbs. So yes, I am 4:10s fan:thumbsup:.
 
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Discussion Starter #7
I am happy with the 4:10 rear im my truck. My sold truck had 4:10s also. The 4:10s give your more towing weight capacity. Better to have a little extra, rather than not quite enough. Only you can decide on what is best for you. If any towing is in your future, or is even a remote possibillity, you will not regret having the 4:10s. We tow a 5er, which loaded is 15,000 lbs. So yes, I am 4:10s fan:thumbsup:.
Thanks! Towing is about 90% of the driving that I do with my truck. It is not a daily driver.

I either tow a 6,800 lb boat or a Toy hauler that grosses @14.5K.

Speed limits out here have me towing the toy hauler 75-80 mph. I turn 2150 RPMS with my signature truck (48RE) and 3.73s. So with this trans, I'm glad I got 3.73's.

I anticipate ordering the a 2013 with the Aisin which has the same final ratio in 6th and the 68RFE.

The equation will also change if the Dually is available with the reported 18's..
 

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I also have a toy hauler...but 17000# loaded and have the 3:73 rear and 34,5 tires. Mine tows well in the hills out East and at 68-70 mph. At times, 4:10 would be nice on steep grades, but I love my fuel mileage. If I drove 55-60 all the time, 4:10 would be the way to go. At the speed you are talking...definitely go with 3:73.
 
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I'm running 2100 with 4:10's at 75
 
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08 running empty with 3:73 gears and 265 70 17 tires tacking 1800rpm's.
 
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At 60 mph I was at 1500rpm and at 70 mph i was turning 1800 rpm,
4:11, 68 auto, limited slip. I wouldn't have any other gear ratio.
By the time I get on freeway I am easily up to speed even if its 70 mph.
I won't tow my 15k toyhauler faster than that, prefer 60-65 mph.
 

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With my 08 6.7 Cummins ,68rfe I'm turning about 2200-2300 doing 80 mile an hour. For me I think that's a little high and I'd rather do the 373. just seems like it's revving up a little more than it should be cruising at 80. I also don't tow all the time though and I don't tow much when I do wheelers, and sleds regularly,, a car here and there. that's about it so it deathly depends on what you do with the truck day-to-day.
 

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My 12 has 3.73/stock tires. I am, and will be, towing in the Co. mtns., two lane roads, all/most summers and 4.10s would be great for that but I always downshift with the button before it billows smoke, and they do just fine. I also go to Az., in the falls, all interstate, and 2000rpm = 80mph = muy bueno, and the truck LOVES it! 3.73s are a happy medium for me.... good for the slow and the fast roads. Craig
 

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I'm at 1800 at 75mph 3.73, but i try to stay at max 65 mph when i tow then she sits at 1500 rpm
 

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My truck, a 2011 2500 4x4 LB CC, has 3.73 gears and stock 265/70/17 tires and turns 2000 rpm at 78 mph. I have pulled two campers through the CO rockies multiple times, my first camper was a 11K 5th wheel and my new camper is a toy hauler travel trailer that is about 8K loaded. It hasn't struggled with the grades even over the passes at continental divide. Going through some of the passes that are straighter I have had my cruise set and the truck doesn't down shift, and that was pulling the 5er. Pulling through the curvy 2 lane mountain roads I run in 4th gear manually and sometimes drop to 3rd through tighter turns. I don't think a 2500 needs 4.10 gears because if it is that heavy of trailer it needs a dually in front of it. The fifth gen Cummins have 3.42 gears unless they are ordered with optional gears, until either 2019 or 2020 when they returned to the standard 3.73 gears. I am glad my truck has 3.73 axle because I think if pulling anything of any weight 3.42 gears are too tall. My 2cents worth
 

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My 11’Ram 2500 4x4 6.7 CCSB with 35’s and a 4 inch lift with 3.73’s turns about 1600 @70mph in 6th gear (auto).
 
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