48re and axle ratio

[PKnoerzer]

I have the 4. 10's. Empty they are too low but good for towing. With my 315 tires, the 3. 73's would keep me in direct for towing. I prefer the range from 1800-2000 RPMs and that's right where I am with OD on and the 4. 10's.

 

[snowmizer]

i've got an 05 , auto , 4. 10 . with stock tires and unloaded ,driving 65 mph (with cruise on ) i was getting between 20-22 mpg ( that was before ulsd ) i would think that 4. 10 would not heat up the trans. temps as much as the 3. 73 because you could stay in that sweet spot of 1800- 2000 without a searching trans.

 

[cmills]

If you are getting 20-22 mpg with 4. 10's thats pretty good, thats better than I've heard most people are getting with 3. 73's.



What RPM's will the 4. 10's run a 60-65 mph with stock tires?

 

[BGlidewell]

I have 4:10 and with the smarty on 3 or 5, it's like going into "full cloak" drive beyond 40. I can pass people before they realize I'm doing it.

@70 I'm just a tick above 2k with stock tires.

 

[cmills]

what kind of mileage did you get when your truck was stock?



thanks

 

[Matt400]

What RPM's will the 4. 10's run a 60-65 mph with stock tires?

Based on this tire size calculator: Tire size calculator it looks like a stock 265/70R17 is 31. 6" tall so plug that info along with the 48re's OD ratio of . 69 into this calculator: Engine RPM Calculator and you get an RPM of 1805 to 1955.



Since many cruise at 70+ you can see why 3. 73's are better for that.

Stock tires & 4. 10's lets you easily tow in OD at highway speeds.



Use that calculator playing around with tire sizes, speeds and gear ratios is fun. Pug in 1. 0 for the final drive to see what the RPM's do when you switch it out of OD.

 

[cmills]

thanks Matt, If I could get 4. 10's and get 20-22 mpg like snowmizer says he's getting that would be a no brainer for me, since I would say 80% of my driving is at 65mph or less I might be ok with the 4. 10's since that would keep the RPM's below 2000 which is where you said the fuel mileage starts to drop. But I have noticed that most of the used trucks I'm finding have 3. 73's so I might have to take what I can get.

 

[DPKetchum]

20/22 MPG with 4. 10s! No fooling. Guess my dual tires ,4x4 and 6th gear instead of a OD gear eats up about 5 to 7 mpg on mine!

 

[SBeretz]

I have a few buddys with 3. 73's and auto's and they pull 10K toy haulers and do very well on mileage and have plenty of power and they get right around 20-22MPG while cruising empty. The Cummins, Auto and 3. 73's are a great combo for unloaded mileage and do fine while pulling weight also, you just can't pull out of the hole like a lower geared truck can. I like my truck to cruise right at 2K RPM's. Seems to be the best compromise of power and mileage FOR ME... Scotty

 

[cmills]

test drive

I went and test drove an 06 dually today and I'm sure it had to have 3. 73's (no sticker in the glove box) because at 60 the RPM's were around 1600. I'm sure thats good for fuel mileage but it seemed like it was a little to low on RPM's if I would be towing much, I did turn the OD off then it was really screaming.



I would like to have some more imput on mileage with the 4. 10 and the auto if anybody could tell me, especially since I've got one person telling they get 20-22 and another saying 15-17.

 

[Matt400]

I would like to have some more imput on mileage with the 4. 10 and the auto if anybody could tell me, especially since I've got one person telling they get 20-22 and another saying 15-17.

That has so much more to do with the driver than you can imagine. Take my truck, I can pull off 20 pretty easy driving 1/8 to 1/4 throttle most of the time, always looking for lockup and low RPM's, letting off the throttle early to coast instead of braking generally babying the truck.



Now my son hops in and tries his best, says he is taking it as easy as possible yet it drops to 17.

 

[snowmizer]

rpm's on the 4. 10 with stock tires if i remember was 1700 - 1800, doing 65 with cruise on , straight highway driving. was doing trips from connecticut to upper vermont. conn. and mass. are relitively flat , vermont has some hills. hand calc. was allways between 20-22. this was empty and before any low sulfar or ultra low sulfar. believe what you want, i have no reason to b. s. anyone, thats what i was getting

 

[DPKetchum]

I've been in two trucks that got 20/22 mpg under/at 70. Both were 3. 73 auto two wheel drives. Mine with 4. 10s and a neighbors 05 auto with 4. 10s no way. Tried a Quad 30/60/100 box on mine and OVERHEAD showed 19 on a 50 mile interstate run on the 60 horse mode. Hand figure was more in the 17 mpg range staying under 2000 rpm. Without the Quad box my overhead has been withen . 5 of hand figures the few times I've checked it.

 

[cmills]

test drive

I brought home a 06 dually auto w/3. 73's and hooked it up to the trailer w/skidsteer,the trailer and skidsteer are around 12,000lbs. I first hooked my truck up and done a few test runs 40-60, 50-60, 50-65, and 0-60 and then done the same with the test truck. my truck was a little quicker in all but the 0-60 they were almost identical.



So I figure the auto with 4. 10's would probably do a little better than mine does, I know the 4. 10's will get a little worse fuel mileage than the 3. 73's do, probably about the same as what I get now since the auto with 4. 10's runs less RPM's than mine but it has more power so I figure it will average out.

 

[SBeretz]

So, does that mean you got a new truck? Or just tested an 06 out. I would think an 06 with 3. 73's would get you great pulling power and good mileage. Scotty

 

[cmills]

I just tested it, I actually thought it would do a little better myself, other than that it was nice.

 

[CPittman]

2K rpm in my truck is 65 mph w/ stock tires and 4. 10s - overhead reads just below 24 mpg for combined city / highway driving. Overall, I like the 4. 10s around town. It will flat leap off the line if some kid in a ricer wants to fart around w/me. Just hold it back with the brakes to build a little boost and let 'er rip. With 4. 10s T/C locks up early... just easy to drive around town.



It sucks on the highway w/ higher rpms unless the 5er is on the back. With the 5er hooked up the Cummins is smiling with the 4. 10s. Good gears.