5.7 w/ 3.55 vs 6.4 w/ 3.73

[RAM_Designs]

I'm looking into buying a new 3/4 ton RAM, upgrading from my current half ton 5.7L with 3.55 gears and 6sp tranny. I just hauled a 10k load (2k trailer and 8k worth of batteries) on a 300 mile delivery and decided that's about enough half ton truck hauling for me with that weight...I'm already looking into a CCLB 4x4 6.4L with 3.73 gears.

Will I see a big improvement in the ease at which the new 3/4 tows that load, even if it's just the 3.73 gears and not the 4.10? I know people are going to say "just order one with 4.10's"...not that easy when the truck I'm looking at is $12.5k off the sticker price and I'm maxed out on my budget. I can't order this same truck with 4.10's and get the same deal. I see some people swear by the 4.10's, and others say it's not a big difference.

 

[MADDOG]

The 4.10's will move the load a bit better from a dead stop and you might gain a low speed torque advantage going up a hill. In my experience with the 3.73/6.4L combo towing my 10K load routinely is that it will move the load just fine and is no slouch up a hill either.

I have not done a mileage comparison between the 4.10 & 3.73 combos but I suspect the 3.73 will be just a bit better over the highway just because at the same highway speed and gear, the 3.73 will spin the engine just a bit slower.

 

[opie]

I agree. I am not found wanting anything more pulling my 14,000 dump trailer loaded to or over capacity. 6.4 with 3:73

Sent from a field

 

[mtofell]

Will even if it's just the 3.73 gears and not the 4.10? I know people are going to say "just order one with 4.10's"...not that easy

I ran into the same situation - for some reason the 4.10s are pretty rare, virtually unheard of sitting on a lot and if you are lucky enough to find one it will never be the configuration or options you want. I think most guys with the 4.10s ordered them that way.

All that being said, I'm okay with the 3.73s and I tow a 10,500# 5th wheel. I'm going to guess what I tow will catch a bit more wind than a trailer of batteries so I think you'll be fine. At the risk of sounding like a broken record, the only real annoyance I experience with my truck is a pretty sizeable gap between 1st and 2nd gears. It's really only an issue pulling a steep hill at low speed. Once up to speed on the highway I can maintain pretty much any speed I want.

And you're in for a nice improvement with lots of stuff other than just power that will make your towing experience MUCH better.

 

[warwagon98xj]

I tow a 10k tt with a 5.7 2500 with 3.73s no problems

Sent from my 2PQ93 using Tapatalk

 

[RAM_Designs]

Appreciate the info guys. I'm talking to Dennis Dillon RAM up in Idaho and pretty set on one of their trucks with the 6.4 and 3.73 gears. It's a CCLB 4x4, so a bit bigger truck than what I'm used to dealing with. We don't have many big hills down here in TX, and if they are steep (still rare), it's not a long climb, maybe 30 seconds at the most, and then back down the other side.

I'm glad to hear people are happy with their 6.4/3.73 combo, I think it'll serve me just fine for what I'm wanting to use it for, which is fairly low profile towing (2ft load height max). My dad has basically the same truck with the 5.7, he's gonna be pissed that I'm getting a nicer one haha. He also hates the 4x4 knob thingy and will be jealous of my floor mounted stick for the 4x4.

 

[PippinAin'tEasy]

Got 11.8 mpg from Bluff Dale to Pensacola with #1300 in the bed. 6.4 w/ 3.73's 3500 CCSB 4x4.

"Oh, sweet debt. Thy name is Truck."

 

[RAM_Designs]

I got 11.0 on the EVIC going from Dallas to Galveston with that 10k load, averaged out to 13.8 hauling the trailer back home (24ft all metal car hauler). This was at maybe 100-500ft elevation and pretty flat roads, 600 mile round trip.

 

[RAM_Designs]

Also, can anyone with the 6.4 and 3.73 gears chime in with what kind of RPMs you're seeing at highway speeds like 70-75mph?

 

[smurfs_of_war]

Around 1800 or so. The tach is hardly scientific and the reading could be varied depending on the position of my head.

 

[RAM_Designs]

Yeah right now I hit 2k rpm right at 77mph or so...I notice my dad's 2500 with the 5.7 seems to be a good deal lower than myself and I'm wondering if he has the 3.73 or 3.42 gears. Either way, with his heavy truck, even in these low elevations, he's droppin a gear all the time on decent size hills. I'm hoping I don't have to deal with the same with the 6.4, since I am definitely not used to that driving a 1500 with hemi since I graduated high school.

 

[smurfs_of_war]

Without trailer in tow it rarely drops a gear. Often I pull rolling hills in 6th no problem.

 

[SouthTexan]

Yeah right now I hit 2k rpm right at 77mph or so...I notice my dad's 2500 with the 5.7 seems to be a good deal lower than myself and I'm wondering if he has the 3.73 or 3.42 gears. Either way, with his heavy truck, even in these low elevations, he's droppin a gear all the time on decent size hills. I'm hoping I don't have to deal with the same with the 6.4, since I am definitely not used to that driving a 1500 with hemi since I graduated high school.

3.42 gears are only available with a Cummins. The 5.7L 2500 has been either 3.73 or 4.10 unless it was a Power Wagon.

 

[RAM_Designs]

Thanks for the info, must be 3.73 then since the RPMs seem so low to me. Here's the truck I'm looking at: New 2016 Ram 2500 Tradesman For Sale in Caldwell Near Boise, Nampa, ID | Vin:3C6UR5HJ6GG212593

I can special order one that's pretty much the same price in Max Steel, but without the chrome appearance package or bedliner. Kinda undecided on if I want to special order 4.10's or if 3.73's would work fine. 32-33K is really at the top end of my budget, not sure if I want to go to 34-35k to special order exactly what I want. Not sure if 4.10 over the 3.73 at cruising speeds really makes a difference. I read someone saying they were only seeing something like 50-75rpm difference with the 4.10 vs the 3.73.

 

[mtofell]

Differential Gear Ratio Calculator | West Coast Differentials

Check out the gear ratio calculator..... it's pretty cool to see how the ratios change the RPMs.

I'm running the 3.73s and just can't justify the $$ to only go up to the 4.10s. The next jump is up to 4.56s which seems like too much but I'm not sure. I just changed RVs to my 10,500# 5th wheel (from an 8000# TT) a couple months ago so I'm still waiting to go through the camping season before making my final determination. I also may just lose my mind and go get a 3500 Cummins and be done thinking about it.

For the usage you describe I think the 3.73 will be more than adequate.

 

[Bigdaddy]

Thanks for the info, must be 3.73 then since the RPMs seem so low to me. Here's the truck I'm looking at: New 2016 Ram 2500 Tradesman For Sale in Caldwell Near Boise, Nampa, ID | Vin:3C6UR5HJ6GG212593

I can special order one that's pretty much the same price in Max Steel, but without the chrome appearance package or bedliner. Kinda undecided on if I want to special order 4.10's or if 3.73's would work fine. 32-33K is really at the top end of my budget, not sure if I want to go to 34-35k to special order exactly what I want. Not sure if 4.10 over the 3.73 at cruising speeds really makes a difference. I read someone saying they were only seeing something like 50-75rpm difference with the 4.10 vs the 3.73.

I order one from that same dealership, suppose to get it soon but of course I order one with the 4.10 gears which is about $125.00 more.

 

[RAM_Designs]

Well what's confusing is that with 285/70/17 tires and 3.55 gears, I have a little more RPMs than my dad's stock 275/70/18 tires and 3.73 gears...seems like the slight difference in tire size and gear ratio should even out, but I swear he's 200rpm lower at 75mph than myself. I don't even think he's at 2k rpm at 80.

 

[RAM_Designs]

I think I may just go 3.73 and adjust if need be when I do 35's after the stock tires wear out.

 

[MN-Ram]

That's a nice looking truck. If you order the maximum steel truck would it come with the Bluetooth phone and backup camera? They are both nice to have, especially on long road trips and hooking up to trailers.

 

[RAM_Designs]

That's a nice looking truck. If you order the maximum steel truck would it come with the Bluetooth phone and backup camera? They are both nice to have, especially on long road trips and hooking up to trailers.

The special order one that I asked about with max steel paint would not have the chrome package, backup camera, upgraded stereo, bedliner...I really want the bedliner. It would have the vinyl seats/floor which I like, mainly because the vinyl option is darker than the tan cloth seats. I'm really torn on just getting the black pearlcoat with chrome and a few extras, or just ordering a max steel one with not as many extras...both would be about the same, but I could order the max steel one with 4.10's. I'm also torn on 6'4" bed or 8ft bed...I'm an indecisive person, as you can tell.