Advice on tires for a 2015 Ram 3500

Durango

Adventurer
So I'm aggressively shopping for a 2015 regular cab Ram 3500 with the 140" wheelbase. (This is normally the long bed but I'm ordering it without the bed.)The truck will either have a Tiger Bengal TX mounted on it or an aluminum flatbed and a popup camper.

So with the "popular equipment package" I'm specifying (the wife wants the 10 way adjustable seat) the tires change to "Firestone brand LT275/70R18E outline white lettering on/off road tires". Are these going to be adequate? (I hate changing out tires that are brand new.) My guess is we'll be at close to max GVW with the Bengal install (I believe around 10,300#) and substantially less with the flatbed/camper option.

Thanks for any help on this since I'm a tire dummy.

Steve
 

poriggity

Explorer
Depends on what you want to do with the truck. They are going to be pretty much street tires I'm guessing, but I'm sure they will work until you can justify new tires to yourself.
 

Buliwyf

Viking with a Hammer
Cooper STT LT275/70R18 Are the most well rounded Expo tires I've come across for fullsize. My favorite tire.

Goodyear Duratracs LT275/70R18 Slightly less aggressive. Softer rubber. AT-like snow grip. Smoother ride. Wiggly when new.

Kelly Safari TSR. Same as Duratrac. Harder cheaper rubber and standard belt materials. Better than DT's on sharp rocks. Most chain friendly tread pattern of the 3 listed here, making the Kelly a popular choice for logging and patch work.

nothing wrong with burning up the factory Firestones. FYI: Factories spec odd tires that help meet EPA and Cafe laws. Kinda the way Home Depot and Lowes can spec a cheaper than normal Dewalt drill and force Dewalt to make it instead of just selling Dewalts hardcore pro drills. Not ever as good as aftermarket tires IME.




Any decent Dodge dealer, maybe even the Dodge factory, will be glad to swap tires for you. Ford will put any tire you want on any truck you order, just ask. Dodge is likely the same. The stock listed tires are for the going to the dealer lot models. To the best of my knowledge they'd be glad to stack a set of your choice tire next to the wall when your truck is rolling down the assembly line. At least that's the way it was last time I was at the factory. The tire machine corner is a fairly slow, boring part of the factory. Giant machine mounting tires way quicker than trucks being built. Plenty of time for that guy to $%^& around.

The question is, will you save any money if the factory puts custom tires on your truck compared to pulling the tires off yourself and Craigs Listing them?

What gear ratio will that truck come with?
 
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Durango

Adventurer
What gear ratio will that truck come with?
Don't beat me up here but I'm looking at the 3.73 ratio with the 6.4 Hemi. (Sounds of disgust from the diesel fanatics in the background.) I realize between the gasser and the 3.73 I'm not going to be upping the tire size and I'm OK with that.

Steve
 

RoyJ

Adventurer
Don't beat me up here but I'm looking at the 3.73 ratio with the 6.4 Hemi. (Sounds of disgust from the diesel fanatics in the background.) I realize between the gasser and the 3.73 I'm not going to be upping the tire size and I'm OK with that.

Steve

Is there a reason you're looking at 3.73s?

I always emphasize the importance of considering transmission internal gear ratios when picking your rear axle. In the case of 66RE, it has relatively tall gears: 3.2:1 1st, and .63:1 6th. I'd HIGHLY recommend 4.10s, especially on a heavy truck.

On the other hand, my 1500's 8 spd ZF has a 4.7:1 1st gear ratio. So even with my 3.21 axle, it's equivalent to a 66RE with a 4.67 axle! I don't know why Ram has delayed putting the ZF into the HD trucks...
 

Durango

Adventurer
Is there a reason you're looking at 3.73s?
No. Someone just told me that they thought the 3.73 would be "fine". And I'm not just a "tire dummy". My ignorance extends to most things mechanical. :)

So then I'll explain we don't plan to do serious rock-climbing with this long bed 3500 Ram, However, we will use it to get into the high country which includes 4 WD roads. (Think the Alpine Loop north of Silverton, Imogene Pass out of Ouray or the White Rim in Canyonlands.)

Also the plot thickens because we do plan to pull our 2 door Rubicon (curb weight around 4,000#) some of the time. So given all of the above would you Mechanical Geniuses recommend the 4.10 axle ratio? (Like most of us we'll still be doing more highway driving with the unit that four-wheeling.)

I really appreciate the input.

Steve
 

Buliwyf

Viking with a Hammer
Yes, absolutely. 4.10 is the way to go for towing with larger tires. And those tires seem tall enough. I'd even go with 4.30 if they offer it. 4.56 is likely too much.

4.10 is what my truck has and I'm happy with it.
 

redthies

Renaissance Redneck
I agree on the 4.10s. I would consider Toyo AT II tires as well. They are a great tire!
 
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mattiep11

Adventurer
from one of my other posts: oh i run 3:73 rear end with the gasser!!


Give u the rundown and my reviews. All tires used on landscaping trucks 1500, 2500, 3500 silverados, with plows hauling loaded 20' trailers .... (1500)Cooper St 285's "load E"- great tire for everyday beatings.. Snow traction (can be studded)good until it gets icy, got 65k miles out of them.. great in rain no hydro plane. only got buried in the deep snow when the frame got up on a thick snow bank. Drove them on stone roads and don't pic up much rock. sand ok but dig unless u air down. City street drone got loud after 40000 miles but sounded good. Overall I would buy them in heart beat any day. Moab, telluride, and Toledo and several cross country trips with them.. Heavy but not to heavy..Lost 1-2mpgs overall. (2500) Goodyear Duratracs 285's "load E" 2nd set get about 45k out of them... City street drone gets loud at 30-50mph. wet weather watch out for the tar on the streets it will slide and u won't stop. Snow traction great, rips the mud up just as well, never been stuck hit the hammer and they dig. sand they dig quick so air down. side lugs help dig as well. pulled out a couple huge screws and no punctures strong sidewalls. very heavy tire , about 3-4mpgs lost. (1500) Pro comp xtm "load e" 285's used primarily out in Colorado./ moab.. Great snow tire, suck when it gets icy. No hydroplane, great over washboard just hit the pedal and go. rock crawling they r super sticky when aired down, got buried plenty of times 600" snow year. Road noise not to loud 30-50mphs, heavy tire lost 3-4mpgs 40k on them . (3500) "load e" 265's Michelin at2 throw every little rock or pebble imaginable at your rig. great handling in rain and sand, not for gravel roads at all. not the best in any type of mud they get slick. Snow traction is totally laughable...(they say they tested these things and got good reviews and whatever else... get the chains or the studs cuz these suck worse than race slicks.i've had to use 4x just to get up a slight incline on paved roads in telluride ...no noise very smooth ride. drive all the mtn passes with them and had a few hunks out of the sidewalls..(imogene, ophir, the forks,alpine loop,etc.. great gas mpgs no other complaints but definitely not like the other tires above... WILL NOT BUY AGAIN.. came with the new truck
 

Durango

Adventurer
So do most people with 18" rims for with a 4:10 axle ratio? My 2 door Rubicon has 3.73 with some fairly massive tires BUT it weighs a LOT less! And our 2500 Ram has the 3.73 but again I'm thinking this new build will have slightly larger tires and weigh more. So.... ???

Thanks from a Mechanical Dummy

PS We seldom go over 65 mph on the freeway with the camper.
 

Buliwyf

Viking with a Hammer
So do most people with 18" rims for with a 4:10 axle ratio? My 2 door Rubicon has 3.73 with some fairly massive tires BUT it weighs a LOT less! And our 2500 Ram has the 3.73 but again I'm thinking this new build will have slightly larger tires and weigh more. So.... ???

Thanks from a Mechanical Dummy

PS We seldom go over 65 mph on the freeway with the camper.

Don't fear the gear. Especially if you don't go faster than 65.

A little gear makes a huge difference. The truck will feel more lively and solid towing. And only costs you about 300 more rpm. 4.10 or larger rear gears are a must have with slide in campers/trailers and gas engines. 3.73 makes more sense for unloaded trucks and low revving diesels.

For example, my 5.4L is fairly anemic at low RPM's, so Ford never even offered my truck with 3.73 gears. 5.4 + towing package = 4.10 gear immediately. Only larger engines were allowed to run 3.73, and that was mostly in a light duty fashion. Lawn care, city trucks etc. etc. Heavy duty towing needed a bigger gear.
 

Regcabguy

Oil eater.
I agree on the 4.10s. I would consider Toyo a AT II tires as well. They are a great tire!
Ditto on both counts. I've got the equivalent of 4.10's in an auto with my 3.73 axle ratio and a G-56 final drive ratio of 0.79.
My truck and camper weighs 9000# with wet camper,two occupants and the diesel and the ratio works fine. I wouldn't want higher gears with the load.
Toyo offers a 285-75-18 E-rated AT2 tire with a 4000# load capacity for future application. I think with the gasser,I'd stick to the stockers and see how it does.
I saw some Toyo 35-12.50-17 RT's mounted last week mounted. The guy got 40k out of his MT's but wanted to try something new. Quieter he said and the max weight to balance was 2.50 oz. Very typical of their products.
 
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RoyJ

Adventurer
So do most people with 18" rims for with a 4:10 axle ratio? My 2 door Rubicon has 3.73 with some fairly massive tires BUT it weighs a LOT less! And our 2500 Ram has the 3.73 but again I'm thinking this new build will have slightly larger tires and weigh more. So.... ???

Thanks from a Mechanical Dummy

PS We seldom go over 65 mph on the freeway with the camper.

If you tow relatively slow, it's even more important to get shorter gears. With the 3.73s and a .63 OD ratio, 6th would be absolutely useless at that speed, and very likely 5th as well, on anything but flat ground with a tailwind...

Is your Rubicon a JK? If so, I'm guessing it has a 6 speed stick? If that's the case, you have a .84 OD ratio, which is much easier to pull with a 3.73 ratio. Even if you have the 4 speed auto, the .69 OD is still better than the 66RE's .63 OD ratio.
 

RoyJ

Adventurer
BTW, here's a really nice gear ratio calculator:

http://www.grimmjeeper.com/gears.html

It has many popular transmission ratios preloaded - simply choose Dodge 68RE (same ratio as 66RE). Then type 3.73 for your axle ratio, and select P-metric for tire size, enter 275/75/18.

You'll see that at 65 mph, you have:

3.73 1475 rpm in 6th, 1927 in 5th, and 2379 in 4th
4.10 1621 rpm in 6th, 2118 in 5th, and 2615 in 4th
 

Timgco

Adventurer
With the amount of added weight, I would go with 4:10's as well. If you don;t like your 373 setup, you're looking at another 2K and warranty gone on the drive train.

I am new to the 6.4L and 410 setup myself. I have 35's on this 2500 also. Even with a 6 speed, I feel this is a good setup. However, if you added bumpers, camper, etc, I would want something like 4:56 gears.
 

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