I just picked up an '01 Ram CTD QC 4WD with 3.55 gears. The truck has 315-75-R16 tires on it which I figure to be 34.6" tall by 12.4" wide. I intend to pull my a car trailer and '72 Cuda with the truck. Any idea how much of a difference I would notice if I switched to a 285-75-R16 tire? I figure that would be 32.7" tall by 11.2" wide. One problem I have now is the 315's rub up front when I make a tight turn. I am also getting about 15mpg with the 315's and was wondering if switching to the 285's would improve the gas milage?

Thanks for any help.

 

I would go back to 265/75/16 that the truck came with. If the previous owner didn't do a spedo correction than your mileage is off. You will probably realize 20 mpg mty with the stock tire size & it will be better geared for towing.

 

Not only will the difference in diameter affect your torque band (cruising RPM) but the difference in width may affect your rolling resistance.

If you have access to a GPS unit, use it to track your distance on a trip and then hand-calculate your MPG. You may be getting better than you think.

 

I kind of like how the 285-70-R17 tires "fill" the wheel well on the new Power Wagons. Would I notice much difference going from a 33" tire to the 265-75-16 which is about 31.65" tall? And by the way...are the Michelin LTX M&S tires pretty much the best you can buy or are there other cheaper alternatives that are just as good?

 

If your truck is strictly tow

id suggest even though they are hideous 235-85-16 Load range E, or 265-75-16 E. The tires you have now will handle the weight and will tow it no problem, I have 285 eight plies and have no basis of comparison with stock tires, but at mileage 16-18 city and 20-21 highway i dont complain. 285s look nice too. If you are gonna tow once in a while, the 285s will suffice. Heck i bought wally world tires, liberators, and loaded them down with 20K on a gooseneck, about 3500 ball weight and had no problems for eight plies.. I admit i was pushin it tho, Ten plies are and should be standard for towing alot due to the stronger sidewalls. IF its an occasional tow or light tows like mine usually are, then the 8 ply 285s are ok, If u want the ten plies, then Interco tires might have 10 ply 285s.. good luck

Tx

 

In answer to your questions, not really

if your truck is a manual and u take off on first low, then no, other than that there is just slight rolling resistance. The taller tires will be 1-3 mph faster at 2000 rpms, thus better highway mileage due to less revolutions. Smaller tires aparantly give u better torque, but due to common physics laws, and some common sence it is only natural, they are smaller, lighter, and will feel more sprightly due to the weight difference.

If you are on a budget, and can find these tires, TRIANGLE brand, those 10 plies are tough as sin and just under 100 bucks a tire... in size 265-75-16 I had a set on my old truck before i sold it. I bought liberators from walmart, which are about 33x11 inches wide on a 16 x 8 rim. They work really well, and for 429 a set of four cant go wrong for the price, however they only have 8K miles on them, no problems yet tho...


PS just FYI i have 3.5 gears as well,
2000 rpms im turnin at 69-70 mph nice for cruisin speeds!

And welcome to DTR! save urself some time and make this ur homepage, and fill in ur sig with ur new to you ram. congrats on ur purchase!! ull find all the info, and personal experience u need in this site
Good luck

Tx

 

Thanks for all the advice so far. The 315-75-R16 on the truck now are Cooper Discover S/T and are pretty much brand new....I would say less than 3,000 miles on them. The truck will only be used for occasional towing...probably will pull the Cuda a half dozen times a year to various tracks. I am thinking I will just try pulling with these tires one time and see how it goes. If no good then I'll consider spending all the money on new tires.

One problem though...is there any way to eliminate the front tire rub when I turn sharp with the 315's?

 

With the 315 and 3.55s, I probably wouldn't use O/D to tow, depending on the terrain.

 

Mine pops out of OD, then hunts going up a hill empty, can't imagine how it would be towing something.

3.55's and 315's.


phox

 

Granted your 01 is different than my 95/2500 4x4 ,5 spd with 3.55s but I couldent even imagine it. On mine you would never get goin in 2nd towing, the clutch would be gone soon. 5th would be worthless towing and not much good empty. My truck is stock and its my 3rd and they all have been the same pretty much in stock form so I know it not just my rig.

 

I had 295/75/16 BFG A/T's on my 02 and they fit perfectly. No rubbing whatsoever and I towed a 28' enclosed race car trailer all over the country. Perfect combo w/3.55's if you ask me. Add a comp box and you'll NEVER have to shift.

 

i have used the Michlon 285's on my last 4 trucks and they have done great. i just put new tires on my diesel and after reading input from a lot of folks on tire sizes , i changed this time to perreli 265's just to see if there is a difference. am leaving on a trip next week from michigan to Fl to La and back up thru Missori so will see.
My tire guy told me to give em a try and if when i got back i decided i did not like them he would swap me out back to the michlons so guess it is a no lose situation
the Miclons were 8 ply and these perreli's are 10 ply. michlons are about 50.00 per tire higher.

 

these are the perelli's i just got 110.00 each mounted balanced and lifetime replacement warrenty

http://www.tirerack.com/tires/BigPic...wall=Blackwall

 

I would try it and see how it performs, unless you're going awfully fast pulling in O.D. your RPM's won't be high enough for good tranny pressures to prevent slipping of Torque Converter, better to pull in 3rd. Fill out your signature so we know what mods you have if any. I installed front coil spacers on mine not because of rubbing the tires, just for more lift and looks, you would probably need those also to stop your rubbing. LT285 tires would give you better mileage also, and keep engine from lugging in 4th or revving too high in 3rd on hiway. If you do buy smaller tires and tow lots make sure you get "E" rated tires. I would stick with LT265 tires for optimum towing and performance, and mileage, keeps engine in "sweet zone". I just switched back to stock LT265/75R16"E"'s for summer towing for the above reasons, and (easily pulls in O.D.) at normal speed limit or SLIGHTLY above. I'm looking for an extra set of rims to mount big tires and put back on for late fall hunting and thru winter(I like the look of the bigger tires too much to get rid of) It's all about compromise.

 

my truck also came with the 315's and i have 3:55 gears. i don't ever tow more than 5K. so it isn't that bad for me. i have 305's now and i honestly can't tell the difference from the 315's. i don't know if i should be able to tell a difference or not. i have been considering going back down to 285's or even 265's but since the most i tow is a 16ft. trailer with a john deere gator on it during hunting season and a small sized tractor not so often. i don't know if i really aught to go back to smaller tires. i have the edge ez on it now and i still have a stock tranny, but i never race it and always take it easy towing. i think it will be alright eaither way i go but i am still stuck between trying 285's or going back to 315's.