Upgrading to 18" truck tires

[Bayley]

I have a 2013 Ram 2500 CTD 4x4 that currently has 245/70/17 tires on it. I am thinking about moving up to the 275/70/18 tires. Has anyone done this and are there any major draw backs in doing this?
Thank you for your input!

[B_O__Plenty]

There are some 285 and 315 Nitto tires that are still 17" that will increase your load capacity a bunch without having to buy new wheels..

B.O.

[bpounds]

The 265/70-17E are rated for 3,195#, while the 275/70-18E is rated for 3,640# (if I recall the values correctly)

If you do nothing else to the axle or suspension, it is worthwhile to increase the tire capacity. Greater margin of safety.

[JIMNLIN]

goducks10 wrote:

JIMNLIN wrote:
The LT275/70-18 E is a option for your 2500 Ram.

You upgrade the tires and wheels for more capacity but your 2500 truck is still limited by those small 6200 RAWR spring pack.

RAWR is limited by the tire rating. I have the same springs on my Ram 2500 as you get with 245 or 265 tires. My RAWR is 6000lbs. With 265 it jumps to 6200. Where's the limit? Looks to me like the limit is tire.

My point above was towards the OP '13 2500 Ram ......maybe I didn't word it right.

A GAWR is limited by the lessor of tires/wheels or suspension. In the OP case the rear suspension has the big AAM 11.5" axle.

He is upgrading to the LT275/70-18 E at 3640 lbs tires with matched wheel ratings. The rear spring pack has a 6200 ratings so without rear spring (or bags/etc) upgrades its the limiting component.
If he upgrades the rear spring pack to match the new tires and wheels capacity the truck will have the same load carrying ability as the 3500 SRW.

I've noticed on Fleet Fords website many of the wheels Ford uses has less capacity than the OEM tires capacity ....and in some cases its the spring pack with the lessor rating.

[goducks10]

JIMNLIN wrote:
The LT275/70-18 E is a option for your 2500 Ram.

You upgrade the tires and wheels for more capacity but your 2500 truck is still limited by those small 6200 RAWR spring pack.

RAWR is limited by the tire rating. I have the same springs on my Ram 2500 as you get with 245 or 265 tires. My RAWR is 6000lbs. With 265 it jumps to 6200. Where's the limit? Looks to me like the limit is tire.

[ScottG]

You can go from 17's to 18's or even 20's without changing the outside diameter or causing speedo problems. You just have to be very mindful of the size of tire.

[JIMNLIN]

The LT275/70-18 E is a option for your 2500 Ram.

You upgrade the tires and wheels for more capacity but your 2500 truck is still limited by those small 6200 RAWR spring pack.

[driveandfish]

I did it, 265/70-17 to 275/70-18 and I could not be happier. I found a set of 18" alloy Big Horn wheels from a 2014 on Craigs list for a good price. I went ahead and had the wheel size reprogrammed as the speedometer difference irritated me and I hear the shift points would be affected. I picked up almost 1000 lbs of capacity over the stock wheels and the extra safety margin makes me feel better when I run heavy.

[driveandfish]

I did it, 265/70-17 to 275/70-18 and I could not be happier. I found a set of 18" alloy Big Horn wheels from a 2014 on Craigs list for a good price. I went ahead and had the wheel size reprogrammed as the speedometer difference irritated me and I hear the shift points would be affected. I picked up almost 1000 lbs of capacity over the stock wheels and the extra safety margin makes me feel better when I run heavy.

[Coach-man]

Actually, "truck" tires are 19.5", not 18". Rickson tires will sell you the wheels, and a variety of 19.5 truck tires, as well as programing your computer to compansate for the larger tires. They claim 8 plus years on a set of tires!

[donn0128]

Price? That would be a deal breaker for me. I doubt other than bling you will gain anything worth while.

[N-Trouble]

There are lots of 18" tire options out there these days. Should be no issue with the diesel going larger diameter tire. Your speedo will now be off by a couple MPH at hwy speed. Best to check it with a GPS.

[bpounds]

I went from 17" to 18", but my originals were 265/70-17 and I went to 275/70-18, and it was on a Ford. Brand doesn't matter, but point is you are starting out smaller than mine. (just saw your edit on size - so you would be making the same size jump as I did)

On the positive side, you get a higher load rating, a tire that fills the wheel house better (looks) and more ground clearance.

On the negative side, you might have bed height issues under your fiver. Wheels - I found take-off OEM 18" wheels, which are hub centric. If you go with aftermarket wheels, I don't think there are any that are hub centric. They are all lug centric. Even though they are rated for the weight, I would hate running lug centric wheels under heavy loads. Fuel mileage - it will probably suffer a little bit. Power - it will suffer a little bit, but the CTD has plenty to spare. Tires will cost more. Not as good a selection in 18".

The pro list is shorter than the con list, but I'm happy that I did it. The added load capacity alone is worth it to me.

[Bayley]

Correction to my original post.....the current tires are 265/70/17.