SRW Tires

[Dave_H_M]

I tow with an F250 and am always concerned/watch the weight capacity of the tires. I see the folks referring to the weight ratings of the F350.

What kind of tires/weight ratings do the SRW 350's have that helps boost the hauling capacity.

Seems like only E Rated are available for my F250 with 17" rims. thanx

[Grit_dog]

^No idea. It happened about 10 years ago.
I bought a set of 295-70-17s that were probably mfd in 2010 or so. They were around 4000lb cap.
But it doesn’t matter as there are now literally countless options in 18&20” so it’s a non issue.
16s are out now as well, as they won’t fit on pretty much any truck from the last 15 years or so. GMs excluded until maybe the last 10 years.

[MFL]

RoyJ wrote:

Grit dog wrote:
^Its actually the 17” tires that are low rated, not the wheels.
At least from previous research back when I had 17s under the truck.
But same difference. 17s are no good for heavy hauling anymore. Make nice off road wheel size though.

I wonder why all 17 tires appear to be frozen at 3195 lbs weight limit, regardless of how big they are.

Starting at 245/75r17, all except the 37" are capped at 3195. Above a certain size, even the E rated are capped at 65 psi.

16s, 18s and 20s don't have this issue.

Found that out myself, after looking.

Jerry

[RoyJ]

Grit dog wrote:
^Its actually the 17” tires that are low rated, not the wheels.
At least from previous research back when I had 17s under the truck.
But same difference. 17s are no good for heavy hauling anymore. Make nice off road wheel size though.

I wonder why all 17 tires appear to be frozen at 3195 lbs weight limit, regardless of how big they are.

Starting at 245/75r17, all except the 37" are capped at 3195. Above a certain size, even the E rated are capped at 65 psi.

16s, 18s and 20s don't have this issue.

[Grit_dog]

I got 3600lb rating data on the 17s I had on my old Ram. They're not weaker. Too much thinking about this. Truck wheels basically don't break unless damaged.

[MFL]

Grit dog wrote:
^Its actually the 17” tires that are low rated, not the wheels.
At least from previous research back when I had 17s under the truck.
But same difference. 17s are no good for heavy hauling anymore. Make nice off road wheel size though.

I agree, the OEM tires on Dave's truck are likely 3,195 rated, and he could purchase more capable 17" tires to improve real world capacity. The larger wheels likely have a higher rating than the 17s though. I think, in 2012, no matter the tires/wheels, or suspension, 6,200 was the max RAWR of the 250.

On edit: I searched for a higher load carrying 17 inch tire, than 3195, and didn't find any, so likely not an option.

Jerry

[Grit_dog]

^Its actually the 17” tires that are low rated, not the wheels.
At least from previous research back when I had 17s under the truck.
But same difference. 17s are no good for heavy hauling anymore. Make nice off road wheel size though.

[spoon059]

Dave H M wrote:
That is what I am talking about Rob.

I don't see how the 350"s can be advertised as big load carriers if the tires are the same E rating as 250's. :h

Your 17" wheels aren't rated to carry the weight that 18s or 20s rated to carry. I'm sure if you look at your axle ratings with 17s versus a same year 2500 with 18s then you will see several hundred lbs difference.

[ACZL]

My $.02 FWIW. Had a '15 F350 SRW, CC, SB, 4x4, 6.7, GVW of 11,500 thinking it would be our last truck and more truck than I'll ever need. Well for the most part this was true. RV we had at that time was AOK w/ truck. Then we upgraded RV's w/ a much higher weights all around. Now mind you at time of me typing this I forgot exact size tires that were on the 350, but due recall them being 18" cuz I couldn't reach the 5th wheel hitch like I could be before on old 250. 1st year w/ the new RV and '15 350 was ok, BUT I was at max weight and then some especially the tires. Following year we decided on FL in summer time for vaykay and now the weight issue was nagging me, gut feeling in pit of stomach that would not go away as I just wasn't comfy going to FL in heat of summer and additional stress on tires. Yes I could have probly changed tires, but still at max weights otherwise. Ended up w/ a '17 F350 DRW and shot the concern about weight on tires out the window. Truck handles the RV like a hot knife thru butter, wife says she felt more comfy driving/towing the RV w/ the DRW........so all this added up assures me the right decision was made. I admit I never wanted a DRW and yes it STINKS on the snow, BUT for towing heavy, well it's the cats a$$. Still would like/prefer a SRW for everyday use, but not in the cards. Rob of western NY IMO summed it up best that despite what can be done to level, stable a truck etc, still does not make or change the weight ratings placed on it by Mfr. As a regular follower on here, it's been said many times that anything north of 15-15,500 is DRW territory. The newest of SRW trucks may have a higher GVW, but do you feel comfy w/ it?

[MikeRP]

Cooper makes an AT3 XLT in 295/70R18 that has 4080 lbs capacity. It is only 1 inch taller than the stock 275/70R18’s (3640 lb)and is almost negligible difference on my speedo vs gps. Many others make this size also that sticks to 80 psi.

So for my fifth wheel the extra 880 lb capacity theoretically translates to 4400 lbs additional fifth wheel weight at 20%. Of course I will never use that additional capacity but it does give me better wear characteristics since I’m running around 6600 lbs on the rear axle.

The first set of Firestone at tires lost a lot of tread on a trip to key west towing my fiver. The Coopers have a 60,000 mile warranty plus they are much better on the farm.

[Grit_dog]

RoyJ wrote:
If your friend used the same OEM wheels, I wonder how much it was due to improper sizing. I'm guessing he went up in both diameter and width, which may be the reason for poor handling.

Not saying it's impossible for a particular D-rated tire to bounce more, just haven't seen that myself.

^This.
Load rating is load rating. Aspect ratio, rim width vs tire width, sidewall height and the type of load all factor in.
12V makes a good point, albeit not an argument against D load tires as much as matching the load rating and tire size/aspect/width/type to the type of duty it will be seeing.

Example,35x 12.50 wide tires on 16x8 wheels on one truck, great for soaking up bumps at lower pressures (e rated btw) and good off road performance, low likely hood of popping a bead and decent on the highway although they wander a bit at pressures that don’t rattle your teeth (lifted 1 ton truck basically).
37x 12.50 wide tires on 20x12 rims on the other truck. E rated 65 psi max for close to 4000lbs capacity. Even at 45 psi front and 32psi rear, they track straight as an arrow and handle like it’s on rails with a 6000lb 32’ trailer hooked up.

The 35s on 16x8 s would have to be rock hard to exhibit good handling characteristics and still would have a little wiggle at high loads like the rear with a 5ver hooked up.
The 37s on 20x12s while truck too tall to tow a 5ver unless I want to pretend I’m one of those Joe’s heading to the dunes in Cali with a brodozer nose to the sky, will handle MUCH better.
2 completely different examples and in the middle, some nice rock hard OE size tires with not so aggressive tread on the rear axle will likely do the best job of controlling a big pin load.

[StirCrazy]

BurbMan wrote:

StirCrazy wrote:
when I bought mine to get the 11500 gvw package you had to get the 20" wheel option otherwise you could only get a 11000 gvw truck.

I have 12,300 GVWR with 18" factory wheels.

is that a cab and chassi? there was no option for that when I bought mine? or maybe it is because I was looking for a crew cab 4x4. i didn't look at any 2wd models...

Steve

[RoyJ]

If your friend used the same OEM wheels, I wonder how much it was due to improper sizing. I'm guessing he went up in both diameter and width, which may be the reason for poor handling.

Not saying it's impossible for a particular D-rated tire to bounce more, just haven't seen that myself.

[Cummins12V98]

Friends with a F350 4x4 SRW SB bought a big Alpha 40’ toy hauler. He wanted bigger tires than the stock E Michelin’s to look cool with more aggressive tread.

LS installed the Open Country D tires stating they had more load carrying capacity.

They headed to SoCal and by the time they got back to NW WA the tires were nearly worn out and the ride was horrible and BOUNCY. He went to LS and tore them a new one. They replaced the tires and placed them on different wheels so he could run around and look cool but Still have a set that he put on when towing longer distances.

I warned him about the tires before he left. He said oh you just hate LS. When he came home he stopped by to tell his story and apologized for not listening to me.

They said it was very scary at times. The Michelin E’s did not bounce.

[blt2ski]

RoyJ wrote:

Cummins12V98 wrote:

Not a good idea. You can get a D in a bigger size and carry more weight than an E but the D will be a very bouncy tire.

Les Schwab was famous for that switcharoo.

Remember though, even the letters are arbitrary - there are E tires that are rated 65 psi.

The actual ply construction are also all over the place. There's no guarantee a D "bounces" more than an E. I've had mud terrain Ds with much stiffer sidewall plys than highway Es.

I've not found D tires that carry the same weight as an E tire to be bouncy. Comparing a D 265-75-16 vs E rated 245-75 and 235-85-16's. All three are rated at 3000-3040 lbs. I found the 265s to be the better handling tire with that load. E rated 265's did not do any better with just 65 lbs in them. They both carried the load the same.

Wider lower profile tires IMHO generally carry a load better than a taller profile of the same diameter.

Marty