I have a 2012 Ford F-350. According to the sticker on my frame the tires (LT 245 75 R17E) have certain weight ratings......I have LT 275 70 R18E tires on my truck. Due to the bigger tires, does this change any of the weight rating and if so which ones and by how much?

It'll say on the tire. 275/70R18 came stock on my truck and they're rated at 3640 each. I believe 17" tires are generally rated lower but I don't know the number.

Maybe to clarify.....do the bigger tires change my GVWR or GAWR and if so by how much

You don't have the authority to change the GVWR or GAWR.

You're only as strong as your weakest link. If the tires you have now are stronger than what you previously had, you're still at your GAWR. It they're weaker than what you had, you may be weaker if that's the weakest point.

I know I can't change the GVWR or GAWR, only in this case Ford can!!!! But does it give me more GVW or GAW???

Bigger tires? Where do they make a difference | Good Sam Community

timmac
Explorer
May 28, 2016
Huntindog wrote:
timmac wrote:
azdryheat wrote:
You don't have the authority to change the GVWR or GAWR.

I do

That's great! Ihad no idea it would be so easy. Can you print me a new sticker for my truck?:R

This internet stuff just keeps getting better. More things that were previously hard or impossible to get are becoming easy every day.:B

Its called chassis modifications, G rated tires and air bags oh and a Banks Power Pack system to give it more grunt..

My 08 Bounder was rated by Fleetwood to tow 5000lbs and 500lb tonged weight but Ford rated the chassis for 5300lbs towing so with the said modifications above I can tow 6000lbs safely but can handle up to 7500lbs with 750lb tonged weight.
Grit_dog
Navigator
May 28, 2016
Tundra2084 wrote:
Ok reading from the Ford site at the following address the difference between 17 in tires and 18 in tires is a 100 lb rise in the GVWR and a 400+ rise in the RAWR

https://www.fleet.ford.com/truckbbas/topics/2012/12_SD_Pickups_SB.pdf

You can easily get higher rated 17" tires. The steelie rims are also up to the task.
Tundra2084
Explorer
May 27, 2016
Ok reading from the Ford site at the following address the difference between 17 in tires and 18 in tires is a 100 lb rise in the GVWR and a 400+ rise in the RAWR

https://www.fleet.ford.com/truckbbas/topics/2012/12_SD_Pickups_SB.pdf
Tundra2084
Explorer
May 27, 2016
Ahhhh. Ok sorry have been using the rear axle GAWR
My brain is starting to hurt
S_Davis
Explorer
May 27, 2016
Rear axle weight rating
Bedlam
Moderator
May 27, 2016
RAWR = rear axle weight rating
FAWR = front axle weight rating

BTW: Your front axle is a Dana 60 steer axle rated at 7250 lbs
Tundra2084
Explorer
May 27, 2016
Bedlam.... Now you have just thrown another weight rating at me. What is a RAWR?
Tundra2084
Explorer
May 27, 2016
IdaD. I am surprised too that the truck is rated on 245/75 R17E tires 5600 lbs front and 6290 lbs rear these tires I believe are rate in the 3400 lb range. But I have 275/70 R18 E tires with a 3640 lbs tire rating.
Bedlam
Moderator
May 27, 2016
It's not just the tire rating. You need to look at the frame, rim and suspension ratings too. Your weakest link is the maximum rating. In your case, the rims are rated lower than the tires resulting in the lower RAWR (can be verified on the Ford body build website specifications). The frame is the same as the DRW, the bare axle has a 9750 lb rating and the springs are matched to the published RAWR.
IdaD
Explorer
May 27, 2016
What's your axle rating? I'm surprised an F350 would have 17" tires on it if they're rated down around 3200 lbs or whatever.