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Discussion Starter #1
My wife and I are considering a large toy hauler purchase, and I'm concerned that my stock tires (which have a load capacity of 3525 lbs) will be dangerously close (or perhaps beyond) their rated capacity. I have considered going the Vision Hauler route (to maintain tire diameter) with 225/70R19.5 tires, but that upgrade is damn near $3k (seems like a lot for a 900 lb increase in rear axle capacity).

As an alternative, I could get the same tire I have now in a slightly larger size and get a limit of 4080 lbs and continue using my existing wheels. However, this tire's diameter is approximately 5% (34.3 vs 32.6 inches) larger than my current tires. Therefore, I'd be facing at least the following three potential problems:

1) Tire clearance. With stock suspension, would these tires cause any rub in the front while turning at full lock?

2) ECM calibration. The speedometer, odometer, and everything else will underestimate vehicle speed by 5%. How big of a deal is this? Is there any way to get the ECM recalibrated for these tires without voiding the warranty?

3) Drive ratio. Using these larger tires would have the same effect on gearing as replacing the 3.73 with a 3.54. Not exactly ideal since the goal here is to pull a heavy load. Have any of you pulled heavy trailers with larger tire sizes? If so, what was your experience (especially relative to the stock configuration)?

Thoughts on any/all of the above will be appreciated. Thanks!
 

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How about a 285/65R18? I think the load rating is 3640lbs
 

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How about a 285/65R18? I think the load rating is 3640lbs
My current tires are rated for 3525 lbs, so that would only give me an additional 230 lbs on the axle. Not worth the cost.
 

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I run Mastercraft ATX 285x75x16 load is 3680 they also have LT285/65R18 125\122S E OWL 8 - 10 8.5 11.6 32.56 54 3640
 

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How about a 285/65R18? I think the load rating is 3640lbs
That's what I went with (Cooper ST Maxx), but I was coming from stock 20's so the gain was worth it for me.
 

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I have 275/65r20 load rating of 3750
 

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First stop is the scale ,get a weight then get a weight with the trailer you want , if they won't let you do that find another dealer. before you spend a fortune on a nice big trailer you might consider a dually before you put a crapload of money into a "just enough" situation.

Don't buy junk tires ,there is always a good brand with the same rating, Mastercraft is not a good brand IMHO

19.5's not worth it for sacrifice in ride and you can get a standard tire rated close or likely above, they are a big PITA cause no-one wants to work on them cause they are a semi tire on a pickup and you have to have a tire store that works on both. Go to Discount or walmart and they won't touch them , go to a truck stop and they won't cause they are on a pickup. I speak from ManyMany miles of experience.

2" may give you some grief but also try a tire store that will mount one up and see, fronts are only ones that will give you grief.

Gear ratio is not a big deal until you get really big. speedo correction is available with a module inline in the speedo and does not touch the ECM and "should" not affect warranty.

Back to first part, do your homework with a scale and the truck and trailer and see where you will really be at. close is really OK , the rating is always figured low on everything to protect the MFG so close on the low side is really pretty OK.

All this is a project, I know you may not have the time but I often spend months if not years figuring out what I want and what works!
 
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Discussion Starter #8
First stop is the scale ,get a weight then get a weight with the trailer you want , if they won't let you do that find another dealer. before you spend a fortune on a nice big trailer you might consider a dually before you put a crapload of money into a "just enough" situation.

Don't buy junk tires ,there is always a good brand with the same rating, Mastercraft is not a good brand IMHO

19.5's not worth it for sacrifice in ride and you can get a standard tire rated close or likely above, they are a big PITA cause no-one wants to work on them cause they are a semi tire on a pickup and you have to have a tire store that works on both. Go to Discount or walmart and they won't touch them , go to a truck stop and they won't cause they are on a pickup. I speak from ManyMany miles of experience.

2" may give you some grief but also try a tire store that will mount one up and see, fronts are only ones that will give you grief.

Gear ratio is not a big deal until you get really big. speedo correction is available with a module inline in the speedo and does not touch the ECM and "should" not affect warranty.

Back to first part, do your homework with a scale and the truck and trailer and see where you will really be at. close is really OK , the rating is always figured low on everything to protect the MFG so close on the low side is really pretty OK.

All this is a project, I know you may not have the time but I often spend months if not years figuring out what I want and what works!
Thanks for the info! I don't even have a fifth wheel hitch yet; I just wanted to know what options were available. My truck with several hundred pounds of crap in the bed has a rear axle weight of 3900 lbs according to a CAT scale, so I know it will be very, very close to the 7050 tire capacity (or over it) with a ~3500 lb pin weight.
 

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Not a good idea to tow big, at or near the tire limit, with no cushion space between actual and max. :surprise:
Bigger taller tires, while increasing weight max, you're castrating the drive line power to pull.

Go smaller on the RV, or trade for what's needed...DRW. :grinn
 
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