Upsizing tires on OEM Wheels

[BillTex]

Hi All, a little background; Truck is 2006 Chevy Duramax carrying hard side camper. When tires were last replaced moved up to 265/75R/16 from the OEM 245/75R/16 on OEM 16 x 6.5” wheels. Tires are BFG Commercial T/A Traction, which have been pretty good, at 40k they will need replacement. Only issue I have seen with these is they are wearing on the outside edges more than I would like. Truck is used mainly for hauling camper and not so much as DD. So the majority of the miles are with heavy load and are aired at the 80 psi max. When not loaded I will run 55 psi all around to soften the ride. Tires have been rotated frequently, usually at less than 10k mile intervals.

This leads to my questions;
Is this wear around the edges related to running 6.5” wide wheels with the 265’s (recommended wheel size for this tire is 7” min)? I thought running high psi would help this, but I have not been able to get nice even wear across the tread after experimenting with various psi scenarios.

When I replace the 265’s (before next winter) I want to move up to 285/75R/16’s to gain even greater capacity on rear end for carrying camper, Anyone running 285’s on 16 x 6.5” OEM GM wheels with heavy loads?

I have seen comments about running wheels that are too narrow for the tire causing bulge which some say reduces sidewall strength and may even cause the bead to break when cornering. I have not seen a lot of real life experience to prove/disprove these theories.

If the consensus is that running an upsized tire on OEM 6.5” wheels is contributing to the edge wear on tires and may have other issues, I am trying to hunt down a set of 16 x 7” G 3500 series wheels…which apparently are rare as hens teeth…

Thanks for feedback,
Bill

 

[uncle]

A couple things come to mind.

There is an alignment factor designed into the truck, Kingpin Inclination Angle. The camber and factory wheel/tire combo is set up to intersect the load in the center of the traction patch. Either your camber is off or you have changed the intersection point in from the original design. Wheel offset or camber adjustment will be the easiest to correct this.

Brian

 

[BillTex]

A couple things come to mind.

There is an alignment factor designed into the truck, Kingpin Inclination Angle. The camber and factory wheel/tire combo is set up to intersect the load in the center of the traction patch. Either your camber is off or you have changed the intersection point in from the original design. Wheel offset or camber adjustment will be the easiest to correct this.

Brian

Thanks Brian, I presume this is referring to the wear issue....any comment on running that size tire on 6.5" wheels as far as sidewall strength/bead?

B

 

[txnight]

Thanks Brian, I presume this is referring to the wear issue....any comment on running that size tire on 6.5" wheels as far as sidewall strength/bead?

B

My suggestion is to stick with the 265 or move to a 235/85/16 tire. The 285 will not wear as well and you will see a significant amount of sidewall budge to accommodate the rim width.

There are lots of options in the 235/85 and you can get your pick of tread type. You will see some people move up to the 255/85/16 which is a skinny 33 to 34 inch tire. Very popular size for expedition vehicles but limited in availability and tread type. The most popular 255 is the BFG KM2 which is E rated with a 3400lb weight rating. Cooper is also rolling out a 255 tire but reviews are still out on it. http://www.expeditionportal.com/for...5-85-16s-ST-MAXX-is-coming-soon?highlight=255


Good luck in your search.

 

[BillTex]

Here is another thought- moving to 255/85/16's on the OEM wheels. This size tire would fall within recommended wheel width (6.5") and would keep me at the same load rating (123) as current 265/75/16. The narrower 255 may prevent some of the "squishy" feel of the wider 265?

Anyone running 255/85/16 and hauling heavy?

I am afraid that moving to the heavier/wider 286/75/16 may be even worse as far as sidewall/squishy feel...

Prolem with the 255/85/16's is I can only find them in an off-road tread? I prefer to run M/S rated tires here in the North East...

Tx, Bill

 

[txnight]

http://us.coopertire.com/Tires/Light-Truck/DISCOVERER-S-T-MAXX.aspx

These might fit your needs.

 

[BillTex]

My suggestion is to stick with the 265 or move to a 235/85/16 tire. The 285 will not wear as well and you will see a significant amount of sidewall budge to accommodate the rim width.

There are lots of options in the 235/85 and you can get your pick of tread type. You will see some people move up to the 255/85/16 which is a skinny 33 to 34 inch tire. Very popular size for expedition vehicles but limited in availability and tread type. The most popular 255 is the BFG KM2 which is E rated with a 3400lb weight rating. Cooper is also rolling out a 255 tire but reviews are still out on it. http://www.expeditionportal.com/for...5-85-16s-ST-MAXX-is-coming-soon?highlight=255


Good luck in your search.

Yeah...the 235 are only 120 load range...I do not want to go down in capacity...

 

[BCHauler]

I ran 255/85's on my Super Duty with a camper and thought the size was perfect. Decent load range, taller, fit the stock rims perfectly. Didn't like the mud terrain tread with the camper tough. If I was doing it again, I would buy the same size in the Cooper ST Maxx. My former neighbour was running those tires on his new Ram with a camper.

 

[BillTex]

I ran 255/85's on my Super Duty with a camper and thought the size was perfect. Decent load range, My former neighbour was running those tires on his Dodge with a Camper.

Was that on OEM wheels?
What width?
How were they in winter?

I am liking the Cooper 255/85/16's ...think I might get better sidewall stiffness with these on a 6.5" wide wheel than I am running my current 265/75/16 on 6.5" wide wheel...

Tx, Bill

 

[BCHauler]

Sorry, I was typing without looking and half of the post was missing. Just edited it.
Didn't use them in winter as I always ran dedicated winter tires.

 

[gsanders]

I currently run a 255/85 16 Cooper Discoverer ST on stock Dodge rims (7" width) on a 2001 Dodge Ram 2500 with the diesel. I also haul an ~1200 pop up camper and I used it as a daily driver without the camper. So far, I like the tire size. I switched from 285/75 16 Goodyear Duratracs that were on aftermarket rims and I noticed a difference. The tall, narrow tires provide a nice ride and there is less rolling resistance. I do think that the Discoverer ST are a bit soft in the sidewall for the camper, although they are D rated to 3,000 lbs. Like something else mentioned, you may want to check out the new Discoverer ST Maxx which also now comes in a 255/85 16 and is M+S rated. However, I have driven the STs in snow, ice, gravel, dirt two tracks, and pavement so far and I love them. My only issue is I think the sidewall is a bit soft with the camper on as I feel some sway during cornering. Good luck.

 

[BillTex]

I currently run a 255/85 16 Cooper Discoverer ST on stock Dodge rims (7" width) on a 2001 Dodge Ram 2500 with the diesel. I also haul an ~1200 pop up camper and I used it as a daily driver without the camper. So far, I like the tire size. I switched from 285/75 16 Goodyear Duratracs that were on aftermarket rims and I noticed a difference. The tall, narrow tires provide a nice ride and there is less rolling resistance. I do think that the Discoverer ST are a bit soft in the sidewall for the camper, although they are D rated to 3,000 lbs. Like something else mentioned, you may want to check out the new Discoverer ST Maxx which also now comes in a 255/85 16 and is M+S rated. However, I have driven the STs in snow, ice, gravel, dirt two tracks, and pavement so far and I love them. My only issue is I think the sidewall is a bit soft with the camper on as I feel some sway during cornering. Good luck.

Yeah...the Cooper ST MAXX are E rated at 123 load index (3415#)....I would not run a D tire with my load...

How would you compare the handling with camper of the 285 vs the 255 tires?

Thanx.

 

[BillTex]

I guess the question I have now, is which tire/wheel combo will give the best results for hauling the camper;

• 255/85R/16 Load range 123 (3415#) on the OEM 16 x 6.5” wheels (Mfg recommended 6.5”-8” rim)
• 265/75R/16 Load range 123 (3415#) on the OEM 16 x 6.5” wheels (Mfg recommended 7”-8” rim)
• 285/75R/16 Load range 123 (3750#) on the OEM 16 x 6.5” wheels (Mfg recommended 7.5”-9” rim)

Having just moved up to a heavier camper than our last one, the current BFG 265/75R/16 Load range 123 (3415#) on OEM 16 x 6.5” wheels are feeling a little squishy on the road (did not feel this with last camper…).

One thought is that running a tire on too narrow a wheel sacrifices sidewall strength and contriutes to poor handling as the tire is not properly supported. So you gain nothing by upsizing the tires and not the wheels.

Would love to hear from Folks that have been there/done that...

Bill

 

[txnight]

On that size wheel we run 235 and 255 tires with no issues on our farm trucks. We haul hay, cows, you name it and can't have tire issues. The tire is made for that size rim so that's what we run.

If you want a taller tire you get wider rims. It's just that simple. The downfall to the taller and wider tires is the rolling resistance and wear on your truck. Our farm trucks are well used so we try and take it easy on them where we can.

 

[BillTex]

On that size wheel we run 235 and 255 tires with no issues on our farm trucks. We haul hay, cows, you name it and can't have tire issues. The tire is made for that size rim so that's what we run.

If you want a taller tire you get wider rims. It's just that simple. The downfall to the taller and wider tires is the rolling resistance and wear on your truck. Our farm trucks are well used so we try and take it easy on them where we can.

Yeah...but the 255/85/16 is taller than the 265/75/16...the 255 is made for my 6.5"wd wheels though...
So on the farm trucks; you replace OEM 245/75/16 with 255/85/16?

Bill