285/75 on TRDP stock wheel
- Thread starter bmsmith15
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BlackWorksInc
New member
Eh, you might be able to fit it. But I don't know if I would want to risk it to be honest with you.
Half an inch may not sound like much, but I am running 285/70R17's on my 4th gen and they also recommend 7.5" min width (my factory rims are 7.5"). They "suck-in" at the rim's edge pretty good for a 11" wide tire. The manufacturer is recommending that minimum width because the bead is probably not seating properly on skinnier rims and cause the bead to fold and pop off the rim if you're aired down on obstacles. So it might work fine and it might not.
Half an inch may not sound like much, but I am running 285/70R17's on my 4th gen and they also recommend 7.5" min width (my factory rims are 7.5"). They "suck-in" at the rim's edge pretty good for a 11" wide tire. The manufacturer is recommending that minimum width because the bead is probably not seating properly on skinnier rims and cause the bead to fold and pop off the rim if you're aired down on obstacles. So it might work fine and it might not.
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BlackWorksInc
New member
Not width, height; the Width of the tire is 285mm (this is measured from the edges of the tread not the sidewall). "75" is the Aspect Ratio, this measurement indicates the percentage/ratio of sidewall height from rim to tread as compared to width (i.e. "75" means 75% of the width is translated to height of the sidewall, so the sidewall is 199.5mm roughly on a 70 series 285mm wide tire and 213.5mm on a 75 series tire.)
http://www.goodyearautoservice.com/content/content.jsp?pageName=TireSize
Diesel_Dog
New member
The guys on expedition overland specifically swapped out the trail rims (7.5 wide) for the TRD rims this season and put on 285 General Grabbers (which recommends a 7.5" rim). Seemed to have worked for them.
Mistaken
New member
Right. But adding height will definitely add some width as well. A 285/75 will be wider than a 285/70. Not by much, but it will.
Vrrooom
New member
Mistaken
New member
That's odd. On my last vehicle I was trying to stuff as wide of tires as I could and as I changed the sidewall it affected the width and would rub or not rub as it changed.
BlackWorksInc
New member
The Tire Section Width and the Rim Diameter are static measurements, they do not change (realistically speaking a 285 width tire can vary in width depending where on the treads they are measuring, for example if they do or do not include the sidewall lugs on some more aggressive tires; this would mean that say a Nitto Terra Grappler might be 285mm from the edge of the tread nubs, but a 285mm Toyo Open Country MT might actually be wider than that because they do not include the side lugs)
What I believe you are referring to is the "bulge" you see in the sidewall when the tire is aired up and loaded that will change some depending on the sidewall height, constructions, air pressure, and vehicle load; it's such a varying measurement that it is not specified or calculated for tire size. But it can cause fitment issues on vehicles that have a tight clearance on suspension components or body.
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manofsteele2003
New member
285= width in mm and 75= the percentage of the width is the height. So 75% of 285 is the sidewall height. That's why when you go wider the sidewall is taller.
wfo9
New member
Each tire mfg gives a recommended min and max rim width for each tire they sell. Many shops will only mount the tire if your rim is within that specified range. So look up the specs on the tire you want and go with that. Is it different for each specific tire, but 7.5 is probably the min for a 285/75 17.
weeeee
New member
There are plenty of people running 285+ on the stock TRDP and SR5 wheels. There's even someone running the wider 12.5" General Red Letters. The question is how far you are willing to push the manufacturers recommended wheel widths. The most adverse effect you will encounter is poor/uneven tire wear.
I'm currently running a 34x10.5 on my TRDP which is taller than a 285 but close to a factory tire in tread width.
I'm currently running a 34x10.5 on my TRDP which is taller than a 285 but close to a factory tire in tread width.
