Some things to keep in mind for airing down. A pressure that you may read works for one tire size won't work for all tires of the same size, and the pressures that work will vary by the tire design and wheel combination too.
The tire's Load Range has the biggest effect. A Load Range E tire is stiffer/stronger than a Load Range D which is stiffer/stronger than Load Range C which is the appropriate Load Range for our Wrangler TJs. The stiffer the tire, the more it needs to be aired down to get the same flexibility and size of footprint. A stiffer stronger tire is simply not as flexible so to get the tire to flex/conform to obstacles a higher Load Range tire has to be aired down further than a lower Load Range tire Plus the design of the tire plus its bead strength will also affect how well or how easily it can stay seated when aired down.
Some say they have aired down to some particular PSI and lost a bead while others have no problems going to an even lower air pressure and never lose a bead. How can that be? That is due to the design of the tire, its stiffness/load rating, and even the wheel's width. A 33x12.50 tire mounted on a 15x8 wheel will be able to stay seated at a lower pressure than the same exact tire can if mounted on a wider 15x10 or 15x12 wheel. The wider the wheel the more air pressure the tire requires to keep its beads seated against the two wheel mounting points that are further apart. So if you're running a 15x10 wheel, a 33x12.50 tire will not be able to be aired down as far as the same tire could be on a 15x8 wheel. And if you were running a narrower 33x10.50 tire it's even more important that you avoid wider wheel widths like 15x10 or (especially) 15x12.
Remember that a tire's advertised width is only its widest width half-way up the sidewall which can be up to several inches wider than its mounting beads. A 33x10.50 tire, for example, will probably have beads that are only 7 or 8" apart which is why you should run a 15x7 or 15x8 wheel for a 10.5" wide tire. Trying to run a 33x10.50 tire on a 15x10 wheel, for example, would result in the tire being forced to position its mounting beads much further apart than they were designed for. So never think that you're supposed to buy wheels the same width as the tire's advertised width. It can work for those seeking that low-rider look for the street but it won't work for the trail as tires that are mounted on wheels that are wider than optimal will cause the tire to unseat very easily.
Just keep in mind that there's no hard-fast rule for what tire pressure is acceptable on any given size tire. It varies, again, by lots of variables so listening to one guy telling you what works for him may or may not work for you.
And keep in mind too that airing down properly can make the difference between a difficult vs. a fun day on the trail.
The tire's Load Range has the biggest effect. A Load Range E tire is stiffer/stronger than a Load Range D which is stiffer/stronger than Load Range C which is the appropriate Load Range for our Wrangler TJs. The stiffer the tire, the more it needs to be aired down to get the same flexibility and size of footprint. A stiffer stronger tire is simply not as flexible so to get the tire to flex/conform to obstacles a higher Load Range tire has to be aired down further than a lower Load Range tire Plus the design of the tire plus its bead strength will also affect how well or how easily it can stay seated when aired down.
Some say they have aired down to some particular PSI and lost a bead while others have no problems going to an even lower air pressure and never lose a bead. How can that be? That is due to the design of the tire, its stiffness/load rating, and even the wheel's width. A 33x12.50 tire mounted on a 15x8 wheel will be able to stay seated at a lower pressure than the same exact tire can if mounted on a wider 15x10 or 15x12 wheel. The wider the wheel the more air pressure the tire requires to keep its beads seated against the two wheel mounting points that are further apart. So if you're running a 15x10 wheel, a 33x12.50 tire will not be able to be aired down as far as the same tire could be on a 15x8 wheel. And if you were running a narrower 33x10.50 tire it's even more important that you avoid wider wheel widths like 15x10 or (especially) 15x12.
Remember that a tire's advertised width is only its widest width half-way up the sidewall which can be up to several inches wider than its mounting beads. A 33x10.50 tire, for example, will probably have beads that are only 7 or 8" apart which is why you should run a 15x7 or 15x8 wheel for a 10.5" wide tire. Trying to run a 33x10.50 tire on a 15x10 wheel, for example, would result in the tire being forced to position its mounting beads much further apart than they were designed for. So never think that you're supposed to buy wheels the same width as the tire's advertised width. It can work for those seeking that low-rider look for the street but it won't work for the trail as tires that are mounted on wheels that are wider than optimal will cause the tire to unseat very easily.
Just keep in mind that there's no hard-fast rule for what tire pressure is acceptable on any given size tire. It varies, again, by lots of variables so listening to one guy telling you what works for him may or may not work for you.
And keep in mind too that airing down properly can make the difference between a difficult vs. a fun day on the trail.
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