GC tires - 225/75 vs 245/70 (R16)
#121
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Re: GC tires - 225/75 vs 245/70 (R16)
"Lon" <lon.stowell@comcast.net> wrote in message
news:avOdnXMwWLiG1b_eRVn-iA@comcast.com...
>J Strickland proclaimed:
>> Not if the change was from 225 to 235. These numbers represent the tread
>> width in mm, and 10mm is the functional equivelent of 3/8".
>>
>> Now, there is some misunderstanding (at least on my part) of just exactly
>> where they measure 225 or 235, and the actual tread blocks being square
>> on one tire and rounded off on the other might play a role in your
>> perception of an inch difference, but the actual difference is 10mm. Your
>> point being that you are looking at the tread patch on the ground is not
>> lost on me ...
>>
> The 225/235 is the sectional width, not the tread width. And now that
> you mention it, I can't remember where they measure it either... and
> the actual size is always rounded off anyway. Unless the tires
> involved have exactly the same tread compounds and patterns,
> comparing traction based on section [or tread] width is a waste of
> time, as it really depends more on the pattern and compounds.
Agreed, especially when the discussion is the difference in 225 and 235.
There can easily be other factors when the difference is, as Mike points
out, a 11.50 and a 9.50, or whatever. But the OP asked about the differences
in the performance of a 225 vs. a 235, and I don't think he will notice
much, if anything, unless he also changes the tread pattern and/or rubber
compound.
#122
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Re: GC tires - 225/75 vs 245/70 (R16)
"Billy Ray" <Billy_Ray@SPAMfuse.net> wrote in message
news:524c4$43259b52$d8449845$22291@FUSE.NET...
> For emergency use it will be fine.
>
> If you intend to buy 3 new tires and use the Wrangler ST as the 4th
you need
> to buy 3 more Wrangler STs.
>
> You don't want to mix tires of vastly different qualities
> --
>
no - intent is keeping new full size spare intact as spare
and putting all 4 new tires on the beast -
#123
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Re: GC tires - 225/75 vs 245/70 (R16)
"Billy Ray" <Billy_Ray@SPAMfuse.net> wrote in message
news:524c4$43259b52$d8449845$22291@FUSE.NET...
> For emergency use it will be fine.
>
> If you intend to buy 3 new tires and use the Wrangler ST as the 4th
you need
> to buy 3 more Wrangler STs.
>
> You don't want to mix tires of vastly different qualities
> --
>
no - intent is keeping new full size spare intact as spare
and putting all 4 new tires on the beast -
#124
Guest
Posts: n/a
Re: GC tires - 225/75 vs 245/70 (R16)
"Billy Ray" <Billy_Ray@SPAMfuse.net> wrote in message
news:524c4$43259b52$d8449845$22291@FUSE.NET...
> For emergency use it will be fine.
>
> If you intend to buy 3 new tires and use the Wrangler ST as the 4th
you need
> to buy 3 more Wrangler STs.
>
> You don't want to mix tires of vastly different qualities
> --
>
no - intent is keeping new full size spare intact as spare
and putting all 4 new tires on the beast -
#125
Guest
Posts: n/a
Re: GC tires - 225/75 vs 245/70 (R16)
"Billy Ray" <Billy_Ray@SPAMfuse.net> wrote in message
news:524c4$43259b52$d8449845$22291@FUSE.NET...
> For emergency use it will be fine.
>
> If you intend to buy 3 new tires and use the Wrangler ST as the 4th
you need
> to buy 3 more Wrangler STs.
>
> You don't want to mix tires of vastly different qualities
> --
>
no - intent is keeping new full size spare intact as spare
and putting all 4 new tires on the beast -
#126
Guest
Posts: n/a
Re: GC tires - 225/75 vs 245/70 (R16)
"Billy Ray" <Billy_Ray@SPAMfuse.net> wrote in message
news:9a82f$4321d782$d8449845$28365@FUSE.NET...
> You are somewhat correct as far as it goes. 75% of 225 mm is 168.75 mm
> and 70% of 245 mm is 171.5 mm for a difference of 2.75 mm
>
> There is a difference in the lower profile tires which hasn't been
> mentioned in sidewall stiffness (roll) which affects handling on-road but
> as I mentioned before the suspension of a Grand cannot really utilize the
> benefit due to its high center of gravity.
>
But there is no "lower profile" in these two tires. The OP was talking aobut
the standard 225 and a possible change to a 235, by the way - not a 245. But
the point remains the same whether a 235 or 245, the rim diameter is the
same, and the sidewall is only changing a couple of milimeters. When the rim
changes from a 15" to a 16 or 17, and the sidewalls get significantly
narrower to maintain the same overall diameter, then we have the discussion
you are talking about. But the OP is retaining the same rims, and the tire
size is 225/75 or 235/70, and the difference in the diameter on these tires
does not present the sidewall stiffness issues that you are bringing up.
> The poster's original question was, I believe, would there be any
> interference problem in his WJ. My answer then and now is No, there is no
> problem as both are listed in the manual and on the door placard as
> alternates.
>
My answer to him is also, no. There is no reason in the world he can't go
from a 225/75 to a 235/70.
> FWIW I recently put 225-75X16s on my WJ but my original thought was to get
> the 245-70-16s
>
The 245 vs. the 225 could potentially cause issues with the fenders and/or
the undercarriage, but I doubt it.
#127
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Posts: n/a
Re: GC tires - 225/75 vs 245/70 (R16)
"Billy Ray" <Billy_Ray@SPAMfuse.net> wrote in message
news:9a82f$4321d782$d8449845$28365@FUSE.NET...
> You are somewhat correct as far as it goes. 75% of 225 mm is 168.75 mm
> and 70% of 245 mm is 171.5 mm for a difference of 2.75 mm
>
> There is a difference in the lower profile tires which hasn't been
> mentioned in sidewall stiffness (roll) which affects handling on-road but
> as I mentioned before the suspension of a Grand cannot really utilize the
> benefit due to its high center of gravity.
>
But there is no "lower profile" in these two tires. The OP was talking aobut
the standard 225 and a possible change to a 235, by the way - not a 245. But
the point remains the same whether a 235 or 245, the rim diameter is the
same, and the sidewall is only changing a couple of milimeters. When the rim
changes from a 15" to a 16 or 17, and the sidewalls get significantly
narrower to maintain the same overall diameter, then we have the discussion
you are talking about. But the OP is retaining the same rims, and the tire
size is 225/75 or 235/70, and the difference in the diameter on these tires
does not present the sidewall stiffness issues that you are bringing up.
> The poster's original question was, I believe, would there be any
> interference problem in his WJ. My answer then and now is No, there is no
> problem as both are listed in the manual and on the door placard as
> alternates.
>
My answer to him is also, no. There is no reason in the world he can't go
from a 225/75 to a 235/70.
> FWIW I recently put 225-75X16s on my WJ but my original thought was to get
> the 245-70-16s
>
The 245 vs. the 225 could potentially cause issues with the fenders and/or
the undercarriage, but I doubt it.
#128
Guest
Posts: n/a
Re: GC tires - 225/75 vs 245/70 (R16)
"Billy Ray" <Billy_Ray@SPAMfuse.net> wrote in message
news:9a82f$4321d782$d8449845$28365@FUSE.NET...
> You are somewhat correct as far as it goes. 75% of 225 mm is 168.75 mm
> and 70% of 245 mm is 171.5 mm for a difference of 2.75 mm
>
> There is a difference in the lower profile tires which hasn't been
> mentioned in sidewall stiffness (roll) which affects handling on-road but
> as I mentioned before the suspension of a Grand cannot really utilize the
> benefit due to its high center of gravity.
>
But there is no "lower profile" in these two tires. The OP was talking aobut
the standard 225 and a possible change to a 235, by the way - not a 245. But
the point remains the same whether a 235 or 245, the rim diameter is the
same, and the sidewall is only changing a couple of milimeters. When the rim
changes from a 15" to a 16 or 17, and the sidewalls get significantly
narrower to maintain the same overall diameter, then we have the discussion
you are talking about. But the OP is retaining the same rims, and the tire
size is 225/75 or 235/70, and the difference in the diameter on these tires
does not present the sidewall stiffness issues that you are bringing up.
> The poster's original question was, I believe, would there be any
> interference problem in his WJ. My answer then and now is No, there is no
> problem as both are listed in the manual and on the door placard as
> alternates.
>
My answer to him is also, no. There is no reason in the world he can't go
from a 225/75 to a 235/70.
> FWIW I recently put 225-75X16s on my WJ but my original thought was to get
> the 245-70-16s
>
The 245 vs. the 225 could potentially cause issues with the fenders and/or
the undercarriage, but I doubt it.
#129
Guest
Posts: n/a
Re: GC tires - 225/75 vs 245/70 (R16)
"Billy Ray" <Billy_Ray@SPAMfuse.net> wrote in message
news:9a82f$4321d782$d8449845$28365@FUSE.NET...
> You are somewhat correct as far as it goes. 75% of 225 mm is 168.75 mm
> and 70% of 245 mm is 171.5 mm for a difference of 2.75 mm
>
> There is a difference in the lower profile tires which hasn't been
> mentioned in sidewall stiffness (roll) which affects handling on-road but
> as I mentioned before the suspension of a Grand cannot really utilize the
> benefit due to its high center of gravity.
>
But there is no "lower profile" in these two tires. The OP was talking aobut
the standard 225 and a possible change to a 235, by the way - not a 245. But
the point remains the same whether a 235 or 245, the rim diameter is the
same, and the sidewall is only changing a couple of milimeters. When the rim
changes from a 15" to a 16 or 17, and the sidewalls get significantly
narrower to maintain the same overall diameter, then we have the discussion
you are talking about. But the OP is retaining the same rims, and the tire
size is 225/75 or 235/70, and the difference in the diameter on these tires
does not present the sidewall stiffness issues that you are bringing up.
> The poster's original question was, I believe, would there be any
> interference problem in his WJ. My answer then and now is No, there is no
> problem as both are listed in the manual and on the door placard as
> alternates.
>
My answer to him is also, no. There is no reason in the world he can't go
from a 225/75 to a 235/70.
> FWIW I recently put 225-75X16s on my WJ but my original thought was to get
> the 245-70-16s
>
The 245 vs. the 225 could potentially cause issues with the fenders and/or
the undercarriage, but I doubt it.
#130
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Posts: n/a
Re: GC tires - 225/75 vs 245/70 (R16)
"Phil Schuman" <pschuman_NO_SPAM_ME@interserv.com> wrote in message
news:fqgVe.173$jS.152@newssvr30.news.prodigy.com.. .
>
> "Phil Schuman" <pschuman_NO_SPAM_ME@interserv.com> wrote in message
> news:3VMTe.684$au2.349@newssvr17.news.prodigy.com. ..
>> The Grand Cherokee OE tires are the Wrangler ST with 225/75R16 -
>> I was wondering if the 245/70R16 sizes cause any probs
>> with speedometer or front turning clearance under the cowling
>> or any other considerations on going from the 75 to the 70 ?
>> It seems like the overall outside tire diameter is the same, but ??
>>
> One last nagging question on the slight sizing difference -
> What about the full size spare I have - 225/75R16 -
> Any major concerns on running 3 tires of the alt size - 245/70R16
> along with the spare that is 225/75R16 -
>
It would be a very bad thing to run 3 tires of one size, and a spare of
another. It would be okay to run like this on the front axle to get off the
freeway and to the next tire store, and the rear axle would behave as if it
was going around a corner and won't like it but it would not explode getting
you off of the freeway -- but could easily be damaged going more than a few
miles, I'm thinking the range of about 50 miles would be the limit.
You are correct though, the difference is under a quarter inch, and this
ought not be a huge problem. Having said that, my BMW had 205/60x15's on the
ground, and a 225/55x15 in the trunk. I had a blow out on the rear and the
spare caused the limited slip to make lots of noise. The difference in the
tire size is only .06", and this is only about 25% of the difference you'll
be having.
> The diameters calc out to a difference of .216"
> 225/75R16 = 29.287
> 245/70R16 = 29.503
>
>
>