How do you figure tire height?
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Member
Joined: Aug 2003
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From: Ozarks/Arkansas
How do you figure tire height?
I was looking at 1010tires.com, a URL that I got from another post here...
When doing a search for tires to fit my Expy they listed 16" tires at P255/70R16. I have the 17" wheel so I upsized and it listed what is on my truck the P265/70R17.
How do you figure the overall tire size for each of these? I am looking to see what the difference would be if I went to 16" wheels and tires.
When doing a search for tires to fit my Expy they listed 16" tires at P255/70R16. I have the 17" wheel so I upsized and it listed what is on my truck the P265/70R17.
How do you figure the overall tire size for each of these? I am looking to see what the difference would be if I went to 16" wheels and tires.
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http://www.ring-pinion.com/calculato...latorsind.html
Click on this, then on "tire height" on the left and insert numbers.
Click on this, then on "tire height" on the left and insert numbers.
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Joined: Mar 2001
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From: Avoca,Mi,USA
Easy Here's how
265/75 -16
265 MM is the tread width
75 is the percent of height of sidewall to tread width
16 INCH rim diameter
So 265 divided by 25.4 (converts metric to english) = the tread width.. 10.433 Okay stay with me...
Times .75 (75%) = sidewall height (7.824) X 2 for both sidewalls the top and the bottom of the tire. =15.649..... Stay with me now....
Plus 16 inches (rim diameter at the bead) =31.649
Tah Daaa that's you tire height 31.65
Easy Huh!!
265/75 -16
265 MM is the tread width
75 is the percent of height of sidewall to tread width
16 INCH rim diameter
So 265 divided by 25.4 (converts metric to english) = the tread width.. 10.433 Okay stay with me...
Times .75 (75%) = sidewall height (7.824) X 2 for both sidewalls the top and the bottom of the tire. =15.649..... Stay with me now....
Plus 16 inches (rim diameter at the bead) =31.649
Tah Daaa that's you tire height 31.65
Easy Huh!!
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Joined: Aug 2003
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From: Ozarks/Arkansas
Okay. That is easy, both the calculator and the math.
Thank you all for your replies.
Here is my delimma. I have an Expy that has 17" wheels stock tire size is 265/70R17. In the manual it says that with 16" wheels my truck can 500 more lbs of trailer weight. Is this because of tire size or because of wheel weight or what?
I was thinking that when it came time to get new tires that I would just get smaller tires and put them on the 17" wheel.
Would this compensate for the difference or am I missing something?
Thank you.
Thank you all for your replies.
Here is my delimma. I have an Expy that has 17" wheels stock tire size is 265/70R17. In the manual it says that with 16" wheels my truck can 500 more lbs of trailer weight. Is this because of tire size or because of wheel weight or what?
I was thinking that when it came time to get new tires that I would just get smaller tires and put them on the 17" wheel.
Would this compensate for the difference or am I missing something?
Thank you.
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Joined: Oct 2002
Posts: 5,358
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From: Commerce Twp, MI
I am 95% confident the higher tow rating for 16" rims has to do with the shorter effective gearing. The largest 16" tire availible for Expy's was at least 5% smaller in circumfrence than 265/70R17. That's like changing the gear ration from 3.55 to 3.73, thus giving you a better torque multiplier.
Replacing your tires with something a little smaller is a good idea if you wnat better towing response, but if you are near the Ford rated limits, you should think about upgrading the tow vehicle.
Replacing your tires with something a little smaller is a good idea if you wnat better towing response, but if you are near the Ford rated limits, you should think about upgrading the tow vehicle.
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Joined: Mar 2004
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From: NS, Canada
Upgrading tow rig
Originally posted by APT
I am 95% confident the higher tow rating for 16" rims has to do with the shorter effective gearing. The largest 16" tire availible for Expy's was at least 5% smaller in circumfrence than 265/70R17. That's like changing the gear ration from 3.55 to 3.73, thus giving you a better torque multiplier.
Replacing your tires with something a little smaller is a good idea if you wnat better towing response, but if you are near the Ford rated limits, you should think about upgrading the tow vehicle.
I am 95% confident the higher tow rating for 16" rims has to do with the shorter effective gearing. The largest 16" tire availible for Expy's was at least 5% smaller in circumfrence than 265/70R17. That's like changing the gear ration from 3.55 to 3.73, thus giving you a better torque multiplier.
Replacing your tires with something a little smaller is a good idea if you wnat better towing response, but if you are near the Ford rated limits, you should think about upgrading the tow vehicle.