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05-30-2001, 10:09 PM | #1 |
Account Suspended
Join Date: May 2000
Location: IL
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tires math formula
Whats the correct formula for converting P metric tire size to diameter in inches ?
Im trying to figure out what P metric size 15" tires are around 31" tall, but are 60, 55, or 50 series. I want a couple 15" street tires somewhere around 8 or 9 inches wide and about 30 inches tall. maybe 295/60/15 ? Or am I way off ? ------------------ -'77 Electra 403/TH350 -'76 GMC C-1500 Sierra Classic 350 4-bolt/TH350, 3.40 ratio -'68 C-10 chassis -'72 K-5 chassis http://communities.msn.com/RandyR72K5 Randy Lincoln, IL Flying wrenches are cool only when you are the person throwing them.... r72k5@hotmail.com |
05-31-2001, 12:28 AM | #2 |
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Join Date: Jan 2000
Location: ca
Posts: 1,110
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check with the manufacturer, bfg gives a ton of specs on their site www.bfgoodrichtires.com
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68 short step, 406/700r4, 9" w/discs. |
05-31-2001, 02:52 PM | #3 |
High Speed, Low Drag.....
Join Date: Mar 2000
Location: Madison, SD, USA
Posts: 358
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Fast -
Tire size is a little wierd. The 50-60-70-75 numbers in the tire size are aspect ratios, or what percentage of the tire width the sidewall height is. On a tire sized as 255/70R15 255 would be the width of the tire in millimeters, 70 would mean the sidewall height is 70% of the tire width and r15 is the size of the rim the tire is to be mounted on. To convert millimeters to inches, divide the number by 25.4 - 255/25.4= 10 inches. 10 inches * 70%= 7 inch sidewall height. 7 inch sidewall height * 2 = 14 inches + 15 inch rim diameter = 29 inches of tire height.
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'72 Chevy lwb fleetside "Winners never quit, and Quitters never win......but those who never win AND never quit are idiots." |
05-31-2001, 03:46 PM | #4 |
Led Sled! Discs R 4 ME!
Join Date: Jan 2001
Location: Toms River, NJ, USA (Transplanted Hoosier)
Posts: 7,327
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Another example..
Ex: 225/45/17 your tire 225(width)X 45%(profile)= 101.25 x 2 = 202.50 / 25.40 (for metric conversion) = 7.97" + the 17"(rim size) = 24.97" for total size So basically substitute the letters in bold with your new tire sizes, hope this helps ------------------ Toms River NJ (Transplanted Hoosier) 71 custom 20 - 307 3onthetree-bone stock *sold* 56 working Street rod (under construction) 91 S10, 4.3L-700R4 92 Olds 98 land yhat..(wifes) 20 ft. long hole in water in which i throw my money The number one cause of computer problems is computer solutions. |
06-02-2001, 05:01 PM | #5 |
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Join Date: May 2000
Location: IL
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Neat! Thanks
------------------ -'77 Electra 403/TH350 -'76 GMC C-1500 Sierra Classic 350 4-bolt/TH350, 3.40 ratio -'68 C-10 chassis -'72 K-5 chassis http://communities.msn.com/RandyR72K5 Randy Lincoln, IL Flying wrenches are cool only when you are the person throwing them.... r72k5@hotmail.com |
06-02-2001, 09:02 PM | #6 | |
Bloo
Join Date: Feb 2001
Location: Barren County Kentucky
Posts: 6,283
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theres also another formula. give me a while to find my four wheeler book that has it and i will tell you
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ASE Master Certified-GM Trained-Mechanic 1968 Chevy C30 157" WB Wrecker 1969 Chevy CST/10 SWB 1971 Chevy Custom/10 (first truck) 350, NV3500 5 speed 1971 Chevy K20 Custom Camper 4x4 350 TBI, SM465/NP205 1974 Chevy Custom Deluxe/10 1979 Chevy Custom Deluxe K10 farm truck beater 1989 Chevy K2500 Quote:
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