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P 205 / 50 R 17 89 Y M+S DOT "UYZEDBC1301"
Click on the numbers to see that each stands for:
P 205 / 50 R 17 89 Y M+S DOT "UYZEDBC1301"
P = Passenger vehicle type
P = Passenger Car designed to meet North American passenger car standards
LT = Light Trucks
T = Truck
the lack of a preceding letter means a tire designed for European standards
Nominal Width of Tire
205 = 205 mm wide, sidewall to sidewall nominal width of tire, in millimeters
not exactly the same as tread width, but close
to convert to inches, divide by 25.4
Tire Aspect Ratio
50 = 50% tire aspect ratio
the sidewall height, expressed as a percentage of the tread width
in this case, 50% of 205mm = 102mm
• higher aspect ratios provide a softer ride
• lower aspect ratios have a faster response and a rougher ride
aspect ratio qualities
70-75 low cost tire, less precise turn-in, lower stability at high speeds
65 common profile, compromise between precision and comfort
60 slightly more precise and harder riding
50-55 high performance, increased precision and grip
45 and lower high performance, wears quickly
R = Radial tire type
R = Radial - the cords of the belting are perpendicular to the tire tread
D = Diagonal -
B = Bias belted
17 = 17" wheel diameter, in inches
89 = load index
a measure of the load a properly inflated tire can carry
65 = 639 lbs.
66 = 661 lbs.
88 = 1235 lbs.
89 = 1279 lbs.
90 = 1323 lbs.
91 = 1356 lbs.
92 = 1389 lbs.
93 = 1433 lbs.
94 = 1477 lbs.
149 = 7165 lbs.
150 = 7385 lbs.
Y = Y speed rated speed rating
Speed Ratings - sustained speed, in miles per hour
B = 50 km/h = 31 mph
C = 60 km/h = 37 mph
D = 65 km/h = 40 mph
E = 70 km/h = 43 mph
F = 80 km/h = 50 mph
G = 90 km/h = 56 mph
J = 100 km/h = 62 mph
K = 110 km/h = 68 mph
L = 120 km/h = 75 mph
M = 130 km/h = 81 mph
N = 140 km/h = 87 mph
P = 150 km/h = 93 mph
Q = 160 km/h = 99 mph
R = 170 km/h = 106 mph
S = 180 km/h = 112 mph
T = 190 km/h = 118 mph
U = 200 km/h = 124 mph
H = 210 km/h = 130 mph
V = 240 km/h = 149 mph
"Ultra-High Performance Tires":
W = 270 km/h = 169 mph
Y = 300 km/h = 188 mph
Z = ZR = >240 km/h = >150 mph
M+S = Mud + Snow
DOT Tire Specification
DOT "UYZEDBC1301" = U.S. DOT (Department of Transportation) Tire Specification
this code can be used in the event of a tire recall
UY = Plant Code
ZE = Tire Size
DBC = Compound Structure Code optional
13 = the week manufactured (13th week of the year)
01 = the year manufactured (01 = 2001) don't purchase tires that are more than a couple of years old
Traction and Temperature Ratings
Traction a measure of wet stopping ability
AA = best
C = worst
Temperature resistance to high temperatures
A = best
C = worst
A tire rated 800 should last twice as long as a tire rated 400.
A tire rated 400 should last twice as long as a tire rated 200.
Winter tires do not carry a Tread-Wear Rating.
According to the guidelines of the SCCA (Sports Car Club of America), tires with a treadware
rating of 140 or greater are considered "street" tires. Softer tires are considered "race" tires.
1966 PORSCHE 912
The Porsche 912 uses equal size tires front and rear
going to 185/65R15 throws speedometer off 10 mph
912 with original 5.5x14 wheels is running 205/60HR14 all around
my SWB 912 loves 185/65
195/65 work on swb 912s
on 4.5x15 wheels => 185/70VR15 Yoko A321 tires ('67 912)
a 1966 with 6" Fuchs wheels:
185/65/15 => no rub
185/70/15 => rub
as far as wheel height is concerned, 195/60/15 = 185/65/15
a 185 on a 4.5" wheel is pushing it, 185 better off using a 5.5" wheel
195 is top limit on 5.5" wheels
6" rims are good for 185->205
a 205 tire should be on a 7" rim
195/65x15 works with 5.5" wheels on a 1967
Dunlop SP A2 185/65R15 on 4.5" wheels on a 1965 gets a slight inner tire rub on full turns
a 215 is one inch wider than a 185/70
a 215 is 1/5" wider than a 205/60
do not use 215 in front - it will touch fender during turns
205x60 will work on 5.5" rims & will clear narrow-bodied 912
195x65 closer in size and appearance to original, try Tire Rack
Hoosier Vintage TD 5.50x15 tire equivalent of 185x70 period correct Bias Ply (non-radial)
illegal for street use (not DOT approved) = default race tire the 356 racers use
on a 1966 912 with 6" Fuchs:
185/65/15 doesn't rub
tire height & wheel diameter
185/70/15 => 70% of 185mm = 129.5mm tire height /// 640mm = 25.2" wheel diameter
195/65/15 => 65% of 195mm = 126.75mm tire height /// 635mm = 25" wheel diameter
185/65/15 => 65% of 185mm = 120.25mm tire height /// 622mm = 24.5" wheel diameter
195/60/15 => 60% of 195mm = 117mm tire height /// 615mm = 24.2" wheel diameter
real life examples:
Hoosier Vintage 5.50x15 => 24.7" diameter / 7.7" section width (627mm / 196mm) [4.5"-7" rim]
Michelin XZX 165 SR 15 => 25.4" diameter (646mm / 167mm)
B.F. Goodrich 165 R 15 => 25.4" diameter (645mm)
165SR15 B.F.Goodrich W/W 635mm diameter / 161mm section width
165SR15 Dayton W/W 635mm / 161mm
165SR15 Michelin XZX 646mm / 167mm
165SR15 Firestone F560 646mm / 167mm
165HR15 Vredestein Classic 645mm / 165mm (25.4" / 6.5") my car originally came with 165HR15 tires
165HR15 Michelin XAS 646mm / 167mm (25.4" / 6.6") my car originally came with 165HR15 tires
165SR15 Vredestein 645mm / 165mm
180HR15 Michelin XAS 680mm / 175mm
185/70HR15 Avon CR6ZZ 635mm / 187mm
185/70VR15 Michelin XWX 641mm / 189mm
185/70HR15 Vredestein Classic 650mm / 188mm
Michelin XWX 185/70 VR 15 => 25.5" diameter
B.F. Goodrich P185/70 R 15 => 25.2" diameter
Pirelli P6000 195/65 ZR 15 => 25.1" diameter (638mm) 19lbs. $113.
Hoosier P185/65 R 15 => 24.2" diameter / 7.6" cross section (615mm / 193mm)
a treadware rating of 140 (or 200?) is required to avoid penalization in SCCA solo
Hoosier Vintage TD 5.50-15 dimensions:
tread width 6.5"
measured rim 4.5"
TIRE OPTIONS for 4.5"x15" rims:
- Sprint Classic 165 HR 15 86H
- Sprint 165 HR 15 $89
- XZX 165 SR 15 $137 diameter 25.40 / cross section 6.40
- XWX 185/70 VR 15 $301 diameter 25.50 / cross section 7.70
- Spirit Classic
- Sprint +
closest to 165/15 => 185/70x15 & 195/65x15
recommended => 185/70x15 & 185/65x15
TIRE OPTIONS for 5.5"x15" rims:
- Pirelli P6000 $113 diameter 25.10 / section width 8.0 / 19lbs.
factors involved in how a car handles
1. grip level - how the car holds the road
2. steady-state balance - mid-corner balance
3. transitional balance - corner enty and exit balance
oversteer - the rear end breaks loose before the front end
understeer - the front end breaks loose before the rear end
a zip tie-on on the shock shaft can tell you how much suspension travel you're getting
1. grip is controlled by
2. steady-state balance is controlled by
PV = nRT
P = Pressure
T = Temperature
MOTOR VEHICLE ENDORSEMENT
The definition of "motor vehicle" is replaced with the following:
"motor vehicle", when used in Section II of this policy,
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"Recreational vehicle", means a motorized vehicle
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