DO NOT BUY TIRES BASED SOLELY ON THE INFORMATION BELOW!
This list is provided for entertainment only.  No warranty is expressed 
or implied as to its accuracy.  Typographical errors are possible.  
Many thanks to Ken Carothers for posting the original table in the 
"Poncho" mailing list.


With 15" Wheels - 60 series tires       
                                  Section        Overall        
Metric    Width         Aspect    Height        Diameter        
Width    (Inches)       Ratio     (Inches)      (Inches)      
195         7.7          60         4.6           24.2 
205         8.1          60         4.8           24.7 
215         8.5          60         5.1           25.2 
225         8.9          60         5.3           25.6 
235         9.3          60         5.6           26.1 
245         9.6          60         5.8           26.6 
255        10.0          60         6.0           27.0 
265        10.4          60         6.3           27.5 
275        10.8          60         6.5           28.0 


With 15" Wheels - 65 series tires       
                                  Section        Overall        
Metric    Width         Aspect    Height        Diameter        
Width    (Inches)       Ratio     (Inches)       (Inches)      
195         7.7          65         5.0           25.0 
205         8.1          65         5.2           25.5 
215         8.5          65         5.5           26.0 
225         8.9          65         5.8           26.5 
235         9.3          65         6.0           27.0 
245         9.6          65         6.3           27.5 
255        10.0          65         6.5           28.1 
265        10.4          65         6.8           28.6 
275        10.8          65         7.0           29.1 


This is from Fred Puhn's "How to Make Your Car Handle."

Tire Size      Design           Section       Overall
Designation    Rim Width        Width         Diameter

F50-14          7.00            10.20           24.32
H50-14          8.00            11.35           25.36
M50-14          9.00            12.55           26.48
N50-14          9.00            12.85           26.84

B50-15          6.00            8.55            23.58
G50-15          7.00            10.35           25.46
H50-15          8.00            11.15           26.06
L50-15          8.00            11.65           26.76
N50-15          9.00            12.65           27.50

D60-14          6.00            8.65            24.44
E60-14          6.50            9.10            24.78
F60-14          7.00            9.55            25.28
G60-14          7.00            9.85            25.80
H60-14          7.00            10.25           26.40
J60-14          7.00            10.45           26.70
L60-14          8.00            11.10           27.20

B60-15          5.50            7.80            24.38
C60-15          6.00            8.25            24.76
E60-15          6.00            8.70            25.50
F60-15          6.50            9.20            25.94
G60-15          7.00            9.70            26.44
H60-15          7.00            10.05           27.08
J60-15          7.00            10.25           27.40
L60-15          7.00            10.50           27.86

C70-14          5.00            7.45            24.90
D70-14          5.50            7.85            25.32
E70-14          5.50            8.05            25.76
F70-14          5.50            8.30            26.24
G70-14          6.00            8.75            26.82
H70-14          6.00            9.10            27.50
J70-14          6.50            9.50            26.44
L70-14          6.50            9.75            28.32

A70-15          4.50            6.60            24.68
C70-15          5.50            7.50            25.58
D70-15          5.50            7.70            26.02
E70-15          6.00            8.10            26.40
F70-15          6.00            8.35            26.92
G70-15          6.00            8.60            27.46
H70-15          6.00            8.95            28.10
J70-15          6.50            9.35            28.44
K70-15          6.50            9.40            28.68
L70-15          6.50            9.60            28.92


Tire Size       Design          Section         Overall
Designation     Rim Width       Width           Diameter

A78-14          4.50            6.45            24.16
B78-14          4.50            6.65            24.70
C78-14          5.00            7.05            25.24
D78-14          5.00            7.35            25.50
E78-14          5.50            7.65            26.00
F78-14          5.50            7.90            26.50
G78-14          6.00            8.35            27.06
H78-14          6.00            8.70            27.76
J78-14          6.00            8.80            28.20

A78-15          4.50            6.35            24.80
B78-15          4.50            6.55            25.38
C78-15          5.00            6.95            25.82
D78-15          5.00            7.15            26.24
E78-15          5.00            7.35            26.64
F78-15          5.50            7.70            27.22
G78-15          5.50            8.05            27.68
H78-15          6.00            8.55            28.36
J78-15          6.00            8.70            28.72
L78-15          6.00            8.85            29.30
M78-15          6.50            9.35            29.68
N78-15          7.00            9.80            30.16