Good day -
Regarding speedometer errors with various tire sizes,
Triumph_TR4@ridgecrest.ca.us wrote :
>The formula for this is:
>(Original Tire Diameter/Replacement Tire Diameter) x Indicated Speed
>Speed at
>Indicated Approximate
>55 MPH. Tire Diameter (inches)
>55 185/80/15 26.6
>60 185/65/15 24.5
>56 205/70/15 26.3
>59 205/60/15 24.7
>54 215/70/15 26.9
>57 215/65/15 26.0
Shouldn't the figure in parentheses in that formula be reversed?
i.e. : (Replacement Tire Diameter/Original Tire Diameter) x Indicated Speed
Larger diameter means larger circumference means more travel per
revolution; so you're going faster, but the speedo doesn't know it.
Lex Garey, Shelby, NC, '74 TR6
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