Changing Tires Activity
By Alex Wilhelm and Stone Ormand
Factory and replacement
The factory tire information is 20 inch p275/65r20 width 10.8 ar 65%. Height is 7.02 dia 34.04 circum 106.954. New Tire is 18 inch p275/70r18, width 10.8 , ar 70%, height 7.56' da 33.12 circum 104.0
Miles per gallon
The Standard tires Have 14.7 mpg
The New Tries have 14.26 mpg
Chart and "K" ratio
Chart
Old New
Width 10.8in 10.8in
Ar. 65%. 70%
Height 7.02in 7.56in
Dia. 34.0in 33.12in
Cricum 106.9in 104.0in
K ratio 0.97
Our statements
1. If your odometer is reading is 50,000 (miles) you have travails 48500 miles on the new tires
2. If your speedometer reading is 70 your speed is 67.9 miles per hour with the new tires
3. If your mile per gallon with factory tires is 14.7 what is your miles per gallon with the new tires
K Ratio= 0.97