BE 150 SS 97

Project #2


Assuming an automobile has the transmission studied in The Gearbox project, a

differential gear ratio of 37:13, and P165/80R13 tires, what is the engine RPM at

65 mph in high gear.

RESULT :

Wheel Radius = 11.7 "

Diameter = 23.4 "

Circumference = 73.5 " = 6.13 '

Car Moves = 65 mi/hr = 95.33 ft/s = 5720 ft/min.

1 sec = 15.56 rev/s = 933.7 rev/min (rpm)

Transmission ratio = 1:1 ; in forth gear

Engine rpm : 37/13 * 933.7 = 2657.52 rev/min (rpm)