9. Thermal efficiency of a spark ignition engine at full load usually is in the range
A. 30 to 35 percent
B. 70 to 90 percent
C. 10 to 25 percent
D. 50 to 70 percent
9. Thermal efficiency of a spark ignition engine at full load usually is in the range
A. 30 to 35 percent
B. 70 to 90 percent
C. 10 to 25 percent
D. 50 to 70 percent