Problem $1.$ Solve problem $1\mathrm{.}69$ of the textbook. How steep a grade can be climbed by the automobile in

Sample Problem $1\mathrm{.}3($with a $2\mathrm{.}64$ axle ratio$)$ while maintaining a constant $55mph$ :

a$)$ With transmission in direct drive?

b$)$ With a transmission reduction ratio of $1\mathrm{.}6?$

SAMPLE PROBLEM $1\mathrm{.}3$ Automotive Performance Analysis

Figure $1\mathrm{.}7$ shows a representative engine power requirement curve for constant speed, level road operation of a $4000-$lb

automobile. Figure $1\mathrm{.}8$ shows the wide$-$open$-$throttle horsepower curve of its$--$

$350i{n}^{3}V-8$ engine. Figure $1\mathrm{.}9$ gives specific fuel consumption curves for the engine for the vehicle shown in Figure $1\mathrm{.}10.$

The extreme right$-$hand point of each curve represents wide$-$open$-$throttle operation. The rolling radius of the wheels

varies a little with speed, but can be taken as $13$ in$.$ The transmission provides direct drive in high gear.