Simplify the following text for a Grade 7 native English-speaking person.
Original: The engine was tested at Pikes Peak in Colorado at 14000 f to demonstrate that it could eliminate the power losses usually experienced in internal combustion engines as a result of reduced air pressure and density at high altitude .
Simplified: The engine was tested at Pikes Peak in Colorado at 14000 f. The test was to show that the turbo could add the power airplanes lose at high altitude . Internal combustion engines lose power because at high altitude , the outside air pressure is low .