Ford Pinto
Offered with an inline-4 engine and bucket seats the Pinto's mechanical design was conventional, with unibody construction, a longitudinally mounted engine in front driving the rear wheels through either a manual or automatic transmission and live axle rear end. Suspension was by unequal-length control arms with front coil springs; the live rear axle was suspended on leaf springs. The rack and pinion steering had optional power assist, as did the brakes.
Ford Pinto
The Pinto's design positioned its fuel tank between the rear axle and the rear bumper, a standard practice in US subcompact cars at the time. The Pinto's vulnerability to fuel leakage and fire in a rear-end collision was exacerbated by reduced rear "crush space", a lack of structural reinforcement in the rear, and an "essentially ornamental" rear bumper (though similar to other manufacturers). Crash testing, conducted in 1970 with modified Ford Mavericks, as part of a response to NHTSA proposed regulations, demonstrated vulnerability at fairly low crash speeds. Design changes were made, but post launch tests showed similar results. These tests were conducted to develop crash testing standards rather than specifically investigating fuel system integrity. Though Ford engineers were not pleased with the car's performance, no reports of the time indicate particular concern.
Ford also tested several different vehicle modifications which could improve rear impact performance. However, the engineer's occupational caution and aversion to "unproven" solutions as well as a view that the crash test results were inconclusive resulted in the use of a conventional fuel tank design and placement. The use of an above the axle tank location was considered safer by some (but not all) at Ford. This placement was not a viable option for the hatchback and station wagon body styles.