Ford's answers to the NHTSA 6.7 Investigation

NinerBikes wrote:


Having done a little bit of failure analysis with fasteners, it is extremes that usually cause failures... be it extremely high rpms, extreme changes in load, from full throttle applications at high rpms to the ECM lifting the throttle to release load in 70-150 microseconds so the transmission can shift, to extreme heat, always something that continues to exceed the design limits until some sort of minor failure, stress cracks, peening, hammering, work hardening load, galling, whatever, is exceeded, then the crumbling begins towards immediate failure shortly thereafter.

I would hazard a guess that this pump design, valving, rail, injectors, bleed off valves and or pressure sensors, perhaps even the programming of the ECM, does not handle extreme changes in throttle settings very well, from full throttle, full 2000 bar pressure, to being shut off, be it to shift, to slow down for a red light, slow down for traffic conditions, etc. My observations in big city driving is that US drivers do not drive very smooth at all, more like a bunch of drones, racing from red light to red light, wasting fuel, brakes, inertia in heavy traffic, cutting others off, squeezing in, tailgating, basically combat race driving on public streets. This type of driving is brutal on equipment, motors, drive trains... everything. Motors run at steady state, on open highways or interstates, make much more mileage between failure of mechanical parts.