There is a whole class of engineering analysis called "Failure Mode and Event Analysis" - FMEA for short. FMEA looks at a design and says "if this part jams what happens. What if it fails to move? What if it physically breaks/falls off? What if it outputs nonsense information (if it's a sensor)? What if the wires to this sensor short out, break open, or touch some other wires?" The answers to those questions lead to redundancy in some systems (e.g. the dual hydraulic channels in car brake systems so a single leak won't leave you with no brake fluid) and/or "overdesign" for single threaded systems (e.g. the steering column of your car is WAY WAY stronger than it needs to be to survive any twist force you might apply to the steering
wheel so it should never fatigue/break).
With electronics & computers though it is much harder to analyze every combination. And, the more "stuff" on the vehicle, the more interactions you have to analyze. Now think about analyzing that vehicle 5 to 10 years after it's been sold: how well was it maintained? Maybe that "backup" system is busted but the owner didn't get it fixed... or didn't even know it was busted. How many cars do you see driving down the road with bald tires, a "check engine" light blazing away on the dash, etc. The experience of the design engineers plays a big role in this situation... and being able to review history of past failures (on your cars or the competitor's cars) helps engineers develop scenarios that can catch poor/dangerous designs. "Don't do this... we've seen ice build up on cables like that leading to stuck..." In the aircraft world, airlines report maintenance things they find on aircraft (i.e. "had to replace seal #12345 on fuselage #45206 after x.xxxx flight hours/yyy cycles" back to the manufacturer and to government oversight agencies. This information is shared too - so that trends can be seen. And a statistical database of how often part XYZ fails in service can be determined to see if it's failing more often than the engineers expected. If so, this failure plus some other failure, are more likely than expected and could lead to incidents/accidents.
How much of this occurs in the car world? Nowhere near as much. NHTSA tracks customer complains and fatal accidents reported to it... but it's not like the airplane world where everything is tracked. NHTSA gets more involved if there is a public outcry over something. Parts that fail leading to emissions issues are tracked by law... but not much else is tracked including many things that could affect safety.
So how well does Hyundai design for such failures? Don't know. We've seen posts on these boards from folks having cars that suddenly won't accelerate when something fails... but after a few seconds the engine computer figures out the problem and works around it. Those few seconds though can be hazardous. Sometimes the computer doesn't figure out the problem until after you shut the engine off and restart - yikes. But in general, Hyundai's recent record of reliability says they probably aren't stupid.
Electronics and especially computer controlled stuff are more
precise than mechanical systems. Electronic fuel injection basically became the only way to meet emissions requirements; carburetors just were not precise enough over all conditions (temperature, altitude, varying fuel quality, etc) to meet stringent emissions laws. The computers work by having parts to monitor the exhaust (the oxygen sensor) and use feedback to adjust the air to fuel ratio to get the best emissions... that's a lot of parts "monitoring" the engine rather than just making it "go." Lots of new parts, lots more things to go wrong. How much margin was designed into those parts? Your home computer/laptop probably wouldn't survive the temperatures the engine computer sees in your car - the engine computer has to be designed for much higher temps. But is that design conservative or just enough to survive those temps? If it's conservative, the chances of failure are probably lower (better) than one that is just adequate. Again, recent history indicates Hyundai is doing pretty well.
Personally, I consider electro-mechanical parts the weakest link in cars, airplanes, etc. The more complex the vehicle, the more of these stupid things you'll have. System redundancy/backup algorithms and conservative design are what it takes to minimize the number of problems. If it weren't for the 10 year/100K mile warranty I might not have purchased a Genesis - or any modern vehicle for that matter. I keep my cars for decades because I drive few miles per year... I doubt these electro-mechanical will be 100% problem free for decades. They crap out with time, not mileage too. Will replacements be available 10, 15, 20 years later? Electronic bits are the hardest to find after a long time... mechanical parts are much easier to get for old cars.
mike c.
