I was thinking if I was designing cars for the big 3, what I’d do is put of those USB sockets in the dashboard, one where you could plug-in a USB memory stick. You know, those things about size of a pack of gum.
Say you buy this car, and take it home. It is running like a top, brand new. So the next morning, you set a benchmark. You plug your memory stick into the socket, start the car, and take a test drive around the neighborhood, then on the freeway to the next exit, and back home. 5 miles total trip say. The car’s computer records all the drivability parameters over that distance, the coolant temp, the air temp, the air flow into the engine, the intake manifold vacuum, the fuel trim, the rpm, etc. And stores all this data as a function of distance driven onto the USB memory stick. You end up with a bunch of graphs of various engine parameters vs distance on the USB stick. Then you put the USB stick in a drawer.
Then say is a few years later your car, all of a sudden, despite having all the routine maintenance, one day it isn’t running well. So you do the same experiment again. Then by comparing the graphs recorded you can immediately see all that is happening inside the engine, and what is different from when it was running like a top when new.
Wouldn’t that help with drivability problem diagnosis?