Let’s see. I’ve got a 74, an 85, two 87s, and three 92s. And none of them have the second generation onboard diagnostics. I’m thinking there’s a bunch of “clunkers” out there, they don’t know about.
Did I mention the last new vehicle I bought was a 92? Been buying used ever since. I’m currently looking for a pre-86 Ford with a 300-6 for a natural gas conversion. If you guessed that’s not going to be filled from a commercial filling station, you’re right!
OBD-II does not inherently record mileage. It does, however, greatly simplify diagnosing problems.