Odometer screwy

[BBB]

For the last few years I have been looking forward to my old truck rolling over 400,000 like a badge of honor. Or something it had 315,000 when i bought it years ago.
So the other day here it comes 399,999.9 all excited. Next number 300,000 I stopped and cycled the key! Thought I had been cheated and robbed out of this honor.

Then my next thought was how many times has it done that????

Any ideas whats up with that?

 

[IDIBRONCO]

I've seen it said here that they're designed to do that for some crazy reason.

 

[Jason1377]

Damn hopefully mine will roll over when it gets that high it's still a baby at 168.900 miles, it's a "93 n my goal is 500k before she retires for a lil while

 

[Shadetreemechanic]

My understanding is that it was a cost saving thing with ford early in the digital odometers. They all do that. Ford apparently saved some coin by having it go back to 300 at 399. I think that glitch went away in the latter obs trucks.