I had a dealer tell me that if you divide the mileage by the operating hours you get the average mph and can tell what type of usage the car has had. For instance my car had 12800 miles and the dome report showed 379 hours meaning it has an average speed of 33mph. they then gave me the chart below to show usage.

0 - 30 Cars and Coffee usage
30 - 50 Highway miles/usage
50> Track usage.

Is this true or is this a rough guide to figure out how the car was treated? My car comes in low on the highway miles . Considering it had a rollbar in it when I bought it I suspect one of the previous 2 owners probably tracked the car at least a little bit. That said I am sure there are people/posers that installed the rollbar just for aesthetics. I am not worried about it at all since I have heard stories about cars with twice the mileage as mine that are ALL track miles with no issues.

Thoughts?

 

What's important about a DME scan is what zone the overrevs occurred. If you have a lot of time in Zone 1 it means the person drove it and hit red line a bunch, probably track miles or spirited driving but all in all nothing to be concerned with. Zone 2 = woops missed a shift so hopefully little to no time here, Zone 3+ danger Will Robinson danger!

If you do have a car with higher ranges the next question was when did the last overrev occur and how much time has been put on the car since. For example if you have a range 5 overrev at hour 100 and the car has 500 hours, the engine is most likely fine since it has had 400 hours since the horrible miss shift.

 

Car has a clean DME and was CPO'd. I am not worried at all. I was just curious about if what the dealer was trying to tell me had any truth to it.

 

Generally speaking there is some truth to what the dealer said. It is a rough guide though.

~30mph average speed is where most cars fall. Less than that speed are probably garage queens.

Higher than that and with relatively low miles is generally where tracked cars fall.

Often (in fact I dare say always) the DME overrev counters will show the engine spent some time in the upper RPM ranges and even if there were no overrevs of the serious sort there'll be plenty of the benign ones.

A real low average speed can be a sign the car's odometer was rolled back, so to speak.

 

DME doesn't show upper RPM range. It shows overrevs only from what I understand. Range 1 = hitting the rev limiter, Range 2 = over the rev limiter which is most likely a bad shift. Range 3+ = VERY bad miss shifts like 5th to 2nd when you meant 4th. If you google it there is a chart for what each RPM is in the respective range.