Piston Slap: Hacking the Unrollable Odometer?

Sajeev Mehta
by Sajeev Mehta
piston slap hacking the unrollable odometer

Brian writes:

I had a conversation with someone the other day who claimed his mechanic rolled back the odometer on his car. This is a late-model car with a digital odometer. I always thought digital odometers were protected from this, but a quick Google search reveals that it’s actually quite common and easy to roll back a digital odometer. I guess this is now something a buyer has to worry about on top of everything else when buying a used car.

For example, how could you ever tell a car was rolled back — say, 10,000 miles — when the car is legitimately in good condition?

What are your thoughts on this? And how can a buyer protect themselves?

Sajeev answers:

My thoughts are simple: as mentioned in previous Piston Slaps, get a PPI if you’re worried about buying a misleading motor. Carfax might catch an odometer discrepancy — paste the VIN here to check. You really need a PPI for peace of mind, and if a truck, van, etc. isn’t necessary (and you have [s]good[/s] some credit and five figures to drop) buy a new, entry-level sedan that’s being disposed of at loss leader prices.

You can indeed put a price on your peace of mind, even if it means owning a vehicle you’d rather not be seen in. The threat is real — older digital units are re-programmable with a chip swap, as this video shows. There’s also an OBD-II tool you can plug in for “mileage correction.” Or, in the case of this VW Bora (Jetta), there’s an app for that.

Buyer beware, it’s a brave new world. Get a PPI, learn the basics of used car inspection, and do a VIN check on Carfax.

[Image: Shutterstock user iQoncept]

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15 of 42 comments
  • Richard Richard on Mar 07, 2017

    Buying used is real easy; 1.One owner 2.Complete service history (CarFax) Preferably @ dealer 3 Clean CarFax It's that simple Footnote 1st. choice TOYOTA

    • See 6 previous
    • Vulpine Vulpine on Mar 08, 2017

      @gtem Please don't let it be a certain blue over tan, 2WD, 1990 F-150 XLT Lariat with the 5.0L EFI under the hood.

  • Mmreeses Mmreeses on Mar 07, 2017

    If the gain is high and the chances of being caught are low, someone/somewhere is going to cheat. Self-evident aphorism from Dilbert.

  • Dal20402 Dal20402 on Mar 07, 2017

    Buy only ridiculously high-mileage vehicles. Problem solved! - Sincerely, someone who bought a 186k mile Acura

  • Felix Hoenikker Felix Hoenikker on Mar 07, 2017

    Here in PA, mileage is recorded at registration by the owner and at annual inspection by the inspection mechanic. Both mileage readings and OBD codes are uploaded to the DOT. All of that is turned over to Carfax. The only way to get away with odometer fraud without leaving a trail is to roll back the odometer annually before each inspection.

    • Jalop1991 Jalop1991 on Mar 07, 2017

      Or launder the car through one of the more lackadaisical states.