Why a Clean CARFAX Isn't Proof of Honest Mileage

We include a full CARFAX report with every inspection, because it's one of the best tools available. But too many buyers treat a clean report as a clean car. When it comes to mileage, that's a dangerous assumption.

How history reports catch rollbacks

Reports work by collecting odometer readings from service shops, inspections, auctions, title transfers and registrations. If a car is recorded at 90,000 miles one year and 40,000 the next, the database can flag a potential rollback. That's powerful — and it's why CARFAX can estimate that around 2.45 million vehicles on the road are suspected of a rollback.

Where they can't see

• Blocked from early on. If a mileage blocker has been fitted for most of a car's life, every recorded reading is already false. The history is consistent — consistently wrong.
• Rolled back before the first recorded reading. No earlier true reading means nothing to compare against.
• Thin records. Cars serviced at independent shops that don't report data, or owned privately with few inspections, may have long gaps.
• Out-of-country history. Imports may have histories that US databases simply don't hold.

Why we use more than one source of truth

A history report tells you what was recorded. A diagnostic cross-check tells you what the car's own modules stored. A forensic inspection tells you whether anyone has been behind the dash. And a wear assessment tells you how the car has actually been used. Agreement between all four is reassuring. Disagreement is where the truth tends to be.

CARFAX or carVertical?

For a car that's lived its life in the US, CARFAX generally has the deeper record. carVertical's strength is international data, so it's useful for imported vehicles. We use CARFAX as standard and add carVertical when a car's history crosses borders.

Statistics cited: CARFAX odometer rollback data (December 2025); National Highway Traffic Safety Administration. General information only — not legal or financial advice.