Pre-Purchase Inspection (PPI): What It Covers and When to Get One
Also called: PPI, Used car inspection
A pre-purchase inspection is an independent mechanic’s evaluation of a used car before you buy it — typically a road test, an under-car and engine-bay inspection, a diagnostic scan, and a check for prior accident repairs. It finds mechanical and repair problems that no VIN record can show.
By the CarWhere Research team · Updated November 2026
How it affects a buyer
VIN records tell you what was reported about a car; an inspection tells you what condition it’s actually in. A PPI can catch worn brakes and tires, leaks, a slipping transmission, stored diagnostic codes, rust, and signs of accident repair — paint-thickness differences, panel gaps, non-factory welds. The cost is small next to a single major repair, and the findings are leverage: documented problems justify a lower price, a repair before sale, or walking away. The FTC recommends having a used car inspected by an independent mechanic before you buy.
How to check it
Choose a mechanic who works for you, not the seller — ideally one familiar with the brand. Ask for a written report with photos. Combine it with the paperwork side: run the VIN for salvage-auction and stolen-vehicle records and open recalls, and read the title. A seller who refuses an independent inspection is giving you information too.
What a good PPI covers
A road test at city and highway speeds; brakes, tires, suspension, and steering; fluid condition and leaks; an OBD-II scan for current and stored codes; the cooling and charging systems; signs of flood exposure; and a body check for repaint, filler, and structural repairs. Performance and luxury models benefit from brand-specific checks.
Check it on a specific car
Frequently asked questions
Is a pre-purchase inspection worth it?
For almost any used car worth more than a few thousand dollars, yes. It costs far less than the repairs it can uncover, and its findings give you negotiating leverage.
Will a dealer let me get a pre-purchase inspection?
Most reputable dealers allow one, either at a nearby shop or by a mobile inspector. Treat a refusal as a red flag.
Does a certified pre-owned car need an inspection?
A manufacturer CPO car has already passed the brand’s checklist, but an independent inspection is still a useful second opinion, especially on higher-priced vehicles.