Understanding the Japanese Auction Grading System

Every JDM import comes with an auction sheet that grades its condition on a scale most buyers never learn to read properly. Here's exactly what every grade, sub-grade, and symbol actually means.

The Most Important Document You'll Ever Read Before Buying

Every car sold through a Japanese auction house comes with an inspection sheet that grades the vehicle's condition using a standardised system understood across the industry. Learning to read it properly — rather than relying solely on a translated summary — is one of the most valuable skills any prospective JDM buyer can develop.

The Overall Condition Grade

Japanese auction houses use a numerical scale, typically 1 to 6, with half-point increments commonly used:

Grade 6: Effectively new or unregistered. Extremely rare on older cars.

Grade 5: Excellent condition, minimal wear, often very low mileage.

Grade 4.5 and 4: Very good condition — the range most buyers of 1990s and 2000s performance cars should target.

Grade 3.5 and 3: Average condition with more noticeable wear.

Grade 2: Below average, often with more significant issues.

Grade 1: Poor condition.

Grade R: Repaired accident history. Always ask exactly what was repaired and how.

Grade RA: Similar to R but the repair was assessed as closer to original condition.

Interior and Exterior Sub-Grades

Beyond the overall grade, most sheets include separate letter grades for interior and exterior condition, typically A to E, where A is excellent. A car might carry an overall grade of 4 but an interior graded B and exterior graded C. Always check both rather than relying on the headline number alone.

Reading the Damage Diagram

Auction sheets include a line diagram of the car marked with standardised symbols indicating damage or repair location and type. Each auction house uses slightly different conventions, but every mark corresponds to a specific, identifiable issue on the actual car.

A responsible importer will translate this diagram in detail before you commit. Always ask for a full translation of every symbol, not just a general summary.

Mileage Verification

Auction sheets record the odometer reading along with a note on whether the inspector believes it's genuine, suspect, or unverifiable. Japan's meticulous maintenance culture makes fraud rarer than in many markets, but it isn't impossible. Cross-reference this note against shaken history wherever possible.

What the Grade Doesn't Tell You

The grading system is a snapshot of cosmetic and basic mechanical condition at inspection. It doesn't guarantee engine internals are healthy, doesn't fully reflect modification history, and doesn't account for how the car was actually driven. Treat the grade as a strong starting filter, not a substitute for detailed questions and, where budget allows, an independent pre-purchase inspection.