What the Wheel Fitment API returns

Vehicle description and attributes

Make, model, year, body type, doors, and platform metadata — the structured identity of each modification returned by the API.

Vehicle generation & production years

Generation code and production start / end years — distinguishes facelifts and chassis changes that affect fitment within the same nameplate.

Vehicle region

Market the vehicle was officially sold in — one of our 14 regions (USDM, EUDM, JDM, and more). The same model may carry different factory fitments by region. See the full region list →

Trim levels & options

Trim name and option packages that influence factory wheel / tire choices — sport, offroad, and performance variants typically ship different fitments.

Vehicle images

Reference photography for each generation — useful for visual confirmation when a user is picking a vehicle in your UI. Returned as hosted image URLs.

Headline power

Output in kW, PS and hp. The source depends on how the vehicle is electrified: the combustion engine for combustion-only cars and mild hybrids, the manufacturer-declared system output for full and plug-in hybrids and EVs, the motors for range-extenders. The horsepower filters match this same figure — useful for load-index and speed-rating checks on high-performance variants.

Engine power vs. system power

engine_power is the combustion engine alone — the figure most other vehicle-data sources publish, so use it to reconcile hybrids against another dataset. system_power is the manufacturer-declared total of the whole powertrain, never the sum of its parts. engine_power_secondary holds the rating of the same engine on its second fuel for LPG, CNG and flex-fuel cars.

Electrification level

Mild hybrid, full hybrid, plug-in hybrid, range-extender, battery electric or fuel cell — an axis independent of fuel, so a 48V mild hybrid keeps its real base fuel and is classified here instead. Lets you label or group EV and hybrid fitments without parsing fuel strings.

Primary & secondary fuel

Stable fuel codes with translated titles (petrol, diesel, electric, cng, lpg, ethanol_blend …). A second fuel makes bi-fuel and flex-fuel vehicles explicit — petrol + LPG, petrol + CNG, petrol + ethanol blend. The same codes drive the fuel filter, which matches primary, secondary and legacy fuel in one parameter.

Electric motors

Peak output in kW, PS and hp plus the manufacturer motor code, one entry per driven axle — front, rear, or both for dual-motor EVs and AWD hybrids. Combined with engine power this shows how the headline figure is composed.

Engine type, displacement, engine code

Cylinder layout, displacement in litres, the legacy fuel label and the manufacturer engine code — lets you disambiguate fitments across engine options within a single trim. The engine object keeps its historical shape for existing integrations.

Absence is explicit rather than silent: not_applicable means the attribute cannot apply (a BEV has no engine), not_reported means it applies but has not been recorded yet, unknown means no claim is made. Motor and second-fuel ratings are being recorded gradually across electrified and bi-fuel vehicles.

Original Equipment (OE) tire & wheel fitment

Factory-fitted tire and rim sizes for passenger cars and light commercial vehicles (LCVs) — the spec as delivered by the manufacturer.

Aftermarket & manufacturer-optional sizes

All additional tire and wheel sizes approved by the manufacturer or commonly fitted in the aftermarket — typically multiple alternatives per modification.

Load index & speed rating

Maximum load capacity and speed rating codes (e.g., 94V, 102H) per tire size — required for safe replacement matching.

Offset (ET)

Distance in millimetres from the hub mounting face to the wheel centerline. Critical for clearance and stance calculations — available on every wheel record.

Fitment markers — run-flat, commercial, steel, winter, extra load, high load

Per-size boolean flags: run-flat tires, commercial tires (LT), steel rims, the recommended-for-winter flag, plus two independent load-class markers — extra load (XL) and high load (HL). Lets you filter or label catalog rows without extra joins.

Center bore

Hub bore diameter in millimetres — determines whether a wheel sits hub-centric or needs a centering ring.

Thread size

Lug / bolt thread spec (e.g., M14x1.5, M12x1.25) — required to source correct fasteners.

Wheel fasteners (lock type)

Fastener type per vehicle — lug nuts, bolts, or center lock (a single central nut used on motorsport and select high-performance models). Some premium aftermarket wheels require a specific type.

Wheel torque tightening

Manufacturer-recommended torque (Nm and lb-ft) for tightening lug nuts / bolts. Surface this in service UIs and installer-facing tooling.

Tire pressure

OEM front / rear cold-tire pressures in bar and PSI — often varies by load condition and tire size.

Aftermarket upsteps (wheel + tire)

Recommended plus-size progressions (+1, +2, +3) pairing wheel diameter increases with matching tire sizes that preserve overall rolling diameter.

Winter-wheel downsizing

Suggested smaller diameter / narrower tire combinations for winter use — preserves speedometer accuracy while improving snow traction and reducing cost.