Wheel Fitment API

Calculate plus/minus sizing candidates for an OE wheel/tire combo. Given the OE rim and tire, enumerates rim diameters from steps_min to steps_max around OE (e.g. steps_min=-1, steps_max=2 with an 18-inch OE covers 17-20 inches in one call; the OE diameter is always included) and returns the tire/rim combinations whose design section width and overall diameter stay within s_max / do_max of OE. Tighten do_max for "without changing the overall diameter" requests. Each option carries step = rim diameter minus OE diameter in whole inches (0 = OE diameter; 17.5 counts as 17). Exactly one option has is_oe=true (step 0) — it echoes the requested OE combo. by_diameter lists every enumerated diameter in order, including those with count 0, as {"17": {"step": -1, "count": 12}, ...} — use it to build -1 / OE / +1 tabs. by_rim counts options per rim designation. Both summarise the WHOLE candidate list; total counts tire-rim combinations. The option rows are paginated MCP-side (limit/offset, API order: by diameter, then rim width) — a wide range with loose tolerances can exceed 300 options, so page through has_more. This is a geometric calculator only: it does not check load or speed ratings, brake/arch clearance, staggered setups or high-flotation sizes. Can be called freely without user initiation.

Check whether a high-flotation (LT) tire size fits a specific vehicle. Answers "do 31x10.50R15 tires fit my 2000 Chevy Blazer?" in one call: returns the vehicle's modifications (trims) where this HF tire size appears as a documented fitment. An EMPTY result means no documented fitment for that combination. Inch-based HF sizes only — for metric sizes use ws_check_tire_fitment_for_vehicle. The API has no year parameter, so 'year' is filtered MCP-side against each modification's production range (start_year/end_year); each row echoes its range so near-misses can be explained. Each row carries engine {fuel, capacity, hp} and a powertrain summary (field vocabulary in ws_list_modifications). IMPORTANT: This is a Search method — only call when a user explicitly requests a fitment check. Do not call in autonomous loops.

Check whether specific rims fit a specific vehicle (make + model, optionally year). Answers "will 5x114.3 17x7 ET40 rims fit my 2020 Honda Civic?" in one call: returns the vehicle's modifications (trims) where this rim appears as a documented fitment. An EMPTY result means no documented fitment for that combination — the rim is likely incompatible or undocumented. The API has no year parameter, so 'year' is filtered MCP-side against each modification's production range (start_year/end_year); each row echoes its range so near-misses can be explained. Each row carries engine {fuel, capacity, hp} and a powertrain summary (field vocabulary in ws_list_modifications). Prefer this over ws_search_by_rim + ws_search_by_vehicle comparison when the user names a specific vehicle. IMPORTANT: This is a Search method — only call when a user explicitly requests a fitment check. Do not call in autonomous loops.

Check whether a specific tire size fits a specific vehicle (make + model, optionally year). Answers "do 225/45R17 tires fit my 2020 Honda Civic?" in one call: returns the vehicle's modifications (trims) where this tire size appears as a documented fitment. An EMPTY result means no documented fitment for that combination. Metric sizes only. The API has no year parameter, so 'year' is filtered MCP-side against each modification's production range (start_year/end_year); each row echoes its range so near-misses can be explained. Each row carries engine {fuel, capacity, hp} and a powertrain summary (field vocabulary in ws_list_modifications). Prefer this over ws_search_by_tire + ws_search_by_vehicle comparison when the user names a specific vehicle. IMPORTANT: This is a Search method — only call when a user explicitly requests a fitment check. Do not call in autonomous loops.

Find compatible tire sizes for a given rim specification. Returns tire sizes (e.g. '245/70R17') with the number of vehicle generations that use each tire on this rim. Set diameter_range to also include tires for ±N inch rim diameters. Useful for tire product recommendations on wheel product pages. IMPORTANT: This is a Classified method — only call when a user explicitly requests tire recommendations for a rim. Do not call in autonomous loops or for bulk generation.

Drill down into individual trims for a generation from ws_find_vehicles_for_package. PREREQUISITES — call ws_find_vehicles_for_package first to get: - make, model, generation slugs (from the results) - Use the same rim AND tire parameters and tolerances as the parent search Returns per-vehicle rows with OEM wheel specs (rim, tire) and fitment deltas vs the searched rim + tire package. Completes the e-commerce chain: package search → generations → specific trims. IMPORTANT: This is a Classified method — only call when a user explicitly requests the trims behind a package compatibility result. Do not call in autonomous loops or for bulk generation.

Drill down into individual trims for a generation from ws_find_vehicles_for_rim. PREREQUISITES — call ws_find_vehicles_for_rim first to get: - make, model, generation slugs (from the results) - Use the same rim parameters and tolerances as the parent search Returns per-vehicle rows with OEM wheel specs (rim, tire, frontspace, backspace) and fitment deltas vs the searched rim. IMPORTANT: This is a Classified method — only call when a user explicitly requests the trims behind a rim compatibility result. Do not call in autonomous loops or for bulk generation.

Drill down into individual trims for a generation from ws_find_vehicles_for_tire. PREREQUISITES — call ws_find_vehicles_for_tire first to get: - make, model, generation slugs (from the results; the catalog slugs from ws_list_generations are the same and work here too) - Use the same tire parameters (section_width, aspect_ratio, rim_diameter) as the parent search. There are no tolerance or sort parameters: matching is the same as the parent — exact rim diameter, tire width and overall diameter within a fixed ±2 mm. Returns per-trim rows: production years, regions, the closest OEM rim/tire pair (oem_rim, oem_tire, oem_rim_diameter/width/offset, oem_tire_width_mm/diameter_mm/aspect_ratio), the match deltas against that pair (ow_delta_mm, od_delta_mm, od_delta_percent, ar_delta) and load data (load_kg, load_index). The mm deltas are the match precision against the nearest OEM pair (always within ±2 mm) — NOT how far the tire departs from stock. For upsize/downsize (plus/minus sizing) use ws_calculate_upsteps. oem_tire_aspect_ratio and ar_delta are null for high-flotation and alpha-numeric OEM tires (e.g. 37x12.50R17LT, G78-14). The result can be empty with HTTP 200 for a wrong slug or tire params that differ from the parent search — re-check those first. A genuinely empty drill-down also happens briefly after a catalog update (parent and drill-down are cached independently); that is not an error. IMPORTANT: This is a Classified method — only call when a user explicitly requests the trims behind a tire compatibility result. Do not call in autonomous loops or for bulk generation.

Find vehicles compatible with a rim + tire package. Most precise classified search — considers both physical wheel fitment (backspace) and tire size compatibility simultaneously. Use sort='fitment' to put the closest matches first. For e-commerce combo/bundle product pages. To drill into a specific generation, use ws_find_vehicle_modifications_for_package. IMPORTANT: This is a Classified method — only call when a user explicitly requests a compatibility list or product card for a rim + tire package. Do not call in autonomous loops or for bulk generation.

Find vehicle generations compatible with a given rim via geometric backspace calculations. Unlike ws_search_by_rim (which does direct 1:1 wheel pair matching), this endpoint uses advanced 2D geometric filtering based on frontspace/backspace calculations to determine physical fitment. This yields broader results — any vehicle where the rim physically fits the wheel housing, even if this exact spec isn't in the OEM database. Returns make/model/generation with fitment deltas (frontspace/backspace), load capacity, and OEM ratio ranges. Use sort='fitment' to put the closest matches first on product pages. Note: in some cases spacers or special bolts/nuts may be required. Always verify rims don't interfere with brake calipers or extend beyond the wheel arch. For e-commerce product pages: "This wheel fits: BMW X5, Audi Q7..." To drill into a specific generation, use ws_find_vehicle_modifications_for_rim. IMPORTANT: This is a Classified method — only call when a user explicitly requests a compatibility list or product card for a rim. Do not call in autonomous loops or for bulk generation.

Find vehicle generations that use a specific tire size. Simplest classified search — matches tire dimensions only, no bolt pattern or backspace filtering. For e-commerce: "This tire fits: Honda Civic, Toyota Camry..." To drill into a specific generation, use ws_find_vehicle_modifications_for_tire. IMPORTANT: This is a Classified method — only call when a user explicitly requests a compatibility list or product card for a tire. Do not call in autonomous loops or for bulk generation.

Get computed geometry, population stats, and hints for a wheel/tire spec. Auto-detects mode from parameters: - rim: rim_diameter + rim_width (optionally rim_offset) - tire: section_width [mm] + aspect_ratio + rim_diameter - hf_tire: overall_diameter + section_width [inches] + rim_diameter - package: rim + tire params combined Use before search or classified calls to understand whether a spec is common or unusual, what tolerances to use, and what to expect. This is a utility tool — can be called freely without user initiation.

List generations for a make/model. Returns generation slugs, names, platform codes, and production spans. Alternative to ws_list_years for models with many generations (e.g. BMW 3 Series). After getting a generation, use ws_list_modifications with the generation slug.

List all vehicle manufacturers (makes). Returns slugs and names for all car brands in the database. Common starting point for vehicle fitment lookups, but not the only one — ws_list_years can also be called first (without params) to start from year. After getting a make slug, use ws_list_models to find models.

List models for a given make. Returns model slugs, names, and production year ranges. Can be filtered by year to narrow results (e.g. "which Toyota models existed in 2020?"). After getting a model slug, use ws_list_years or ws_list_generations next.

List modifications (trims) for a specific vehicle. Returns trim names, engine and powertrain specs, and production years. One of year or generation is required. Filter by power via horsepower (exact ±2.7 hp) or horsepower_min/max (e.g. "trims over 300 hp" → horsepower_min=300). After getting a modification slug, use ws_search_by_vehicle for fitment data. Each row carries two sibling blocks: - engine: legacy {fuel, capacity, type, power, code}. engine.power is the headline figure whose source depends on the electrification level: the combustion engine for combustion-only cars and mild hybrids; system power (else sum of motors, else engine) for full and plug-in hybrids; sum of motors (else engine) for range-extenders; system power (else sum of motors) for BEV/FCEV. engine.fuel is a display string (renamed without notice, e.g. 'Natural gas' → 'CNG'); group on powertrain fuel codes instead. - powertrain: combustion_engine, electrification_level, primary_fuel and secondary_fuel (fuel codes — a real code can be passed back as the fuel filter; the absence words cannot), engine_power_hp, system_power_hp, engine_power_secondary_hp, and motors [{axle, hp, code}]. The full block with kW/PS/hp and fuel titles is returned by ws_search_by_vehicle. Powertrain semantics: - engine_power_hp = the combustion engine alone on its primary fuel, excluding any electric motor. This is what most other vehicle-data providers publish as "power"; use it to reconcile hybrids against other datasets. On bi-fuel vehicles it may still be the higher of the engine's two ratings rather than the primary-fuel one (splitting them into engine_power_secondary is editorial work in progress). - system_power_hp = manufacturer-declared total of the whole powertrain. A distinct quantity only on full hybrids, plug-in hybrids and EVs with a motor on each axle; normally null on a single-motor EV, a mild hybrid, a range-extender and a pure combustion vehicle. NEVER recon…

List all market regions where vehicles are sold. Returns region slugs and display names (e.g. usdm=USA, eudm=Europe, jdm=Japan). Use region slugs to filter results in other tools.

List available years, optionally filtered by make and model. Can be called without params to get all years globally — this makes it an alternative starting point for navigation (Scenario 3: years first). Can also be called with make only to get years for that brand (Scenario 2). After getting a year, use ws_list_modifications to get trims.

Find vehicles compatible with a high-flotation (LT) tire size. HF tires use inch-based sizing like 31x10.50R15: overall diameter x section width R rim diameter, all in inches. Common on trucks, SUVs, and offroad vehicles. For metric sizes (e.g. 225/45R17) use ws_search_by_tire instead. IMPORTANT: This is a Search method — only call when a user explicitly requests a tire compatibility search. Do not call in autonomous loops.

Find vehicles compatible with given rim specs via direct 1:1 wheel pair matching. Uses a direct mapping of existing wheel pair data to vehicle specs — returns only vehicles where this exact rim (or close offset) appears in the database as an OEM or documented fitment. Does NOT calculate whether the rim would physically fit based on wheel housing geometry. Diameter and width accept either an exact value (rim_diameter, rim_width) or a min/max range pair — e.g. "18-19 inch, ET30-45" → rim_diameter_min=18, rim_diameter_max=19, rim_offset_min=30, rim_offset_max=45. One of exact or range is required per dimension. IMPORTANT: This is a Search method — only call when a user explicitly requests a rim compatibility search. Do not call in autonomous loops. For e-commerce product cards, use ws_find_vehicles_for_rim instead — it uses geometric backspace calculations for broader, physics-based matching.

Find vehicles compatible with a given tire size (metric). The response includes 'facets' (per-value car counts for speed_symbol, load_index, region, fitment — use them to offer refinements) and 'summary' (feature counts like runflat/winter + physical tire data). Echo a facet value back as a filter to drill down. IMPORTANT: This is a Search method — only call when a user explicitly requests a tire compatibility search. Do not call in autonomous loops. This tool accepts metric sizes only. For high-flotation (LT) tires with inch-based sizing (e.g. 31x10.50R15), use ws_search_by_hf_tire.

Get wheel and tire fitment data for a specific vehicle. REQUIRED parameter combination: 1. Either 'modification' OR 'region' (to narrow fitment results) 2. Either 'year' OR 'generation' (to identify the vehicle) — not required when 'modification' is provided PREREQUISITES — you MUST have valid slugs before calling: - make: lowercase slug from ws_list_makes (e.g. 'toyota', 'land-rover') - model: lowercase slug from ws_list_models (e.g. 'camry', '3-series') - modification or region: from ws_list_modifications / ws_list_regions - year or generation: from ws_list_years / ws_list_generations (skip when modification is provided) - NOTE: this endpoint accepts only ONE region (unlike other tools) Do NOT guess these values. Call the prerequisite tools first. Returns OEM and optional wheel/tire specs including rim diameter, width, offset, bolt pattern, tire sizes, and tire pressure. Each wheel has setup='symmetric' (same front/rear) or 'staggered' (different). Each row also carries the legacy engine block and the full powertrain block as the API returns them: combustion_engine, electrification_level, primary_fuel / secondary_fuel as {code, title}, engine_power / system_power / engine_power_secondary as {kW, PS, hp} or null, and motors [{axle, power, code}]. The field vocabulary, the absence words (not_applicable / not_reported / unknown) and the power semantics are described in ws_list_modifications. IMPORTANT: This is a Search method — only call when a user explicitly requests fitment information. Do not call in autonomous loops.