Speedometer error between sizes

Extraits de code

curl "https://api.oanor.com/tiresize-api/v1/compare" \
  -H "x-oanor-key: oanor_test_..."

await fetch("https://api.oanor.com/tiresize-api/v1/compare", {
  headers: { "x-oanor-key": "oanor_test_..." }
});

$ch = curl_init("https://api.oanor.com/tiresize-api/v1/compare");
curl_setopt($ch, CURLOPT_HTTPHEADER, ["x-oanor-key: oanor_test_..."]);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
$out = curl_exec($ch);

import requests
requests.get(
    "https://api.oanor.com/tiresize-api/v1/compare",
    headers={"x-oanor-key": "oanor_test_..."}
)

Exemple de réponse

Une réponse réelle de ce endpoint, capturée lors du dernier contrôle de santé.

{
    "data": {
        "note": "Speedometer is calibrated to the original rolling diameter. A larger new tyre makes the speedo read low: true speed = indicated · OD_new/OD_old. Stay within ±3 % to keep the error small.",
        "inputs": {
            "original": "205/55R16",
            "replacement": "225/45R17"
        },
        "speedometer": {
            "reads": "slow (you are going faster than shown)",
            "true_speed_at_indicated_100": 100.3798
        },
        "new_diameter_mm": 634.3,
        "original_diameter_mm": 631.9,
        "diameter_difference_mm": 2.4,
        "ground_clearance_change_mm": 1.2,
        "diameter_difference_percent": 0.3798
    },
    "meta": {
        "timestamp": "2026-06-05T19:50:20.881Z",
        "request_id": "5222a9cb-e8cd-496b-9295-74268ea4de78"
    },
    "status": "ok",
    "message": "Tyre comparison / speedo error",
    "success": true
}