1CARS Race

Each car is a specific version from our catalog. The race uses its power (kW), kerb weight plus a 75 kg driver, official 0–100 km/h, top speed, drive type, gearbox and size. If a figure a track needs is missing, the car is marked “not race-ready” for that track and the page says which figure is missing. Where we have to fill a gap with a standard approximation - air drag from body type, top speed from power and drag, a typical gear-shift time - the car’s notes say “estimated” or “assumed”.

Randomness is small and bounded: dry or wet (one race in four is wet), a 0–15 km/h headwind on the Autobahn, a reaction time of 0.15–0.40 s at the lights and ±1.5 % driver form. The seed in the link fixes all of them, so a shared link always replays the same race; “Rematch” uses a new seed.

Each car gets five scores from 0 to 100: Power (kW per tonne), Grip (drive type, weight and a tyre class assumed from power per tonne - tyre sizes are not in our catalog), Handling (weight, height, body type and wheelbase), Top speed and Launch (official 0–100 km/h, or the race physics when the catalog has no time). Classic cars (25+ years) also show Reliability: a 2–12 % chance per race of a breakdown that sends the car into limp mode. The performance index (PI, 100–999) weighs Power 32 %, Launch 18 %, Grip 18 %, Handling 18 % and Top speed 14 %; classes are D below 400, C 400–499, B 500–599, A 600–749 and S from 750. Every card links to the source figures under “Where these numbers come from”.

Drag Duel: the run starts when you tap after the green light (reaction time counts; a jump start costs 1.0 s). In every gear the rev needle climbs from the moment you engage it to the limiter. Shifting in the green zone (top 14 % of the band) is perfect; earlier shifts leave the engine below its power band (−6 % for 0.5 s or −18 % for 0.9 s), and waiting on the limiter adds no speed at all. Mountain Pass: 5–7 corners from the seed, each with a safe speed √(grip × g × radius) from your car’s Handling, the tyres and the surface. Tap brake at the yellow marker: brake too early and you crawl into the corner, too late and you run wide (to 72 % of the corner speed) or, on wet, snowy or gravel roads, spin (2 s). The rival is a bot with a cautious, average or aggressive personality that sets its reaction, shifting and braking. The live picture uses the same 0.01 s physics as the server; the official result is always calculated on the server from the moments you tapped.

Up to three parts: sport, rain or off-road tyres (one set), ECU tune (+8 % power, +2 % breakdown chance), weight reduction (−5 %), sport suspension (+0.05 g in corners) and nitro (+15 % power for 3 s, once). Each part raises the PI, and a race is capped at the higher stock class of the two cars, so tuning can close a gap but cannot turn a hatchback into a hypercar. Weather (dry 62 %, wet 26 %, snow 12 %), surface (gravel on a third of mountain passes), wind of up to 15 km/h, the rival’s personality, breakdowns and rare punctures (1.5 %) all come from the seed in the link and are shown before the start. Coins, unlocked parts and records are stored only in your browser.

Time-step physics every 0.01 s: thrust = power ÷ speed, limited by tyre grip on the driven wheels (FWD 56 %, RWD 64 %, AWD 95 % of the weight); minus air drag (∝ speed²) and rolling resistance; no thrust during gear shifts. When the catalog has an official 0–100 km/h time, the model is calibrated to match it exactly. Each driver gets a reaction time of 0.15–0.40 s at the lights.

Same physics as the drag strip, from 100 km/h, over 5 km. The catalog top speed is a hard ceiling (gearing or limiter); without it, top speed is estimated where power equals air drag plus rolling resistance and labelled "estimated". A random headwind of 0–15 km/h applies to everyone.

Ten 420 m straights at 6 % uphill (physics as on the drag strip, gravity included) and ten 40 m hairpins with a 22 m radius. Hairpin speed = √(grip × g × radius); grip starts at 0.95 and drops for heavier cars (−0.06 per 500 kg over 1,300 kg), taller cars (−0.2 per metre over 1.35 m) and SUV/van/truck bodies, rises slightly for coupés and roadsters. Braking into each hairpin uses the same grip. Wet roads: grip × 0.72, AWD +0.04.

Eight 150 m sections, each with a random difficulty (0.7–1.45, the same for every car). Section speed = 38 km/h × capability ÷ difficulty. Capability = drive (4x4 1.0, AWD 0.92, RWD 0.55, FWD 0.6) × body (off-roader 1.0, pick-up 0.97, SUV 0.93 … sedan 0.5, coupé 0.4) × weight (−7 % per 1,000 kg over 2,300 kg) × a small power-per-tonne factor. Ground clearance is not in our catalog yet, so body type stands in for it. Mud: two-wheel drive × 0.72, AWD/4x4 × 0.93.

The 50 km/h limit is respected. Blocks of 160–250 m: accelerate (same physics as the drag strip), brake at 3.5 m/s², wait 1 s at each stop. In the two tight turns the speed is 18 km/h for a 4.0 m car, 12 % slower per extra metre of length (a proxy for turning circle, which our catalog does not hold), up to 10 % quicker for shorter cars.

Out of 4,963 versions in the catalog, 4,159 can race on at least one track: drag strip 1,463, Autobahn 1,463, mountain pass 1,099, off-road trail 3,788, city sprint 1,203. The numbers grow as we add kerb weights, 0–100 times and dimensions to the catalog.