The driver's workbench
Accurate car & tyre tools.
No sign-up, no nonsense.
Interactive calculators built by enthusiasts, for enthusiasts — the kind of working-out a one-line web answer can't do for you. Free, fast, and ad-supported.
Tools
Tyre Size & Speedo Error
Compare two tyre sizes: speedometer error, diameter change, revs/mile and ride height.
Coming soonTow-Car Matcher
Kerb weight vs caravan MTPLM, the 85% guideline, noseweight and payload.
Coming soonEV Charging Time & Cost
Battery, charger and tariff → charge time, cost and cost-per-mile vs petrol.
Coming soonJourney Fuel Cost
MPG, distance and pump price → trip cost, with multi-vehicle comparison.
Coming soonGear Ratio & Speed
Final drive, gearing and tyre size → speed at RPM for swaps and re-gearing.
Coming soonCost-to-Run Data
Maintained cost-per-mile tables across petrol, diesel and EV by model.
Why MotorBench?
Tools that actually compute, not just look up a number. Anyone can tell you a single figure. The questions that matter — "will these tyres throw my speedo out?", "can my car legally tow this caravan?", "is the EV really cheaper per mile than my petrol?" — need real, multi-input working-out. That's what we build.
Every tool shows its method, every estimate carries an honest caveat, and there's never a sign-up wall to get an answer.