Four Wheel Drive Concepts
Offroad Driving Techniques
Vehicle Recovery Techniques
   Gear Ratios
   Metric Tyre Height

Gear Ratios. A change in tyre size changes your overall gear ratio. This section contains calulators to calulate Effective Gear Ratio, Engine RPM at a Given Speed, Equivalent Ratios for New Tyres, Speedometer Correction (Tyre Swap Only) and Speedometer Correction (Tyre and Gear Swap) with your new tyres.
Metric Tyre Height . Knowing the mounted height of a tyre is important to working out overall gear ratios and engine rpms. This calculator presents a formula for calculating the height of a metric tyre.