Front wheel angles / Toyota Rav4
Wheel angles significantly affect vehicle stability, tyre wear and fuel consumption. The following differentiates between the various wheel angles:
Camber is the angle between the plane of rotation and the vertical of the wheel. It can be positive if the wheels are angled outwards, or negative if the wheels are angled inwards. The camber angle mainly affects the evenness of wear of the front tyres. If one wheel's camber is positive and the other is negative, the car may drift sideways in a straight line.
Toe-in is the difference in distance between the rim flanges measured at the front and rear of the wheels at the level of the wheel centres. Positive convergence means that the wheels are closer together at the front than at the rear, at the level of their centres. Negative toe-in means that the wheels are further apart at the front than at the rear.
Transverse wheel alignment is the angle between the axis of inclination of the steering knuckle and a vertical line drawn through the wheel mounting point in the longitudinal plane of the vehicle.
The camber and pivot axis tilt angles bring the wheel contact points closer to the axle of the steering knuckle. This supports the so-called "running-in leverage". The lower the running-in leverage, the easier it is to steer the vehicle. In addition, shocks from surface irregularities are less likely to be transmitted to the steering.
Pitching angle is the angle between the steering knuckle's pivot point and a vertical line drawn through the wheel mounting point in a plane perpendicular to the car's longitudinal axle. The axle, in relation to which the wheel is pivoted, is positioned in space so that its lower part is inclined forwards. This inclination angle is called positive inclination. A positive angle ensures better stability and stabilisation of the steered wheels when driving straight ahead.
Wheel alignment checks and adjustments must be carried out by a workshop due to the complexity of the equipment used.
Front tyre angles
Only radial tyres are fitted to the car.
Radial tyres have the cords arranged along the shortest path between the tyre beads. The bracing belt surrounds the thin and resilient tyre carcass and gives the tyre stability.
With tubeless tyres, the inner-tube has been replaced by a vulcanised inner-liner with a high air-tightness. The bead of such a tyre must be mounted securely and airtight onto the rim. The absence of a tube in the tyre reduces the weight of the wheel and facilitates mounting on the rim.
The tyre marking is on the tyre sidewall. The tyre width, tyre construction and rim diameter are the minimum information you need for the tyre marking.
The grooves in the tyre tread pattern contain "tyre wear indicators", 1.6 mm high, at right angles to the direction of travel. These six to eight (depending on the tyre manufacturer) wear indicators are located at regular intervals around the circumference of the tyre. Markings on the tyre sidewall (such as the letters "TWI" or the triangle symbol) indicate the location of the tyre wear indicators.
Tyres should be run with a minimum profile depth of 1.6 mm, i.e. the profile grooves should be at least 1.6 mm deep across the tyre surface.
Optimum performance is only achieved when tyres of the same design are mounted on all wheels.
Do not mount tyres on damaged, warped or corroded rims.
When mounting directional tyres (identified by the arrow on the tyre sidewall), ensure correct direction of rotation. This will ensure optimum tyre behaviour in terms of grip and wear.
It is particularly important to maintain the recommended tyre pressure when driving at high speeds. For this reason, always check the tyre pressure at least once a month and before every long journey.
Always check the air pressure when the tyres are cold.
WARNING
Never deflate tyres when the tyre pressure is too high.
If the load changes significantly, adjust the tyre pressure accordingly.
A decreased or increased tyre pressure shortens tyre life and impairs the car's roadholding.
Regular checks check your tyres in good time to detect excessive wear and correct the cause, helping to avoid more serious consequences.
On all-wheel-drive vehicles, all tyres must also be from the same make and model. Otherwise the inter-axle differential will not correctly distribute the engine torque to the rear axle due to the resulting difference in rotation speed between the two axles, which can have a negative impact on the vehicle's handling.
Wheel imbalance can occur when the vehicle is operated for various reasons, and this can cause the wheel to vibrate in the steering wheel.
Wheel imbalance will cause increased wear on the steering, tyre and suspension components, so if you notice any imbalance, have the wheels rebalanced.
