Ideally, the scrub radius is as small as possible. Normally, the SAI angle and the centerline of the tire and the wheel intersect below the road surface, causing a positive scrub radius. With struts, the SAI angle is much larger than the long arm/short arm type of suspension. This allows the SAI angle to intersect the camber angle above the road surface, forming a negative scrub radius. The smaller the scrub radius, the better the directional stability. Installing aftermarket wheels that have additional offset will dramatically increase the scrub radius. The newly installed wheels may cause the centerline of the tires to move further away from the spindle. This will increase the scrub radius.
A large amount of scrub radius can cause severe shimmy after hitting a bump. Four-wheel drive vehicles with large tires use a steering damper to compensate for an increased scrub radius. Scrub radius is not directly measurable by the conventional methods. Scrub radius is projected geometrically by engineers during the design phase of the suspension.
Replacement Wheels Description
Spare Tire Kit InstallationTire Terminology and Definitions
Air Pressure: The amount of air inside the tire pressing outward on each square
inch of the tire. Air pressure is expressed in kPa (kilopascal) or psi (pounds per
square inch).
Accessory Weight: The combined weight of optional accessories. Some examples
of optional accessories are automatic t ...
Meters and gauges
Example
The Nissan Armada instrument cluster provides clear and precise vehicle data,
allowing drivers to monitor performance, efficiency, and safety indicators in real
time. This ensures confident driving in all conditions.
Tachometer
Drive Mode Selector indicator*
Automatic Transm ...
Electric power steering
WARNING
If the Nissan Armada engine is turned off while driving, power steering
assist will be disabled, making the steering wheel significantly harder to operate.
If the electric power steering warning light illuminates while the Nissan
Armada engine is running, the steering assist will ...