The rear wheels push the car forward — acting like a dolly or a shopping cart. In this case, the front wheels do only the steering. Read More »
Rich Mixture
The condition that exists when the ratio of fuel to air is very high. A rich mixture can contribute to inefficient burning of fuel, resulting in poor mileage, higher emissions and black smoke from the exhaust pipe. Read More »
Red Flag
A solid red flag is used to stop the race immediately. Generally races are stopped for bad accidents or weather. Occasionally, a multiple car pileup will halt a race. Wreckers and fire marshals clear the track of cars, debris and fluids. Alternatively, rain makes the surface of the race track dangerous. Once NASCAR officials authorize the race to start again, ... Read More »
RPM
Revolutions Per Minute — a unit of measure used to express the rotational speed of an engine. Read More »
Remote Keyless Entry
A small hand-held device used to lock and unlock a vehicle from up to 30 feet away. Many times the device contains not only a lock/unlock for doors and trunk, but also a panic button that causes the lights to flash and the horn to honk if an intruder is seen near the vehicle. Most remote keyless entry devices turn ... Read More »
Residual
A conservative projection of the market value of a vehicle at the end of a lease. Residual values are provided by major auto manufacturers or independent companies that specialize in auto valuation. A higher residual value will lower the monthly payment. However, the vehicle must be resalable at the residual amount or the lessor will lose money. Conversely, adjusting the ... Read More »
Restrictor Plate
A plate attached to the carburetor that limits the amount of airflow entering the combustion chamber. It decreases horsepower. Read More »
Rev Range
Automotive jargon for the range of speeds (expressed as revolutions per minute) in which an engine is designed to operate. The lowest point in the rev range is the idle speed; the highest point is the redline. Read More »
Rolling Start
A form of race start that begins with the cars already in formation, while also in motion. Read More »
Road Course
A closed course with turns to both the right and the left mimicking a normal road. Read More »
