Speedometer - Calibration Specifications
86VW1Applies To
ALL
1984 ON
Group
90
Subject
Speedometer
Part Identifier 90 06
Key Points
Speedometer Calibration
C
Number
86-03
August 29, 1986
Speedometer head
As of May 1983 the existing regulations (FMVSS 127) concerning vehicle speed indication were cancelled by the Department of Transportation (DOT).. Starting May 1983, the only requirement is that the vehicles' speedometer indicate a higher speed than is actually being driven.
Speedometers having European calibration specifications were installed in vehicles for model years 1984 through 1985 (until December 1984 production). These speedometer heads have a basic tolerance of (+) 6.2 miles per hour with an additional (+) 5% of the actual speed driven. For example:
Actual Speed 50 Miles Per Hour
+ Basic Tolerance 6.2
+ 5% of Actual 2.5
Maximum indicated speed: 58.7 miles per hour*
Speedometers with the former FMVSS 127 calibration are installed starting with December 1984 production. These speedometer heads have a tolerance of (+) 3 miles per hour. For example:
Actual Speed 50 Miles Per Hour
+ Basic Tolerance 3 Miles Per Hour
Maximum indicated speed: 53 miles per hour*
*Note
It is required that vehicles be equipped with OEM tires and wheels showing only normal tire wear.
Odometer
The odometer reading is independent of the speed indication and is regulated by the Federal Trade Commission (FTC). The tolerance of the odometer indication is (-) 1% to (+) 3.75% of the actual number of miles driven.
Note
The number printed on the speedometer face plate beneath the word MPH shows the number of revolutions required by the speedometer cable multiplied by 100 to travel a distance of 1/100th of a mile (52 feet, 9.5 inches).