This SAE Recommended Practice applies to speedometers, odometers, and speedometer drivestypical of passenger vehicles, buses, and trucks used for personal or commercial purposes. The method ofdetermining wheel revolutions per unit distance (3.1) and overall system design variation (3.3.3) are applicableto passenger cars only. Comparable recommendations for trucks and buses are under development. Thedata of tachometers is applicable to vehicular use, as previously described, and also to stationary and marineengines and special vehicles.
SAE J678-1988 history
2011SAE J678-2011 Speedometers and Tachometers Automotive
1988SAE J678-1988 Speedometers and Tachometers - Automotive, Recommended Practice
1984SAE J678-1984 Speedometers and Tachometers - Automotive@ Recommended Practice