Updated Las Vegas Taxicab Field Study

This field study has been updated (G3118) to include new transmission results from another Dodge Charger taxi cab that accumulated 12,891 hours (183,705 miles) on a single transmission fluid change. The second edition of the Las Vegas taxicab field study includes the updated transmission results along with the original engine results.

Severe Service Conditions

Taxies are notoriously hard on lubricants  due to excessive idling  and constant  stopping go driving loaded with passengers  and cargo.  Las Vegas summer temperatures  added to the challenge , topping 100°F  during this field study .ASM

Given the  unusually high amount of idle time , maintenance intervals were determined in hours rather than miles.  Signature Series 0W– 20  synthetic motor oil,  changed every 900 hours ( approximately 15,000 miles), was used in the Charger’s  engine , while the transmission used Signature Series  Multi-Vehicle  Synthetic  Automatic  Transmission Fluid , which was not changed during the study.

The vehicles operated throughout Las Vegas  up to  24 consecutive hours  each day,  shutting down only for refueling  and personal  changes.  Average speed was less than 15 mph in each vehicle,  illustrating  severity  of service.


Transmission components  prone  to the effects of lubricant failure,  including the valve body and  clutch plates,  revealed virtually no sludge and little wear  after operating without fluid change  for more than three times the original equipment manufacturer ( OEM )  drain  interval.  ATFAlthough the Charger carried a recommended  transmission fluid  change of 60,000 miles  in severe service,  Signature Series  Multi-vehicle  Synthetic  ATF continued providing superior protection for more than 180,000 miles  confirming its ability to provide reserve  protection.


The results of the field study  offer convincing proof of performance for fleets, contractors,  landscapers  and other commercial companies who operate work vehicles daily  in severe-service conditions.  The added protection of Amsoil synthetic lubricants  helps protect expensive  work vehicles from the negative effects  of extreme heat, especially  sludge formation,  helping to keep them on the job  making money.