Few applications place more stress on lubricants than taxi cabs, particularly those operating in the desert heat of Las Vegas, Nev. The combination of excessive idling, stop-and-go driving and high ambient temperatures creates the ideal scenario for lubricant failure, resulting in sludge formation and catastrophic component failure.

AMSOIL INC. recently initiated a field study designed to show the performance and protection capabilities of AMSOIL Signature Series Synthetic Automatic Transmission Fluid and AMSOIL Signature Series Motor Oil. The products were installed in six of the fleet’s vehicles with oil change intervals of 1,005 hours (the equivalent of 15,000 miles) in average ambient temperatures of 100oF. Transmission fluid was not changed in any of the vehicles. The aim of this field study was to demonstrate how AMSOIL synthetic lubricants resist breakdown, minimizing wear and sludge in the most demanding circumstances.

The Las Vegas taxi company selected for this field study had been previously experiencing rampant engine failures using a synthetic blend motor oil changed every 5,000 miles. The severity of service also required transmission fluid changes every 20,000 miles. The engine failures they had previously been experiencing occurred predominantly during hot summer months due to excess sludge clogging the oil pickup tubes resulting in oil starvation.

The field study was broken into two parts. Part one assessed the performance of Signature Series Multi-Vehicle Synthetic ATF. Part two focused on how the motor oil held up.

At the end of the test period, a 2010 Dodge Charger equipped with a 2.7L V6 engine and a 4-speed automatic transmission (model #42RLE) was removed from service for teardown and analysis. After being exposed to severe service conditions and extending drain intervals to 15,000 miles, the engine components were virtually sludge free and suitable for continued use. Though the transmission service life had been extended to five times that which the taxi cab maintenance team previously used, the components were in remarkable condition. (Photos of the components appear in the study.)

In addition to component analysis, the used transmission fluid was also analyzed. Results confirmed that the fluid was able to provide reserve protection in transmissions during severe service conditions.

Bottom Line: AMSOIL Signature Series Synthetic Motor Oil provided excellent protection throughout extended drain intervals. After accumulating 7,033 hours of service (102,582 miles) the AMSOIL Synthetic Signature Series Transmission Fluid remained suitable for continued use.

To receive a free copy of this study visit www.amsoil.com/performancetests.aspx or contact info@amsoil.com.