I posted in April about Palm Beach Transit switching to nitrogen filled tires on their buses. The preliminary data has been analyzed, and the initial results appear promising:
Palm Tran, Palm Beach (Florida) County’s public transportation agency, has preliminary results from a nitrogen tire inflation trial on their bus fleet. Initial results, based on over the road analysis, have shown that nitrogen filled tires provided a 4.22% fuel efficiency improvement over their air filled counterparts. With Palm Tran’s fleet of 139 buses, this equates to a savings of over $400K at current diesel prices.
For this initial trial, fuel usage and mileage were recorded for 9 buses with nitrogen filled tires, determined their miles/gallon, and compared the results to historical air filled tire data for the same buses and the same routes. Neither the nitrogen filled tires nor the air filled tires were topped off during the trial, simulating the 2-3 month maintenance schedule common in large municipal and commercial fleets.
Palm Tran stresses that these are preliminary results, and more definitive long-term testing will begin on or about August 1st. These long-term tests will use telemetry devices that automatically measure tire temperature and fuel economy, and will be run over a six month time period. Tire and tread life improvements will also be analyzed during these tests.