Eaton's XFE 75W-80 axle lubricant is a fully synthetic axle lubricant meant to help increase fuel efficiency and maintain durability across heavy-duty applications. An OE-approved formulation, the lubricant can be used in axle applications under warranty for both linehaul and vocational trucks, and according to the company, Mesilla Valley Transportation Solutions found that XFE 75W-80 provided up to 2% improvements in fuel economy compared to standard axle lubricants.