X15 questions

[Camstyn]

Thanks for the feedback. I don’t think I could get away with a single axle tractor, I need all the traction I can get. An aero day cab may be in my future though, I’ll have to rent one again for more than one trip to verify the results that I found.

I guess my biggest question is since I get the same MPG’s at 565/2050 and 505/1850 with my performance series, would I see better numbers with an efficiency series at 500/1850, all else being equal? I’m not using all of it anyways so I wonder if there is anything hidden in the differences between the two engines that would actually net me better results, or if it would just be the same with less power on tap in reserve. I would normally assume so but was surprised how efficient my rental with the performance series at 525/1850 was. It was not full aero but did have cab and roof fairings, and 46k rear axles. Heavy haul truck. I could spec a similar truck with regular 40’s, weed burner exhaust, disk brakes, lower chassis side fairings etc to make it lighter and more aero yet.

Has anyone experimented with both a performance and efficiency series doing the same job to see if the efficiency is actually more efficient, or if it’s just slower?