Truck Conversion & Toterhome Community - View Single Post - Comments wanted: 2000 Freightliner/Trendsetter 26'.

James · 05-20-2005, 01:02 AM

The price isn't bad for the conversion. However, the auto trans kills it for me.
For fuel econ you want to keep the rpms in a narrow band, 1200 on the low end and 1600 up high. The 6 speed, IIRC has an 800rpm band between shifts. That's out of the sweet spot by 200rpm's at both ends of the shift.
The 10speed UltraShift can keep you in that 400rpm sweet-spot. The 12speed ZF has a slightly tighter band.
Plus, the Ultra and the ZF are both lighter than the Allison and both require less maintenance.

05-20-2005, 01:02 AM	#2
James Junior Member Join Date: Jun 2003 Location: Oklahoma City, OK, US of A Posts: 27	The price isn't bad for the conversion. However, the auto trans kills it for me. For fuel econ you want to keep the rpms in a narrow band, 1200 on the low end and 1600 up high. The 6 speed, IIRC has an 800rpm band between shifts. That's out of the sweet spot by 200rpm's at both ends of the shift. The 10speed UltraShift can keep you in that 400rpm sweet-spot. The 12speed ZF has a slightly tighter band. Plus, the Ultra and the ZF are both lighter than the Allison and both require less maintenance.