Eaton Fuller 13-speed
The 10-speed with a splitter on the low range as well, giving finer control on grades and heavy loads. The classic owner-operator choice for anyone running mountains or heavy.
Torque rating
1650-2050
pound-feet at the input
Weight
760 lb
120 lb over the lightest, which is payload
Shifting
By hand
the driver decides the gear
Maker
Eaton
What it does to fuel
Better than a 10-speed on rolling terrain if the driver uses the splits, because it keeps the engine nearer its torque peak. Worse if they do not.
What this type is
A driver, a clutch and a stick. Cheaper to buy, cheaper to fix, lighter, and increasingly hard to sell: the used market for manuals has thinned as fleets standardised on automated boxes and as fewer drivers can shift one.
Known issues
The same clutch wear as the 10-speed, plus more to go wrong in the splitter air system.
Verdict
Worth the extra over a 10-speed for heavy haul and hills. Pointless for flat linehaul where you would use three of the thirteen.