Tractor test: Valtra T191 Not even the most devoted of Valtra fans would describe the firm’s S-series high-hp range as a runaway sales success – to the extent that it has largely been left to the upper-end T models to fly the Finnish tractor flag, a role that it has now undertaken in various guises for over a decade. Here we test the latest incarnation, the Tier III 136kW/185hp Valtra T191