(28 Dec 2014, 8:38 pm)DaveyBowyer wrote For the 17, Streetlites could be justified and despite the length of the route, the sections (with the exception of Burn Bank) aren't too demanding for the little 4.5l lump.
Considering Arriva's examples can handle the demanding 1-in-4 banks of Saltburn, Carlin How, Loftus and Lythe with ease - I think your argue of small engined vehicles falls short. As it's not the fuel capacity, it's the BHP (Arriva's Streetlites are 210bhp).