It's torque you need to get you up the hills and as said you have to maybe
drop down a cog.
My van has a huge 88 BHP the GVW is 6.6tonnes and is rated 10tonne max.
trainweight, 8.8BHP per tonne....pathetic!
I generally run @ around 5tonnes..... 88BHP and 284Nm torque @ 1400 to 2200 rpm
is enough get me up any hill I've ever encountered because it has reasonable torque and low
gearing to match, very rarely drop below 3rd gear. But it's slow progress.
Mind you I don't reckon I would ever really think running fully loaded
with a 3.5tonne trailer (10tonnes) would be practical in the real world.:scared: