harry:
Swiss was always 10hp per ton. For TIR it was mostly 350hp in the old days but I’ve seen the latest Topline V8’ chassis & trailer tippers hauling cobbles with dinky little bodies grossing 28t.
A 290 Saurer would be well on top of its job then 
A smidgen over the top for rainy days.
generally it’s 10bhp per ton.
in switzerland it’s 12bhp per ton.
We had 350 engines as standard since way back in Swiss for TIR. I used to gross 37t with a wagon & drag coming up from Spain thru Germany to Swiss when the UK lads were running 32t gross. Never told ‘em otherwise they would make a song & dance about it. They used to sit in Muttenz & say.’ But why do you need 350 horse when your weight limit is 28t gross?’ Well now you know the answer. I crossed Swiss to Germany 2/3t overweight & the cop put me on the weighbridge. He kept me 30mins then came out & warned me.‘Don’t do it again!’ Gave me my docs & waved me on my way. The Swiss used to be treated well by the German zoll:lol:
Another trick was to take a trailer across the border for delivery in Germany without a permit. They asked for the permit but we just said we were dropping the trailer on the German side of the border. Drop the trailer ,return to Swiss ,later return bobtail ,pick up trailer & off to Hamburg. Horses for courses. You would never get away with that in France but as I say the Germans had a soft spot for the Swiss.