When the 90's and 110s were first introduced we had terrible trouble with the new (diesel) engines - and all sorts of shenanigins were undertaken as the "blame" rocked back and forth between LR and MOD. No fewer than 6 variants of the engine were tried and eventually under an initiative called Op Terry we got to test the latest version - all 55bhp of it. We trialled a fully laden FFR with a 3/4 ton trailer, all up weight of the whole thing 3.5 tonnes. It reached 30mph in 30 seconds (unless you turned right up Queens Avenue in which case you didn't get to 30mph) and pulling out at every road junction was a heart-in-mouth gamble.
After that the MOD bought a load of V8s as a stop gap, plus we naughty boys in the user trials organisation started using disgusting words like Pinzgauer in polite conversations....
So even with a better power curve than the Mk6 Terry engine theoretical towing weight is one thing, the reality of taking something with a big anchor on the back onto HM's highways (safely - and by that I mean being able to accellerate as well as brake) needs careful thought.
As an aside LR insisted that their engine was excellent as witnessed by the fact that it was fitted to virtually every London Taxi in existence. We checked with the cabbies who nearly choked on their bacon sarnies before saying exceptionally colourful things about that particuar engine (and the benefits of repowering with Isuzu)