looking at vesta, allegra breeze, or newmar ventura . want to make sure engine good for weight of rv. would like to tow two motorcycles about 1300lbs. my dad bought a rv with a bigger engine and was much happier than his first rv.
The rule of thumb for motorhome engine power is a 100 lbs/hp, and anything to be towed should be included in the weight. That will give you adequate performance but still a bit slow on steeper hills, so if you want stronger performance you should drop that ratio to something like 80 lbs/hp. If it's a gas engine RV, remember that the rated horsepower comes only at high RPMs, so if you don't want the engine to be "screaming" on steep grades, keep the weight/hp ratio as low as possible. That won't be an issue with a diesel.
The Vesta has 300 hp and a GVWR of 29,000 (max 33,000 combined with toad or trailer). You may not be loaded to max, but that is pushing the top of the rule-of-thumb. The Allegro Breeze is similar, with 240 hp and GVWR of 22,000 or 23,500 (depending on length) and a GCWR of 26,000 or 28,000.
I'm guessing you meant the Newmar Ventana rather than Ventura? Ventana have a bigger engine but heavier weights too. 360 or 380 hp and GVWR of 32k or 44k and GCWRs to42k or 54k. With the Ventana, yo would be well under the GCWR and probably under the GVWR as well, so it's probably your best bet of the three.
I started with 3 gas rigs and now have a diesel pusher. What a difference, power, ride, BRAKES, and quiet up front without any engine heat. Never go back. Mileage now up to 9.7 MPG towing my 22' enclosed trailer with toys in it. Over 100,00 miles and running better. Skip the learning curve and white knuckle experiences and go Diesel Pusher. MY Opinion