The Riviera 545 SUV 2020 vs Riviera 645 SUV 2021 comparison sits squarely in the category of decisions where specs alone won't tell the whole story — intended use, storage, and long-term ownership costs all factor in.
Size is the most obvious dividing line here. The Riviera 645 SUV 2021 measures 69,8 feet overall (2021), giving it roughly 12,7 additional feet of deck space compared to the Riviera 545 SUV 2020 at 57,1 feet (2020). Weight tells a clearer story for trailering families: the Riviera 645 SUV 2021 tips the scales at 88 119 lbs — 35 462 lbs less than the Riviera 545 SUV 2020 at 52 657 lbs. That difference is meaningful if you're working within a half-ton or three-quarter-ton truck's tow rating, especially once you factor in a motor, gear, and fuel.
The power gap is worth calling out. Rated to 1 300 hp, the Riviera 645 SUV 2021 has a 575-hp advantage over the Riviera 545 SUV 2020's 725-hp ceiling — enough to notice on acceleration and at cruising speed, particularly with a full passenger load. Fuel capacity breaks the other way: the Riviera 645 SUV 2021 carries 1 717 gallons versus 925 gallons in the Riviera 545 SUV 2020. On a lake day that's negligible, but for coastal cruising or long reservoir runs the extra range matters.
For family outings this is probably the sharpest distinction between the two. The Riviera 645 SUV 2021 is rated for 21 passengers, while the Riviera 545 SUV 2020 caps at 17. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Riviera 645 SUV 2021 could be the deciding factor.
Bottom line: Choose the Riviera 645 SUV 2021 if your priority is putting more people on the water — it handles 21 passengers and at 69,8 ft it has the deck room to back that rating up comfortably. The Riviera 545 SUV 2020 is the smarter pick if you want a lighter, easier-to-trailer boat rated for 17 that costs less to run day-to-day.