When two boats share the same hull type — in this case both the Sundance K16FLX 2008 and the Sundance SV186 2011 are modified vee designs with fiberglass construction — the buying decision usually comes down to a handful of practical questions: how many people are you putting on the water, how far do you trailer, and what does your tow vehicle weigh?
Size is the most obvious dividing line here. The Sundance SV186 2011 measures 18,5 feet overall (2011), giving it roughly 3,5 additional feet of deck space compared to the Sundance K16FLX 2008 at 15,0 feet (2008). At 72 lbs and 145 lbs respectively, both sit in a similar weight class — either should pair comfortably with most mid-size SUVs and half-ton trucks, though always confirm your specific tow rating with the motor added.
The power gap is worth calling out. Rated to 150 hp, the Sundance SV186 2011 has a 100-hp advantage over the Sundance K16FLX 2008's 50-hp ceiling — enough to notice on acceleration and at cruising speed, particularly with a full passenger load. Fuel capacity breaks the other way: the Sundance K16FLX 2008 carries 11 gallons versus 4 gallons in the Sundance SV186 2011. 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 Sundance SV186 2011 is rated for 5 passengers, while the Sundance K16FLX 2008 caps at 4. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Sundance SV186 2011 could be the deciding factor.
Bottom line: Choose the Sundance SV186 2011 if your priority is putting more people on the water — it handles 5 passengers and at 18,5 ft it has the deck room to back that rating up comfortably. The Sundance K16FLX 2008 is the smarter pick if you want a lighter, easier-to-trailer boat rated for 4 that costs less to run day-to-day.