The Bennington 165 Si 2005 vs Bennington 1850SF 2009 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.
On paper these two are close siblings in the size department — Bennington 165 Si 2005 at 16,0 ft versus Bennington 1850SF 2009 at 18,0 ft. Weight tells a clearer story for trailering families: the Bennington 1850SF 2009 tips the scales at 1 611 lbs — 236 lbs less than the Bennington 165 Si 2005 at 1 375 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.
Both boats share a closely matched power ceiling — 50 hp for the Bennington 165 Si 2005 and 60 hp for the Bennington 1850SF 2009. Real-world performance will come down more to which motor is actually bolted on, its load at the time, and whether it's a 4-stroke or 2-stroke setup.
For family outings this is probably the sharpest distinction between the two. The Bennington 1850SF 2009 is rated for 23 passengers, while the Bennington 165 Si 2005 caps at 7. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Bennington 1850SF 2009 could be the deciding factor.
At this size, power-to-weight ratio matters more than outright horsepower. The Bennington 1850SF 2009 comes in at 27 lbs per hp versus 28 lbs per hp for the Bennington 165 Si 2005. The lower the ratio the more explosive the acceleration — meaningful on a short RIB where bursts of speed, quick planing, and agility in surf or tight waterways define the experience.
Bottom line: Choose the Bennington 1850SF 2009 if your priority is putting more people on the water — it handles 23 passengers and at 18,0 ft it has the deck room to back that rating up comfortably. The Bennington 165 Si 2005 is the smarter pick if you want a lighter, easier-to-trailer boat rated for 7 that costs less to run day-to-day.