When two boats share the same hull type — in this case both the Starcraft Marine 170 Sport 2010 and the Starcraft Marine 191 IO 2008 are modified vee designs with aluminum 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?

On paper these two are close siblings in the size department — Starcraft Marine 170 Sport 2010 at 16,8 ft versus Starcraft Marine 191 IO 2008 at 19,0 ft. Weight tells a clearer story for trailering families: the Starcraft Marine 191 IO 2008 tips the scales at 1 532 lbs — 437 lbs less than the Starcraft Marine 170 Sport 2010 at 1 095 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 140 hp, the Starcraft Marine 170 Sport 2010 has a 137-hp advantage over the Starcraft Marine 191 IO 2008's 3-hp ceiling — enough to notice on acceleration and at cruising speed, particularly with a full passenger load. Both carry nearly identical fuel loads — 32 gal and 34 gal — so range won't be a tiebreaker here.

For family outings this is probably the sharpest distinction between the two. The Starcraft Marine 191 IO 2008 is rated for 8 passengers, while the Starcraft Marine 170 Sport 2010 caps at 6. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Starcraft Marine 191 IO 2008 could be the deciding factor.