The Princecraft Platinum SP 186 SE 2005 vs Princecraft Xpedition 170 SC 2012 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 - Princecraft Platinum SP 186 SE 2005 at 18,0 ft versus Princecraft Xpedition 170 SC 2012 at 16,9 ft. Weight tells a clearer story for trailering families: the Princecraft Platinum SP 186 SE 2005 tips the scales at 1 399 lbs - 344 lbs more than the Princecraft Xpedition 170 SC 2012 at 1 055 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 175 hp, the Princecraft Platinum SP 186 SE 2005 has a 60-hp advantage over the Princecraft Xpedition 170 SC 2012's 115-hp ceiling - enough to notice on acceleration and at cruising speed, particularly with a full passenger load. Fuel capacity breaks the other way: the Princecraft Platinum SP 186 SE 2005 carries 60 gallons versus 20 gallons in the Princecraft Xpedition 170 SC 2012. 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 Princecraft Platinum SP 186 SE 2005 is rated for 8 passengers, while the Princecraft Xpedition 170 SC 2012 caps at 5. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Princecraft Platinum SP 186 SE 2005 could be the deciding factor.
At this size, power-to-weight ratio matters more than outright horsepower. The Princecraft Platinum SP 186 SE 2005 comes in at 8 lbs per hp versus 9 lbs per hp for the Princecraft Xpedition 170 SC 2012. 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 Princecraft Platinum SP 186 SE 2005 if your priority is putting more people on the water - it handles 8 passengers and at 18,0 ft it has the deck room to back that rating up comfortably. The Princecraft Xpedition 170 SC 2012 is the smarter pick if you want a lighter, easier-to-trailer boat rated for 5 that costs less to run day-to-day.