The Jeanneau Leader 40 2019 vs Jeanneau Sun Fast 31 1990 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 Jeanneau Leader 40 2019 measures 40,5 feet overall (2019), giving it roughly 15,1 additional feet of deck space compared to the Jeanneau Sun Fast 31 1990 at 25,4 feet (1990). Weight tells a clearer story for trailering families: the Jeanneau Leader 40 2019 tips the scales at 16 603 lbs — 9 769 lbs more than the Jeanneau Sun Fast 31 1990 at 6 834 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 300 hp, the Jeanneau Leader 40 2019 has a 282-hp advantage over the Jeanneau Sun Fast 31 1990's 18-hp ceiling — enough to notice on acceleration and at cruising speed, particularly with a full passenger load. Fuel capacity breaks the other way: the Jeanneau Leader 40 2019 carries 96 gallons versus 13 gallons in the Jeanneau Sun Fast 31 1990. 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 Jeanneau Leader 40 2019 is rated for 12 passengers, while the Jeanneau Sun Fast 31 1990 caps at 7. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Jeanneau Leader 40 2019 could be the deciding factor.

Displacement is where these two sailboats genuinely part ways. The Jeanneau Leader 40 2019 displaces 16 603 lbs — a 9 769-lb difference over the Jeanneau Sun Fast 31 1990 at 6 834 lbs. That gap separates two entirely different categories of sailing: the heavier boat is built for offshore passage-making and load-carrying, while the lighter hull rewards performance sailing and easier handling in lighter air.

Draft is a practical consideration that many buyers underestimate until they're already at the marina. The Jeanneau Sun Fast 31 1990 draws 5,8 ft, compared to 3,7 ft for the Jeanneau Leader 40 2019. That 2,1-foot difference affects which anchorages you can access, which haul-out facilities will take you, and how carefully you need to read the tide tables in shallower cruising grounds.

For auxiliary power the Jeanneau Leader 40 2019 carries a 300-hp engine against 18 hp on the Jeanneau Sun Fast 31 1990. Motoring range and ability to punch through a foul current or enter a tight marina under power will favour the more powerful installation.

For extended cruising, water capacity matters: the Jeanneau Leader 40 2019 carries 65 gallons versus 26 gallons on the Jeanneau Sun Fast 31 1990 — a significant advantage on longer passages where watermaker or provisioning stops aren't guaranteed.