When two boats share the same hull type — in this case both the Alumaweld Intruder Sterndrive 18 2008 and the Alumaweld Intruder Sterndrive 20 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?
Size is the most obvious dividing line here. The Alumaweld Intruder Sterndrive 18 2008 measures 18,0 feet overall (2008), giving it roughly 16,0 additional feet of deck space compared to the Alumaweld Intruder Sterndrive 20 2008 at 2,0 feet (2008). Weight tells a clearer story for trailering families: the Alumaweld Intruder Sterndrive 18 2008 tips the scales at 1 955 lbs — 1 729 lbs more than the Alumaweld Intruder Sterndrive 20 2008 at 226 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 — 220 hp for the Alumaweld Intruder Sterndrive 18 2008 and 225 hp for the Alumaweld Intruder Sterndrive 20 2008. 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. Fuel capacity breaks the other way: the Alumaweld Intruder Sterndrive 18 2008 carries 47 gallons versus 6 gallons in the Alumaweld Intruder Sterndrive 20 2008. 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 Alumaweld Intruder Sterndrive 20 2008 is rated for 6 passengers, while the Alumaweld Intruder Sterndrive 18 2008 caps at 5. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Alumaweld Intruder Sterndrive 20 2008 could be the deciding factor.
At this size, power-to-weight ratio matters more than outright horsepower. The Alumaweld Intruder Sterndrive 20 2008 comes in at 1 lbs per hp versus 9 lbs per hp for the Alumaweld Intruder Sterndrive 18 2008. 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 Alumaweld Intruder Sterndrive 20 2008 if your priority is putting more people on the water — it handles 6 passengers and at 2,0 ft it has the deck room to back that rating up comfortably. The Alumaweld Intruder Sterndrive 18 2008 is the smarter pick if you want a lighter, easier-to-trailer boat rated for 5 that costs less to run day-to-day.