Cruisers 400 Express Page 3
400 Express — By Capt. Bill Pike —
Sometimes, Less Is More
Inboard Power—A Radical New Step
PMY test drove Cruisers Yachts’ 400 Express several months ago with 272-hp Volvo Penta D6-370 diesels and Volvo’s Inboard Propulsion System (IPS), a wild new approach to inboard power. It has forward-facing propellers (highly efficient by comparison with conventional inboards because they operate in water undisturbed by struts, etc.); a massive, steerable, underwater unit of nickel-aluminum-bronze alloy that’s sealed and vibration-damped with thick, rubber O-rings; electronic/electric (as opposed to hydraulic or mechanical) steering; and the complete integration of exhaust, water-intake, engine control, and steering functions into one fast-install envelope.
The driving experience? Capt. Bill Pike was impressed with the tight-turning radius and the acceleration of the cutting-edge 400 as well as the seeming extra top end. Based on in-house testing, Volvo Penta reports speed increases of 20 percent from IPS and fuel economy improvements of 30 percent by comparison with conventional vessels. Thanks to Pike’s extended test drive, he thinks these numbers, when independently verified, may prove conservative. Moreover, although initially flummoxed by the exceptional low-end oomph of the units (especially when backing down) as well as the fast action of the electronic/electric steering, Pike says he’s sold on IPS for dockside maneuvering.
PMY’s been following IPS for six years, beginning when the unit sported a rudder instead of steerable props and no safe-breakaway feature to address the issue of hard groundings. To accurately validate our accumulated impressions—and the data reported by Volvo Penta— PMY and Cruisers Yachts put together a testing shootout some weeks ago between a conventional Cruisers 400 Express and another 400 that was virtually identical, except for various IPS-related modifications. Results, along with a full explanation of IPS, will appear in PMY’s February issue. —G.L.P.
This article originally appeared in the December 2004 issue of Power & Motoryacht magazine.