We had to settle it right from the start. Everyone wanted to know if stern drives are faster. And, for once, the boatyard rumors were right - stern drives fly. The 260-hp stern drive boat ran 47.1 mph at 4600 rpm, while the 260-hp V-drive hit only 34.5 mph. No one expected that much of a difference. The 300-hp V-drive did a little better at 38.2 mph.
CERTIFIED TEST RESULTS: 260-hp V-drive. Advertised fuel capacity 230 gallons. Range based on 90 percent of that figure. Performance measured with two persons aboard, half fuel, no water. Sound levels measured at helm, in dB-A.
TEST POWER: Twin 260-hp MerCruiser 5.7L V-8 gasoline inboards with 350 cid, 4.00" bore x 3.48" stroke, swinging
PRICE: $124,080 Of more real-world importance on a boat like the 290 Amberjack is fuel consumption. At wide open throttle it was about the same for all three boats. But when comparing fuel consumption at the same speeds, the stern drives again had a decided advantage. The stern drive ran 34.7 mph at 3500 rpm, pretty much the same as the 260-hp V-drive's 34.5-mph top speed. In terms of fuel consumption, the stern drives burned only 22.8 gph at 3500 rpm versus the V-drive's 40 gph at WOT. At 4000 rpm the stern drive boat hit 39.4 mph and consumed 25.2 gph - about 1 mph faster than the 300-hp V-drive's top end, which ate 40.6 gph at the same rpm. Those numbers equal big advantages in speed and economy. And the advantage goes to the stern drive.
During our planing tests, however, the 300-hp 350 MAG MPI Horizon V-drives came through - the boat planed in 5 seconds flat whether we used trim tabs or not. The 260-hp stern drives got the boat on plane in 6 seconds with the tabs down and in 6.5 seconds with them up. Not far behind were the 260-hp V-drives, which took 6.8 seconds tabs down, and 7.2 tabs up.
CERTIFIED TEST RESULTS: 300-hp V-drive. Advertised fuel capacity 230 gallons. Range based on 90 percent of that figure. Performance measured with two persons aboard, half fuel, no water. Sound levels measured at helm, in dB-A.
TEST POWER: Twin 300-hp MerCruiser 350 MAG MPI Horizon V-8 gasoline inboards with 350 cid, 4.00" bore x 3.48" stroke, swinging 17" x 15" three-bladed Nibral props through ZF 63-IV V-drives with 1.5:1 reductions.
The added grunt of the 300-hp V-drives helped make up for the stern drive's ability to match its trim to the boat's speed. From 3500 rpm to top end, the 300-hp V-drive boat ran at the same angle as the stern drive boat when trimmed for optimum efficiency. By comparison, the 260-hp V-drive boat rode with a more bow-high attitude.