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Location: Rhinelander, Wisconsin | Bass and Walleye Boats Article: Put Up or Shut Up
It’s a two-stroke vs. four-stroke showdown among Mercury, Suzuki and Yamaha
By John Tiger, Jr.
Bass and Walleye Boats
June 30, 2006
'Editor Steve Quinlan and I met with the very accommodating folks from Ranger Boats on Arkansas’ Bull Shoals Lake in mid-spring, and conducted a shootout between 250-horsepower offerings from all of the major players (sans Evinrude, who was invited but declined) on identical Ranger 620VS multispecies boats. We had at our disposal for the weekend four four-strokes (a Suzuki DF250, Yamaha F250, and Mercury 250 Verado) stacking the deck against a lone two-stroke DFI (Mercury 250XS). With four outboards comparing very closely in terms of weight, horsepower output, top-end rpm limits and torque, we expected the outcome to be pretty close. With the exception of the top speed and acceleration of the Mercury 250XS, it was.'
'SPEED AND PUNCH: TWO-STROKE BRAGGING RIGHTS
No sense dancing around it, in terms of speed and acceleration, Mercury’s 250XS is clearly the champion of the 250-horsepower crowd -- and by a very significant margin. We hit a best average top speed of 64.5 mph spinning a 24-inch-pitch lab-worked Bravo I four-blade wheel right at the limiter (5850 rpm). We actually bumped the limiter a few times, trimming high into the wind while trying to eke out that last mph. The next closest speed was achieved by the Verado, at 63 mph even (turning a 23-inch lab-finished Tempest Plus propeller) at 6140 rpm. The Yamaha finished third with a solid 60-mph clocking, turning a stock 23-inch-pitch Yamaha VX-Max three-blade prop at 6000 rpm. In the top speed wars, the Suzuki came up fourth out of the four, pushing the Ranger to 58.6 mph at 6100 rpm turning a stock Suzuki 16x24.5-inch three-blade prop.
We must note, however, that Suzukis traditionally like to be run high. After some preliminary prop testing, Senior Product Development Engineer David Greenwood raised the engine to the very top set of holes (3/4-inch higher than any of the other three engines) and said he was disappointed he couldn’t raise it any higher. He noted after his test runs that the engine never really felt like it had broken loose at that height.
Acceleration results put the two-stroke XS at the top of the pile, too. Merc’s raspy “race production” engine pushed the stout Ranger to 30 mph from a dead stop in 6.2 seconds, a full four-tenths of a second quicker than the second place finisher (again the Verado, at 6.6 seconds). The Suzuki came in a very close third this time, with a 6.7-second clocking, and the Yamaha pulled up fourth with a distant 7.7-second average.
Midrange punch (measured in seconds from a 30-mph cruise to 50-mph) told a slightly different story. Here’s where the XS really put the smackdown on the others; it romped from 30 to 50 in 6 seconds flat, where the next closest competitor (Verado) could only muster an 8.1-second clocking. The Yamaha’s midrange torque topped the Suzuki’s, as it finished a full second (8.3 vs. 9.3) ahead to finish third. To those doubting Thomases, we used no fewer than four (!) methods of speed measurement: two handheld Garmin GPS 12 units, a boat-mounted Lowrance GPS (which was a delight to use, by the way) and a calibrated Stalker Pro k-band handheld radar speed gun. For rpm readings, we used our own digital FloScan tach for all of the engines.'
'FUEL ECONOMY: SURPRISE!
No surprise to us at /BWB/ but probably a disappointment to tree-huggers everywhere, the two-stroke Mercury 250XS eked out a win in the fuel-economy challenge, too. With an average of 3.5 mpg across the entire rpm range, it bested the Suzuki by one-tenth of a gallon. The Yamaha came in a close third at 3.2 mpg, and the absolutely thirsty Verado finished a distant fourth with a 2.8 mpg average.
With today’s fuel prices, this is a critical part of the test. We ran these numbers several times to be sure, and came up with the same results each time. We also checked our results against Yamaha’s and Mercury’s factory digital fuel-flow meters.
While the 250XS took top honors for overall average fuel economy, the Suzuki 250 actually achieved the highest mpg recording at cruise speeds. With a 4.3 mpg recording at 24.7 mph and 3000 rpm, it bested Merc’s XS by a tenth of a mpg at the same rpm.'
'FINAL OBSERVATIONS
Clearly, four-strokes have a long way to go yet in the top speed, acceleration and even the fuel-economy wars before they can catch a well-tuned DFI two-stroke like Mercury’s 250XS. It’s a shame we didn’t have Evinrude’s 250 E-Tec in the mix to compare — they were very conspicuous in their absence. In addition, Yamaha has since last season discontinued the 25-inch Saltwater Series version of their vaunted VMax 250 HPDI, so we sorely missed their two-stroke participation in this test. Perhaps in the future we’ll do another two-stroke/four-stroke 250 shootout — on a bass boat — among 20-inch-shaft engines. '
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There is more out there about this issue, look for it and you will find like articles. I see this regularly on the Walleye trails out there; simply put the actual on the water fuel economy seems to be better with the DFI Two Strokes, especially the Mercury.
From what I have read, the DFI Evinrude is the hardest two stroke on fuel, but not by what would be considered a terrible amount.
Also consider the weight/power ratio, time to plane, etc. That's why at the end of the day there is more gasoline in the tank of some DFI two stroke powered rigs than a comparable boat powered by a 4 stroke; even one from the same engine builder.
What does this mean to the buyer? it's only a portion of the buying decision, but reading this article and others like it send me back to my OptiMax. Speed, acceleration, and fuel economy offset the noise and need to fill that oil tank. Paying for maintenance on the four strokes can offset the oil costs in a DFI, check the numbers.
Would I buy a Mercury, Yamaha or Suzuki 4 stroke V6 outboard? If I was a general consumer looking for a 4 stroke because of the features and benefits, sure. But, I'd gather all the facts first.
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