It’s all in the vote
Here I am comparing five engines in the 175 hp class – and wonder whether they are rightly leading a niche existence
The trend is towards outboard motors. Why? You are technically at eye level with those who do their work under the lid, i.e. under the sun lounger. In addition, they require less space compared to their installation counterparts, which means more storage space, and they also weigh less with the same performance – both of these advantages when driving.
In principle, however, the 175 hp engines play a subordinate role, as boats to which they can be attached are either only permitted up to 150 hp or up to 200 hp and more, and the difference in price for the engine between them is not too great .
In addition, the engines from 150 to 200 or 225 HP are almost identical and only differ from each other in the programming of the engine computer or in individual components. Or the 175 hp engine is even a throttled 200. One more reason to free the 175 hp engines from their shadowy existence and check what this class has to offer.
All the well-known manufacturers who have a 175 HP engine in their program were invited and also agreed: These are Evinrude, Honda, Mercury, Selva, Suzuki and Yamaha. The Selva model was delivered to the test site, but nobody showed up for assembly and coordination. We don’t know the reason.
From a technical point of view everything is represented: four- and six-cylinder engines as pure naturally aspirated engines or with supercharging, the cylinders of which are arranged in a row or V-shape and come with different displacement. Charging means that additional air is blown into the combustion chambers by means of a technical device such as an exhaust gas turbocharger or a mechanically driven compressor.
This means that the engine gets more air into the cylinders than by simply sucking in. As a result, an engine with less displacement can stand up to a naturally aspirated engine with more displacement. Because more air in the cylinder can be mixed with more fuel, which ultimately means more power. Of our test subjects, only the Mercury Verado works with charging (compressor).
But there are also differences in the way we work, where we are dealing with four-stroke and two-stroke engines. Evinrude is in the latter category. However, if you think of DKW cars or Trabants when you think of two-stroke vehicles and their sometimes visible plumes of exhaust gas, the working principle is correct, but not when it comes to emissions. The V6 Evinrude test engine plays in the very top league and does not need to hide from the four-stroke engines in any way. He is the top representative of what is technically possible today in the two-stroke class.
A Hellwig Milos V630 Cabin AB is available as a test boat, to which engines with an output of 150 hp to 225 hp can be attached. In our opinion, this boat and the 175 HP engines harmonize optimally, and it does not need more power, since we are already using the boat’s reserves a little, especially at top speeds. This has been slimmed down a bit, i.e. delivered without a rear seat bench, but otherwise everything corresponds to the standard equipment, such as the hydraulic control.
In order to create the same conditions for all test candidates, the boat was trimmed to the same weight again after each adjustment and test drive, i.e. the tank was filled with the amount of fuel that was used during the trips. In order to achieve comparable results, we drove every engine on the same main route in the same direction, and in the numerous acceleration measurements we took the one with the best values.
Each engine manufacturer installed its own engine on the boat and we gave us the time to coordinate it. It was part of the program that after the first test drive the engine was hung a hole higher or lower in order to finally attach one of the many propellers for the test.
Mercury, Suzuki and Yamaha tuned their engine with the intention of achieving good and more than satisfactory results in all areas (acceleration, fuel economy, sound pressure, speed). Honda, on the other hand, attached great importance to the best fuel economy, moderate sound pressure and not too high speeds without losing sight of speed. Evinrude made it easy and approached with the clear goal of being the fastest.
For athletes, the shoe creates the feeling of running and decides on the result or on victory and defeat. On boats this is the propeller; it consisted of stainless steel for all test candidates. Not only did our telemetry data show clear and interesting differences, how the power ultimately gets into the water and how the 175 hp were implemented in each case.
At least with the acceleration values, Yamaha stands out. If you look at the values at 10 km / h and 20 km / h, this also applies to Evinrude, whose propeller – the only one with acceleration openings on the hub – took noticeably longer, which is especially compared to speeds of 1500 to 2500 l / km RPM clearly visible.
As far as acceleration is concerned, Suzuki showed everyone involved how it’s done with its propeller-motor set-up. The engine accelerated the fastest from 0 to 70 km / h (8.85 s) and needed the shortest distance (103 m). Mercury is right behind with 10.48 s and 130.02 m. Honda beats Evinrude with 140.01 m with 138.32 m, even though both need the same time (11.37 s). Yamaha needed the biggest run-up with 164.62 m and 13.9 s.
In terms of top speed, all candidates exceeded the 80 km / h mark, which is impressive for this boat size. The front runner is Evinrude (85.7 km / h), followed by Yamaha (84.8 km / h). Then Honda and Mercury share the place on the podium (83.6 km / h). We recorded the lowest maximum speed at Suzuki with 81.1 km / h.
It is interesting to compare the respective speeds. At Yamaha there was a problem with acceleration, but not with the top speed, or in other words, the agony of choosing the propeller fell out in favor of the top speed, so that the engine reached a maximum of 5400 RPM at a permitted 5000 to 6000 RPM.
It took Honda the second longest to rev up; Here, the technicians decided to vote for the lower speed range with a permitted 5000 to 6000 rpm and left plenty of room for improvement with 5400 rpm. Evinrude (5000 to 6000 rpm), whose engine did not turn more than 5700 rpm, did not leave quite as much leeway. In contrast, Mercury (5800 to 6400 rpm) used the speed range almost completely up to a reserve of 100 rpm; Suzuki, on the other hand, (5500 to 6100 rpm) let its engine work up to the maximum speed at the top stop.
While Honda, Suzuki and Yamaha can only be driven with manual power trim – the driver presses the button on the gear lever himself – both Evinrude (standard) and Mercury (for an extra charge) offer an automatic power trim system. Both have programs that can be set in several stages or profiles for the respective boat and trim it to match, but also allow individual fine-tuning.
Evinrude used the general program for testing, which would have been a good fit for any normal boater. However, we did without it and trimmed it ourselves. Mercury, on the other hand, optimized its “Active Trim-Kit” during a very extensive test drive using a laptop.
We drove a medium level and the highest (also referred to as “aggressive trim”) and have to admit that the guys from Mercury did a great job on the test boat. But there is nothing like the tester’s sensitive thumb: Mercury just barely beat it (by 0.1 s!) In terms of acceleration values, but at the top speed he was able to pack on a good bit and show the electronics how and where it’s long.
If you look at the area in which the test boat is most economically on the move in fast planing, after evaluating our measurement data, we determine that it is between 3000 and 3500 rpm for all engines. With the Mercury this applies to both speeds; at 28.5 to 37.4 km / h it consumes 0.44 l / km each time.
Both speeds are also suitable for the Evinrude; he consumes 0.47 l / km at a speed of 34.7 km / h
or 42.8 km / h. With Suzuki it is 3000 rpm and 32.6 km / h, the consumption is only 0.42 l / km. At the same speed you drive 41.6 km / h with the Honda, while also only 0.42 l / km flow through the fuel line, and with the Yamaha you can achieve 38.6 km / h and a consumption of 0.43 l / km.
Assuming a tank capacity of 100 l, you theoretically get the furthest with the Suzuki (204 km), followed by Honda with 202 km, Yamaha with 196 km, Mercury with 192 km and Evinrude with 182 km – each plus 15% reserve.
If you look at the test candidates at the same speeds, you can see that the engines are close together and that sometimes one, sometimes the other, does better – apart from Evinrude, who, due to its propeller, can travel at 20 to 30 km / h or at 2000 to 2500 rpm shows higher values because it is a specially ventilated propeller.
As far as sound pressure is concerned, all test subjects remained below the 85 dB (A) limit up to 3500 rpm and above it from 4000 to 4500 rpm. The Evinrude engine alone begins to exceed this value from 2500 rpm.
Under the hood, all manufacturers use electronically controlled fuel injection. Also Evinrude, which, unlike its competitors, instead of intake manifold injection, does not blow the fuel in front of the intake valves, but directly into the combustion chamber.
Since Evinrude works on the two-stroke principle, it still “mists” oil on everything that moves in the engine block, even in the smallest doses. Important for Mercury: The engine must never be operated without an air filter, otherwise the compressor can be seriously damaged if something penetrates unfiltered.
While Honda and Yamaha command their representatives via conventional Bowden cables, the rest of the commands are given electrically or electronically – or in New German via “fly-by-wire””. When it comes to equipment with technical refinements, Evinrude takes a top position, followed closely by Suzuki and Mercury. Honda and Yamaha share third place on the podium.
An effective idle lock is provided by Honda, Mercury and Yamaha during the test. Suzuki manages without a lock and states that at high speeds the electronics first reduce it to 3000 rpm and in future to 2000 rpm before switching from full forward to reverse. It’s similar with Evinrude, except that, according to the manufacturer, the speeds are reduced to 1200 rpm before the shifting process continues.
There are also differences in the underwater area. Except for Suzuki and Evinrude, where the gears are shifted electrically, all engines have conventionally shifted transmissions. And with Suzuki all you have to do is turn a plug to turn the propeller clockwise or anti-clockwise, which makes double installation easier; you just have to buy a suitable propeller.
All engines are steered with the hydraulic controls built into the boat as standard. The only exception: Evinrude – with it you don’t need the control cylinder, but connect the hydraulic hoses directly to the engine, as it has an integrated power steering as standard.
It is state of the art that alarm systems are used by all manufacturers, which are noticeable in the event of malfunctions with an acoustic or optical signal and, in an emergency, allow the engine to continue running with an emergency program.
As far as the guarantee is concerned, all manufacturers offer three years, some also offer special regulations. With Suzuki, free mobility protection is included in the three-year warranty period. At Honda, the entitlement can be extended for a further two years for a fee, Mercury offers two years and allows three years extension at no extra charge if the customer can prove and register the required service.
If you put the weight values, the placements in the individual categories plus the state of the art, the price and the guarantee regulations in one pot, you see Suzuki in first place, closely followed by Mercury in second place. Third place in the overall number of points is shared by Honda and Yamaha, while Evinrude takes fourth place – with the latter leading in both top speed and state of the art.