- In practice, Suzuki tend to play the good-value-for-money card by coming in with lower prices than their main rival.
- … it is exceptionally quiet, with hardly any discernible vibration at tickover and low speeds.
Robert Greenwood reports on Suzuki’s new big inline four-cylinder outboard, which shows that it can more than match V configuration and inline sixes.
Petrol engines have started to punch above their weight in recent years. There’s a new generation of smaller, lighter blocks that are altering our perception of what petrol burners can achieve. These bantamweights not only have better power-to-weight ratios that outstrip the middle- or even heavyweight units of 10 years ago, but they can also deliver equal, or even superior, performance with less fuel consumption, lower emissions and fewer decibels.
The trend has been most obvious in the car market, where, for example, Ford and more recently General Motors have launched three-cylinder engines of just below 1000cc that are capable of pushing out up to 125hp – the kind of output we would have expected from two-litre engines not so long ago, but with much heavier fuel consumption and far dirtier exhausts.
Similar things have been happening with outboard motors. A new benchmark was set at the upper end of the power spectrum when Yamaha announced their 200hp, four-cylinder, four-stroke outboard, the F200, which could do the job of a similarly rated V6, but do it better in terms of overall engine efficiency. That was at the end of 2012, with the model becoming available globally in spring 2013. Now, over a year later, Suzuki, Yamaha’s main rival today in the European outboard market, have set out directly to challenge this model with their own 200hp, four-cylinder, four-stroke model, the DF200A.
A cursory look at the spec sheets for both outboards shows them to be broadly similar. Both have 16-valve double overhead camshaft powerheads of around 2.8 litres displacement, multi-point sequential fuel injection and long-track air intake systems, all of which help to optimise engine breathing. There’s no radically new engineering involved. It’s more a matter of evolutionary development, but they all add up to an important overall advance in outboard technology that has created a new niche in the market that has the potential to undermine today’s top-powered production models.
Suzuki’s new DF200A is largely based on their recently introduced 175hp model, the DF175A, and goes on sale at the end of this year. Its lively performance, with reduced fuel consumption plus quiet and smooth operation, should win it many friends. Performance with economy is due to a number of engineering features. First, it’s a considerably lighter outboard than the Suzuki V6, although packing a similar punch. Despite its big-block displacement of 2867cm³ it weighs 31kg, or 12 per cent, less than its older V6 sibling. A high compression ratio of 10.2:1 compresses the fuel/air mixture with nearly 10 per cent more force, while the air drawn into the engine has already been condensed by cooling. A semi-direct air intake system, incorporating special baffling, delivers cooler air directly to the engine’s long-track tuned intake manifold. That’s aided by Suzuki’s proven VVT (variable valve timing) system with four valves per cylinder – all this resulting in a 1.2 per cent improvement in top-end speed and a 0–50 m acceleration improvement compared with its nearest competing models, according to the company’s own test results.
Lower fuel consumption, meanwhile, is helped by Suzuki’s familiar Lean Burn control technology. This operates through its 32-bit on-board ECM (electronic control module), which takes its input from engine sensors from engine timing and O2 levels to ambient temperature in order to provide the precise amount of fuel needed throughout the RPM range.
Another sensor monitors engine knock and ‘listens’ to combustion, providing information for the ECM (electronic control module) to precisely manage engine timing for smoother running. The outboard’s good manners are helped by Suzuki’s counter-balancer system, which irons out secondary vibration at high operating speeds – a problem to which some inline four-cylinder engines can succumb – by countering piston movement. Further vibration dampening is provided by the manufacturer’s thrust mount system, which combines soft rubber mounts to absorb vibration at idle, and high-thrust rubber mounts that do the same under high loading.
So how well does this engineering package work in practice? Ahead of the DF200A’s market launch at winter boat shows, PBR had a brief taster of it on Lake Geneva in late November. The first thing you notice when setting out from the dock is that it is exceptionally quiet, with hardly any discernible vibration at tickover and low speeds. We have become used to quieter outboards generally since the advent of four-stroke outboards 15 or so years ago, but with this one you could almost be forgiven for mistaking it for an electric model.
Out on the lake when we had the chance to put the DF200A through its paces, in a single installation in a Beneteau Flyer 6 day cruiser and in twin mode on its larger Flyer 8.5 sibling, the outboards showed themselves to be lively performers with refinement. The smaller craft, with four aboard probably adding around 300kg or so to its kitted-out 1334kg displacement, rapidly hit 30 knots cruising speed at 5000rpm, peaking at 40 knots full throttle at 6100rpm.
Acceleration with the DF200A, we were told by the boat’s demonstrator, was as brisk as in the Flyer 6.5 that the V6 provides, although top speed with either outboard would have been fractionally more – around 41–42 knots.
Much more marked was the difference in fuel consumption. Running flat out we were burning 72 litres per hour, halving to 36 litres at 5000rpm. By 4000rpm that figure had fallen away to 21 litres. These figures show a significant improvement over the V6 at 200hp, which, we were told, consumed 10 litres more at top speed in the same boat model. Suzuki’s own factory testing, undoubtedly far more extensive than our own on this one occasion, indicates a 19 per cent improvement in the amount of fuel used at cruising speeds.
For the larger and heavier twin-outboard Flyer 8.5 (weighing in at 2730kg with engines, so just over twice the weight of the Flyer 6), performance and fuel consumption figures per engine were similar: 71.3 litres at 6100rpm and 40 knots; 32.1 litres at 5000rpm and 31.7 knots; 18.1 litres at 4000rpm and 22.4 knots; and below the plane 11.1 litres at 3000rpm and 11.4 knots.
In our DF200A trial on the two boats the performance figures were obtained using Suzuki’s new three-colour (white and red on black) 4″ LCD multifunction gauge, which is clear and easy to read, or would have been if visibility had not been marred by fogged lenses. But these were prototypes. When the gauge becomes available with the new outboard we can expect that problem to have been eliminated by the time it goes onto the market.
As for boat and engine noise readings, which we obtained using a handheld decibel meter, these confirmed first impressions that the new outboard is easy to live with. At 30 knots cruising speed and 5000rpm we recorded a comparatively civilised 83.84dBA.
A deluxe version of the new DF200A, designated the DF200AP, will be released in spring 2015. As well as the aforementioned multifunction gauge, this will have keyless ignition, developed from the system that’s been used on Suzuki cars for several years. For users it provides the convenience of not having to fumble around in pockets to find a key, but more importantly it offers increased security. The user just needs to be within 1 metre of the engine in order to start it. If he or she happens to move outside of that range, the outboard will continue to run – so it’s no substitute in that regard for the lanyard to kill the engine if the user happens to fall overboard. But should the boat be hijacked while the engine’s still running and the robber is able to make his getaway, he’ll never be able to restart the engine because the key fob is an integral component of the electronic programming of the engine. To do so he would not only have to procure a new electronic key fob, but also reprogram the engine.
It’s clear from what we’ve seen so far that Suzuki are determined to give Yamaha a run for their money across every power band in the market, and the new four-cylinder DF200A and the keyless DF200AP are the latest part of that strategy. Don’t be surprised if we see more powerful variants of these outboards making more use of the 2.8-litre block, which appears to have capacity to spare. Unsurprisingly, Suzuki engineers are coy about future product development, but no one’s denying anything either.
So, could new-generation, light and nimble, large-displacement, four-cylinder outboards consign the existing V6 and inline 6 flagship outboards to history? The answer is probably not for a while yet. The new units show a lot of promise when it comes to light and quick 6m-plus powerboats and RIBs, and are likely to be attractive prospects for repowering, but heavier outboards suit heavier boats and there are plenty of those still being built for recreational, fishing and workboat applications.
Europe-wide, Suzuki now claim a 20 per cent share of the outboard market, making them second only to Yamaha. On paper and on the water there’s little separating the DF2000A and Yamaha’s F200. In the end, it will come down to customer preference, with sales likely to be determined by customer service and price as much as technical differences. In practice, Suzuki tend to play the good-value-for-money card by coming in with lower prices than their main rival. Prices for the new DF200A/AP have not yet been announced, but they can be expected to be competitive …
Suzuki DF200A specifications
- Engine type: DOHC 16-valve
- Cylinders: 4 inline
- Piston displacement: 2867cm³
- Maximum output: 200ps @ 5800rpm
- Full-throttle operating range: 5500–6100 rpm
- Fuel delivery system: Multi-point sequential electronic fuel injection
- Ignition system: Fully transistorised
- Starting system: Electric
- Outboard weight: 226–231 kg*
- Recommended transom height (mm): L:508; X:635
- Engine mounting: Shear mount
- Gear ratio: 2.50:1
- Gear shift: F-N-R
- Steering: Remote
- Trim method: Power trim and tilt
- Exhaust: Through-prop hub
- Propeller selection (pitch – all props are 3-bladed): 3×16×17–27; 3×16×18.5–24.5 (C/R)
* Dry weight excluding propeller, depending on transmission leg length chosen