Product Test and Review of the 2009 Suzuki DF90 Outboard
As 2008 draws to a close, one of the most talked about topics for the year has without doubt been the price of fuel and the knock on effect this has throughout virtually every aspect of all our lives. At the time of writing, prices were starting to dip a little. But it's still staggeringly and needlessly expensive. Boat angling in particular has suffered badly from the upward price spiral because boats can hardly be described as a fuel efficient mode of transportation. Having water to push their way forward through which is far denser than air means they can never really be anything else. As a consequence, for many charter boat skippers, fixing the cost of trips for anything more than a couple of weeks ahead has been something of an impossibility. Even getting to venues, particularly for inland based sea anglers has started to become cost prohibitive. But for small boat anglers, the real day to day running costs only really hit home when the boat has been slipped from its trailer and starts heading out to sea. Outboard engines quite literally drink fuel. So any manufacturer that can either reverse, or even simply help stabilize that situation through fuel efficiencies, is going to make potential customers literally sit up and take note, which is what Suzuki feel they are about to do with their new DF range of outboard engines.
Suzuki have been a sizeable player on the outboard scene for as far back as I can remember. Now rumour has it, they feel its time to challenge for, and ultimately ascend up into the number one engine producers slot. I am told the avowed aim of the company is to have the biggest outboard market share within the next three years. Quite a target to set yourself. But biggest doesn't automatically go hand in glove with best. At a one to one level with outboard users, the company will still have to impress those customers who can make the statistics become reality, and for that the product must not only be right, but must be seen to be right. Fuel efficiencies are a major step in the right direction. But equally, word of mouth promoted by long term durability and observed reliability are also vitally important. So when I was invited to play with and comment on the new Suzuki DF90, I also made a point of doing my homework in some of the other important peripheral areas too. Its one thing trying a perfect brand new engine and commenting on its performance on the day. It's quite another being given the responsibility of potentially persuading others to part with their hard earned cash if this turns out to be unjustified as a longer term investment.
I'm lucky in that one of my regular fishing buddies, Charlie Pitchers, has been a Suzuki user for the past three years. On top of that, I've fished from a number of other boats where Suzuki have been providing the power. Wirrall angler Mickey Duff who I've done a couple of BFM features with is one of them. And all have been completely satisfied with the reliability and performance of their engines. But there is still more to it even than that. I like to go much further back in time if I can, looking over the oldest models I can find out there to check out how they have stood up to the test of time both physically and mechanically. Wear and tear caused through mis-use are no criteria on which to judge any outboard. But durability of for example the paint job generally, is. Sea water is a particularly aggressive medium for most things metal, hence the need for outboards to have sacrificial anodes to protect their metal casing. Even so, paint can still be lost, particularly along the edges of seams. Blistering of the legs, which across the board was a problem maybe 30 years ago, is now quite a rare sight. But flaking around the edges can still occur. Happily, none of the Suzuki's I managed to look at fell into that category. And mechanically there have been no complaints either. So in that respect it seems the company have a good foundation upon which to start expanding their ambitions.
Now back to the particular job at hand. Visually, this is a very impressive piece of kit. Its black livery complimented by the silver and red decals make it especially pleasing to the eye. Equally impressive from a visual perspective is its physical size. In the DF70, 80 and 90, Suzuki's designers and engineers reckon they have created the most physically compact four stroke outboard engine on a like for like horse power comparison on the market. But as they say, it isn't the size of your piece of kit so much as what you can do with it, and for once it seems smaller might actually be better, if as in this case it means lighter, and in turn, lighter equates to improved boat handling through balance, and perhaps a little bit of added fuel efficiency. However, its the lean burn control system that delivers the real fuel efficiencies for the DF range. Designed to run on a thinner fuel mixture through the use of a lean air to fuel ratio, this should provide fuel savings that are clear for everyone to see. To quote the blurb in the DF90's product information sheet, this is achieved through a reduction in fuel pumping loss. And in order to balance these efficiencies with clean emissions legislation, the system automatically sets up the air to fuel ratio to take advantage of the reaction characteristics of exhaust emissions.
Okay, so this range of outboard engines supposedly performs all sorts of new and magical tricks. But to the average man in the boat, these probably mean very little, unless of course they relate to something he can readily measure like vastly increased sailing distances on a tank full of fuel. Suzuki reckon that could be as much as 22% more than previous like for like Suzuki models. But what we as consumers can't do at this stage is make meaningful comparisons ourselves, because four stroke engines take many running hours to loosen up in terms of power output and running economy which would rule out any attempt at comparison until such time as the new DF models were suitably run in. Another fuel efficiency calculation problem is that with Suzuki's main competitors also working on updating their fuel efficiencies, the DF90's improvement does not equate to 22% more than the companies rivals. This said, I am impartially informed that even taking account of competitor efficiency improvements, the Suzuki DF range is still streets ahead of the opposition. Not so much at the high speed running end of the fuel burn curve where it looks to be about as thirsty as the rest. But in the middle of the curve where a boat is running at say a half to two thirds throttle, which as anglers know only to well due to sea conditions is unfortunately most of the time, there appear to be very good comparative fuel savings to be made.
One of the projects I have been working on recently is both the pre and post production sea trials of the new Warrior 170 Fisherman. The plan was to do these trials with a the Suzuki DF90, which for a number of reasons I will come to later, is the favoured package partner for this particular boat. But unfortunately, or from my point of view here perhaps fortunately, the DF range was so new that when it came time for the 170's début handling trials, the engine ear marked for it was still on a ship somewhere between the UK and Japan. So we had little other option than to temporarily clamp one of Suzuki's main rivals to the transom instead, the upshot being that I now have some personally generated like for like performance figures of two brand new first time on the water competitor engines used on the same boat as a yard stick for comparison. Granted, some minor changes have been made to the boat between the engines being changed over. That said, these were so minimal on the Leisure version of the boat as to make little or no actual difference in terms of overall speed and acceleration.
Claims by Suzuki of the DF90 being the lightest 90 hp 4-stroke engine currently on the market however could make a difference in a number of quite important ways. Eleven kilo's lighter than a comparable Honda, and 13 kg lighter than a comparable Yamaha may not sound a great deal, but depending on the overall length of a boat, in the world of fulcrum physics, that can equate to a hell of a lot in performance terms. Increased weight at the back of a boat, unless it is counter balanced in some other way either by physically placing additional counter weight up front, which is less fuel efficient due to the extra load the engine then has to push, or by adjusting it out with the trim button, can not only make a boat boat less comfortable, but can also make it's handling unsafe, particularly at speed in choppy conditions. And when a boat is back heavy, there is only so much you can do with the trim button before there isn't any room for adjustment left. So in that sense less weight on the back at its furthest extremity can do nothing other than good in terms of handling, with any resulting minor fuel efficiencies resulting from that weight drop coming almost as a mini welcome bonus. At least if the back end were to be a little light as a result, you can trim this out by tilting the prop up a little higher in the water, something you will not necessarily be able to adjust out if the engine, or more to the point, the general positioning of onboard weight in the form of batteries, anchors and fuel, is too heavily displaced towards the back.
To an extent, this was one of the handling issues we found with the Warrior 170 on its début run out. The plan had been to design a couple of couple of extra degrees of tilt into the transom to negate the need for a transom wedge. This however proved not to be enough, which while it did not adversely affect the handling of the boat, did mean there was no scope for adjustment in changing sea conditions. Obviously, the use of a transom wedge at the time of engine fitting will, as it does on many boats already, bring that flexibility back, which was the case when the first production Warrior 170 was taken down to Weymouth for a joint press launch with the Suzuki DF90. And there it felt like a completely different boat. The object of this particular article obviously is not to re-test the Warrior 170. But its performance on the day with the DF90 fitted was like a breath of fresh air compared to the début run, and in no way can all be attributed to the transom wedge. The whole balance and ride of the boat felt better. It was considerably faster too. In terms of sheer acceleration it was quite literally breath taking. On a fishing boat, I have never felt anything like it before. Yes, the design of the boats hull was facilitating this. But that was also the case earlier with the competitor engine, which while that was most certainly nippy too, did not feel as good as this. At the top end the DF90 was also marginally faster taking the boat up to a touch over 42 mph compared to 40 mph on the début run out, though that could be attributable to other factors such as wind or tide as it's difficult to exactly repeat any trail at sea.
From a day to day angling point of view, the rest of the performance info on the handout sheets for the DF range is probably of little or no real interest. That said, I did spend a quite a bit of time looking in detail at some of the facts and figures quoted, and comparing them to specifications for other 90hp 4-strokes available on the Internet. And from what I could see, the DF90 isn't actually the lightest comparable engine on the market. At 143 Kg compared to the Suzuki's 155 Kg, that honour falls to the Tomatsu, though the Suzuki does have 235 cc of additional engine capacity. Even so, I know which one of the two I would feel happier with. As for the other features such as the anti-corrosion layering of the paint job, and the alternator output which can keep essential navigational instruments functioning in the case of a battery failure, there wasn't that much to choose between all the big manufacturing names, though I am informed that the DF range can keep the instruments running even at low revs in bad sea conditions which previously has not always been the case. However, where the Suzuki does excel, on paper at least, is in its gear ratio, which at 2.59:1 is more than 10% higher than its nearest rival. In real terms this means that if the engine under load can achieve comparable revs, it is going to push a boat along considerably faster than competitor 90's, which we know from the début trials at Knott End, it did achieve by a fraction at Weymouth. But as I said earlier, we were not unfortunately matching like for like wind and tide conditions.
Would I put fit one of the Suzuki DF range to the transom of my boat. Un-questionably, yes. For me it ticks all the boxes, in particular those relating to power delivery, responsiveness and pace. Quietness is something else I also picked up on, which is another reason why when you look at the GPS speed over ground facility, you can be surprised by how fast you are actually going compared to what you might think. I'm not sure about the Easy Start System which, when you turn the key, automatically keeps the engine turning over until it starts. That's something I think I could probably live without. Otherwise, an extremely impressive piece of kit that will almost certainly help elevate Suzuki's standing in the competitive world of outboard engine manufacturing.