ROAD TEST: i6S Efficient Integral 12.6 two-axle

When a coach builder lays claim to 13% fuel savings, it’s time to investigate. Irizar’s i6S Efficient, fresh from a roadshow tour of the UK, comes under the Bus & Coach Buyer spotlight
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Fresh and frugal


The fanfare with which Irizar announced its i6S Efficient across Europe came with images of a coach which looked remarkably familiar.

Game-changers are usually obvious to the naked eye but, if you know anything about Irizar, you’ll know that’s not the way they do things. It’s a company with style in its DNA, going back to the Century which wowed operators in the 1990s and then the PB which image-conscious brands such as National Express bought in number.

Since the PB days, Irizar has smoothed a few bumps and sculpted a few curves but its coaches still bear the same styling cues. Anyone expecting a departure from Kardashian curves has got Irizar wrong. Yet, I discover, the i6S Efficient is much more radically changed than just a superficial makeover.

I’m going to repeat the company’s claims for the i6S Efficient because they are important; 13% reductions in fuel consumption, 950kg lighter and 30% reduction in aerodynamic drag. These are big claims, and you can’t make them without having made big changes. So we thought we’d go to Worksop, hop aboard, and find out not only what those changes are, but how they change the i6S.

There has been much focus on the installation of camera mirrors on this coach, and indeed Neoplan’s Tourliner. They are just a visible element of a much greater effort to squeeze every mile out of every gallon of diesel, and those changes start with the shape of the vehicle. Park this alongside the previous model and they’re more obvious.

The new i6S Efficient – more rounded and aerodynamic

The previous i6S

The entire profile of the front of the i6S has changed, to become smoother with more curvature in the windscreen and a reshaped roof along aircraft principles to ease the passage of air around the bodywork. In fact, Irizar has shifted the entire body of this coach 10cm further forward over the wheelbase to achieve better balance.

The rear mouldings are new to reduce rear turbulence. The driver’s seat is moved forwards over a shorter dashboard to help the driver with the view of the road. And alongside these radical changes, Irizar can eke the best out of the already frugal MX11-300 408bhp engine and, on the test example, ZF’s EcoLife CoachLine automatic gearbox, heavily optimised to, itself, achieve 3% fuel savings.

Then there’s the saving of almost a tonne in weight by using high-tensile metals and composites to replace hefty elements of the structure, coupled with weight savings wherever they could be made, including in the interior. The engineers must have been reading about Colin Chapman…

As Irizar UK’s Sales Director, Julie Hartley, said on the morning we left the showroom forecourt with the road test vehicle – which had, by then, toured the UK up to Scotland on its roadshow – operators who prefer automated gearshifts may see even greater fuel savings from ZF TraXon in the driveline. One thing the road show did achieve was a real-world test of the claims. More about that later…


It would be foolish to describe the overall look of an i6S. But in addition to the remodelling of the iconic shape I have mentioned earlier, there are some changes.

The remodelling of the front can be gauged by taking a look at the ‘old’ i6S front of Heathside’s that we road tested. The roofline has been pulled back a little so the screen has more rake, and is also more profiled at the sides to achieve better aerodynamics. The iconic roof bump has also been reprofiled.

The rear mouldings have been completely redesigned to reduce turbulence drag at the back. There are subtle changes, such as the removal of the ‘eyebrows’ over the front marker lights. But the main changes are beneath the skin of the i6S Efficient, which has been light-weighted by a remarkable 950kg – almost a tonne.

This has been achieved with a root-and-branch examination of the structure of this integral vehicle, re-engineered for every weight saving possible. The coach uses more composites and high-tensile steels which offer the same strength for less weight. And then there are the ‘mirrors.’

You have only to watch the behaviour of hefty, long-reach mirrors to understand that they are bound up in the aerodynamics of a coach. No matter how well-made they are, at speed they flex and wobble as turbulence pulls them around. Replacing them with cameras and monitors makes a significant contribution to the reduction of drag.

Radical change always polarises opinion, so I may be in a minority when I say I think that the lack of more conventional mirrors enhances the appearance of the i6S Efficient. I have never been a fan of the ‘Grommit’s ears’ mirror stalks. Suffice to say that the cosmetic difference and the improved aerodynamics are far from being the only reason why I predict that camera mirrors will become standard within the next couple of years. More of which later.

The addition to this UK-spec test vehicle which makes the biggest difference to its appearance may well be the installation of a wheelchair lift, and the hefty door framework which sits just aft of the rear axle on the nearside. The installation itself is very smart and the lift works very well. In the test example, two seat pairs have to be removed to create the wheelchair space. Irizar is working on a tip-up-and-slide seat solution so the seats can stay within the coach.

One major change reveals itself when we reach the passenger doors. Both the continental door and the main passenger door are brand-new, and a radical change. Irizar’s Masats company has designed the electrical Swyncro door mechanism which does away with all the unsightly stays and steadies of pneumatic doors, replacing them with a single, if hefty-looking, mechanism which works differently.

Gone is the usual motion in which the door closes then lifts into its wedged position. Instead, the plug door just closes and latches. The latching is independent of the door closer. Julie Hartley demonstrated that it’s possible to manually push the door into place and, as it moves into place, the latches operate to lock it. It’s much tidier and declutters the passenger stairwells.

The lockers are big, though of course the toilet does fill a significant portion of the available space. Other tweaks include the position of the nearside fuel and AdBlue fillers, with plenty of separation and clear marking to reduce mistakes.

The i6S remains a very good looking coach from every angle.


The main passenger entrance is up three steps to the driver level then a further step to the aisle. As I have mentioned, the new Masats door tidies the entrance up.

On the right, the courier seat stows neatly with little intrusion, and there is a good stainless steel handrail to the left. There are new step lights. The dash immediately opposite the courier has a wired mic, speakers and air vent. The decency screens on both sides are new, with the front passengers’ table now formed from a soft, air-filled plastic which can take a knock.

The driver gets one of the best dashboards in the business. The driver seat has been moved forward slightly, so the view in all directions is excellent. The switchgear is in logically-arranged clusters, and the central LCD illuminated binnacle with tachometer, speedometer and the central selectable vehicle information is bright and free of obstruction, clearly visible through the steering wheel, which has the familiar (to i6S owners) multicontrols. There are twin, independent sunblinds.

The saloon is a bright and welcoming environment with ample lighting and ventilation. Overhead, the Hispacold air conditioning looks no different but, in fact, a new unit with ECO3 air purification as standard. On the roof, the number of condenser units has been reduced from five to three, reducing weight, but the output is the same.

At this point, I must explain that the i6+ seats you see in this test vehicle are not the seats it was destined to have. The i6S Efficient will have a special slim seat which not only reduces weight but also allows a full 57 seats on the 12.9-metre two-axle. Unfortunately, a supplier issue meant the use of the seats you see here; this affects the seat spacing, too, so the relative positions of the window pillars and overhead service units will be different when the correct seat is fitted.

That said, the intrusion of the B pillar combined with the wheelchair door frame in the passenger view is quite stark in nearside seat row three, and probably unavoidable no matter what the seat spacing. Without the wheelchair door frame, it would be more acceptable.

In addition, the Hanover destination screen – though it now curves to match the screen – does intrude into the forward vision. (The side destination boards are built into the panel, unlike some coaches we have tested). That’s just unavoidable on a PSVAR coach. With these caveats, the saloon is a very nice travelling environment.

On the road

Our Coach Stig is a veteran of Irizar products, so the i6S Efficient was familiar territory for him. Familiar, but also different.

The repositioning of the driver seat has given it more adjustment backward, so that even the longest-legged driver will be able to get comfortable. The dashboard is, of course, the same as the i6S.

The elephant in the room are the mirrors; not the first we have seen, but in many ways, perhaps the best so far. Camera units are installed on both sides at roughly the same position that mirrors would have been mounted, with an additional camera giving a wide-angle view at the front of the coach. The driver has a split-screen view in both monitors, the screens mounted on the nearside and offside A pillars. The lower third of the screen shows a wide-angle view, the upper, main part of the screen showing not only a more normal view, but incorporating markers showing the position of the rear of the coach, the axle position and a point six metres behind the coach.

From the start, the test driver could see the advantage of the system, as he negotiated the forecourt at Worksop. Making a very tight turn left, with a parked coach in front, he was able to manoeuvre the coach to within inches of the parked coach, as he had no mirror stalk to worry about. The same happened when we returned; he made a turn which would not have been possible with large mirror stalks in front.

The driveline is a familiar one, utilising DAF’s MX11 engine in 408bhp guise and ZF’s EcoLife CoachLine automatic gearbox. The combination gave good pick-up from the start and seamless gearchanges throughout the test drive; this is the EcoLife CoachLine released in spring this year, claiming a 3% fuel saving which, as we found out on the test drive, is accomplished not only with programming which selects the perfect gear for any incline but also disengages on the over-run – evidenced by the tachometer dropping on a downhill run on the motorway.

EcoLife is the main choice of most operators, Julie Hartley says, but of course the coach can also have the ZF TraXon automated gearbox, with the possibility that this will deliver even greater fuel savings. We’ll find out when an example comes.

Once we were out on the A roads, the ride quality and the performance of the driveline were clear. This has always been a very nice combination. The saloon is quiet throughout but in particular, the test driver remarked on total silence from the passenger door. The absence of lower glass in the door, by the way, is probably negated by the camera over the door.

The i6S Efficient has adjustable suspension, the settings found on the centre ninnacle. It can be made to ride a few centimetres higher on uneven roads, though this setting returns to the normal ride height at speeds over 30mph. There is of course a ferry lift mode.

“The steering isn’t too light, unlike some,” said the driver. “I’m getting good feedback from the steering wheel and the coach feels really planted, so on the straight sections of road, I don’t have to make any corrections. You just set the steering wheel and it does the rest.”

The road test encountered some brooding dark clouds which turned day to night. The Coach Stig was by then acclimatised to the camera mirrors: “They are definitely better than conventional mirrors in poor light.” This is a common comment, and we are told by drivers the mirrors are better still at night. The camera’s multiple lenses proved to be untouched by the rain; a jet of air is projected on to the lenses to keep them clear.

The road test was, then, uneventful, and that’s a massive plus point for any road test. The test driver – a coach operator – strongly suggested that the current way the mirror monitors are mounted is changed; they look a little ‘aftermarket’ mounted to the A pillar like this, and it was suggested the A pillar shrouds could be moulded to accept them, and deny any access to the wiring behind them.

But what you really want to know about is the fuel consumption. The onboard computer suggested that on our road test, we’d achieved 12.7mpg. Irizar, however, monitored fuel consumption throughout its lengthy roadshow with the vehicle, and says 12mpg was the lowest on any mixed run; on the A1 run to Weardale from Worksop, using the tank-to-tank method, it achieved 15mpg. That’s impressive, especially on a new coach.


The i6S Efficient won’t be around for very long. What you are looking at is really the new i6S, and the ‘Efficient’ moniker will soon be dropped.

So how does it fare as the replacement for an already successful coach? The answer has to be ‘very well indeed.’ It’s a lovely machine in almost every way, and if it delivers the promised 13% fuel saving for operators, with diesel prices ever rising, it has a very bright future ahead of it. It has built on its predecessor not only on economy, but a number of other revisions, such as the air con compressor bracket which has been redesigned, and access to the toilet fillers improved. The i6S is both revolution and evolution.

I am really looking forward to seeing the 13.2m tri-axle, and for one main reason. The first is that in PSVAR spec, it will stow the wheelchair lift over the rear axle, and that will avoid the doorframe clash with the B pillar, which does ‘do a number’ on the view from the window. I am sure the seat positioning elsewhere will improve when the new, slimmer seat is fitted in the production run, but like the intrusion of the front destination panel into the windscreen, it comes with the PSVAR territory.

Irizar can supply their model range with all of the wiring, the door and the bay for the wheelchair lift installed, so that you can upgrade to PSVAR at a later date. That’s certainly an option. My greatest concern is that, when the reality of accessibility on coaches is examined, or a new solution becomes available, the compromises this equipment creates will have been in vain. I hope I am wrong.

Irizar i6S Efficient, 12.9m, 55 seats (57 in production)
Retail £285,000
Length 12.9m
Width 2.55m
Engine DAF Paccar MX11-300
Power 408bhp
Gearbox ZF EcoLife CoachLine with intarder
Axles – front ZF RL76EC independent
Axles – rear ZF AV132
Suspension/brakes WABCO
Steering ZF
Fuel capacity 480 litres
AdBlue 50 litres
Wheelchair lift Masats K7 semi-automatic
Destination equipment


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