Irizar’s low-height i4 integral fulfils a variety of applications. It ticks boxes for a DDA-compliant interurban bus, a school coach, and a vehicle for short- to medium-distance day hires. Tim Deakin has driven an i4 in the Cheltenham-based Swanbrook fleet
The basic, high-capacity end of the coach market has become congested in recent years as manufacturers wake up to the need for a cost-effective and versatile offering which fulfils a variety of roles.
These coaches will never be suited for work as long-distance tourers, but when given the more mundane tasks they have been designed for, they often prove to be well-suited and economical. Among such current offerings is Irizar’s integral i4, in many ways a scaled-down version of the Spanish manufacturer’s top-end i6.
Several i4s are used as interurban coaches, and among them is an example supplied earlier this year by Worksop-based importer Irizar UK to Swanbrook of Cheltenham. It works seven days per week on Swanbrook’s scheduled service between its home city and Oxford, and was kindly made available by MD Keith Thomas.
The i4 is a comparatively low-height coach at 3.3m, but it retains much of the Irizar family look. The front door is a plug type, as is the wide centre exit, and within the centre door’s steps is where the Masats wheelchair lift sits, part of the DDA compliance package specified by Swanbrook.
Other elements of the DDA compliance items are a Hanover destination blind system, which includes side and rear repeaters, and high-visibility handrails.
All are installed on the production line in Ormaiztegui, and buyers need only tick a box on the order form.
The DDA package adds 15,000 to the purchase price, but is a must for operators planning to use an i4 on registered service work.
Below-floor luggage storage is reasonable, although the centre door and lift mechanism naturally intrude on this.
A spare wheel is provided, stored in the under-floor luggage area, although some operators would undoubtedly remove it. Luggage bay doors on the coach are manually operated and top-hinged. Also within the luggage lockers are relays and fuses, sited so as not to attract moisture and dirt.
Heavily-tinted bonded glazing is fitted, and combined with Irizar’s smooth panelling it creates a sleek look.
Fuel is added at the front nearside, and unusually the flap is released by a handle inside the coach, car-style. Irizar UK Sales Director Ian Hall says that the manufacturer also offers optional dual filling points on the i4, with one located on each side.
The 9.2-litre DAF PR265 engine is coupled to a 12-speed ZF AS-Tronic automated manual gearbox, although ZF’s six-speed EcoLife automatic is also available as an extra-cost option. On this Euro 5 coach space in the engine bay is reasonable, with it and the exhaust area having been designed with Euro 6 in mind.
Ian adds that the complete drivetrain is removable as one unit, and like the rest of the coach’s mechanical parts it is common with the i6 â€“ to the extent that it would be possible to swap mechanical units from one coach to another. Alcoa alloy wheels are standard.
Access to the i4 is good, helped by its low height and interurban service work being part of the design brief.
The entrance door is accessed by a step which is 36cm above the road surface, reducing to 27cm when the kneeling function is engaged. This works very quickly, and also returns to running height rapidly, certainly a lot faster than many of those on other PCVs.
Two further steps lead to the platform and one more to the sunken gangway. Surprisingly a courier seat is fitted, which slightly restricts entrance width; it would appear to be unnecessary in the Swanbrook application.
The platform is easily negotiated, helped by the lack of a cab door intruding into the space available. A ticket machine mounting point is provided.
As part of the DDA package, numerous yellow handrails are also present, along with highly-visible front and side destination screens and a rear numeral repeater. Although the i4’s windscreen is curved, the Hanover display is well-positioned and easily seen, but it does intrude into passengers’ views from the front.
Completing the coach’s accessible credentials is its wheelchair lift. This is a Masats unit rated at 300kg which retracts into the bottom step at the centre door when not in use, and as a result this door â€“ which also functions as an emergency exit â€“ is very wide, at over a metre.
The lift is fully automatic and requires no more input from the driver than to press the two buttons on its wanderlead-mounted control unit.
Pressing both buttons at once extends or retracts the lift from its storage area, and the two side guards also raise or lower as part of this process; they require no manual intervention.
Operation is quick, and the lift has an extendable ‘ledge’ which enables the wheelchair to access the aisle. The issue of a sunken gangway is taken care of by a removable section of floor immediately opposite the door, requiring the two pairs of tracked seats mounted on it to be removed before the piece of floor is unbolted from beneath.
As a result, and with the coach accommodating just one wheelchair, Swanbrook asks such users to book ahead to ensure the i4 is correctly configured for the day they wish to travel.
Straps for securement have been provided and are stored in the luggage lockers.
Seats are Irizar’s own, and there are 59 of them.
A high capacity while also including DDA compliance was key to Swanbrook’s decision to go for the i4, says Keith Thomas; the Cheltenham to Oxford service was previously operated with a 49-seat coach, which led to duplication sometimes being required for just a handful of passengers.
The seats are comparatively basic, reflecting the i4’s application, but recline and have folding armrests. Three-point belts are fitted and a deep red fabric has been specified, matching the curtains also present.
Service units above each seat pair include reading lights, stop request and ventilation.
Simple luggage racks are installed, with saloon lighting an integral component. The lights have two settings, with one giving a much-reduced degree of illumination.
Heating and air-conditioning is to luxury coach standards and comes from a Hispacold unit mounted on the roof above the front axle.
Heating is supplemented by perimeter radiators â€“ including a Spheros pre-heater â€“ and climate control means that the driver need do nothing more than set the desired internal temperature. A Bosch CD player adds to the passenger experience.
Ride quality of the i4 is very good, although as ever even the best suspensions are unable to completely isolate passengers from every pothole. The cabin is quiet, although the wheelchair lift contributed some rattling; both doors seal very tightly, with no wind noise detectable from either.
The driver benefits from an Isringhausen seat with a full range of adjustment.
The scope of its rearward travel is particularly impressive, meaning even the largest driver will be able to make themselves comfortable. The DAF steering wheel adjusts via a column-mounted toggle switch.
Storage is good, with a large bin to the driver’s right including provision for a two-litre bottle.
A further tray for smaller items is below the window, adjacent to the handbrake; the latter’s location to the driver’s right simplifies entry to the cab, also helped by gear selection being dash-mounted.
Switches are sited to the driver’s right except for a small number of infrequently-used examples. All are marked pictorially.
Gauges, with the exception of the customary speedometer, rev counter and coolant temperature and fuel level indicators, are presented via an LED screen and scrolled through by a steering wheel-mounted button. Besides air pressure and AdBlue level, the display can also show tyre pressures and temperatures, oil pressure and temperature, fuel economy and the battery’s state of charge.
A manual, two-piece sunblind is fitted and the pedals are easily reached. An electrically-lowered and heated signalling window is provided, although its frame can make observation awkward at some junctions.
Mirrors are of the gullwing type, but are mounted much closer to the windscreen than on some other coaches, reducing the likelihood of accidental damage.
They give a good view, and the largest mirror on each arm is adjusted electrically.
The i4 has DAF’s 9.2-litre PR engine rated at 360bhp, and driving through a ZF AS-Tronic automated gearbox it gives a smooth and quiet ride.
The transmission, in particular, is worlds away from earlier versions of AS-Tronic: it is smooth changing and quick-thinking. It selects third gear to pull away and block shifts as far as ninth before utilising each of the three highest ratios.
Performance is more than adequate and, again unlike the earlier AS-Tronic, clutch control is almost as good as in a manual. Reversing in Swanbrook’s yard was easily accomplished without any of the lurching which would have occurred on earlier versions, and shifts are made rapidly.
The i4 is geared very highly, and doesn’t select 12th until around 60mph. At the limited speed, the engine is turning at just under 1,200rpm, which is more than enough for a lightly-laden coach on flat ground but may prove slightly optimistic when running with a full load on undulating motorway, although it is within the engine’s very wide torque band.
Manually dropping a ratio is easy, however, and the tall gearing will undoubtedly contribute to good fuel economy in most situations. At 55mph it also proved possible to manually shift into top gear, at which point engine speed is around the 1,000rpm mark; the driveline gave no complaints.
One of the most impressive of the i4’s many positives is its road holding.
Keith Thomas devised a route including more A-road running than motorway to reflect the coach’s day-to-day duties, and when pushed into corners it displayed no body roll and gave the driver full confidence in its abilities.
Ian Hall puts this down to independent front suspension, which undoubtedly helps. The coach’s low centre of gravity also contributes to the positive experience, as does excellent and very precise steering.
This coach has been bought for a specific purpose, and that keeps it busy seven days per week. An older accessible coach is held in reserve, which has allowed Swanbrook to use the i4 on a handful of private hires since it arrived. It has performed well in both applications, reports Keith.
As an interurban coach, there is little to fault on the i4. It offers passengers many things that, while common on high-end tourers, are either difficult or impossible to incorporate into a bus, and Keith is happy with his purchase, saying he would buy another without hesitation.
â€œWe were looking at a pair originally, but took just one to see how it worked out,â€ he says. â€œWe’d have another, without a shadow of a doubt. Irizar UK has impressed us and passenger response has been excellent.
â€œWe need a bit of everything out of the coach, and that’s what we’ve got. We wanted a no-frills, DDA-compliant vehicle, and looked at what else was available on the market. The combination of a DAF/ZF driveline, high capacity and the right price is what did it for the i4.â€
It’s difficult to argue with Keith’s assessment. Irizar aims the i4 squarely at the high-capacity, no-frills end of the market, and prices it accordingly. One of its attractions is the optional factory-fitted DDA compliance package, which renders the coach suitable for stage work in the long term.
It shares many features with the range-topping i6, however, and is a versatile and willing coach that is equally at home on scheduled interurban work as it is eating up motorway miles.