Mellor has reset the bar for minibuses with the 27-seat Strata Ultra on Sprinter underframe. We drive it
Mellor delivered a surprise at Euro Bus Expo with two extended versions of its Mercedes-Benz Sprinter-based Strata low-floor minibus, the 8.11m Plus and the 8.78m Ultra.
Both build on the initial 7.76m Strata. 110 of those have been delivered and the first Plus and Ultra examples for customers are expected to enter service in May.
The newcomers are likely to further expand the Strata range’s appeal to operators engaged in stage carriage work. The Ultra seats 27 passengers and it carries three standees.
To achieve that capacity, Mellor increased the rear axle’s weight tolerance to deliver a GVW of 6,000kg. It is in the process of receiving a Letter of No Objection from the chassis OEM, which will give the work Mercedes-Benz’s blessing.
“The response to the Strata has been fantastic, which encouraged us to extend the range. We now have a nice line-up of small buses that are attractive to passengers and which give excellent fuel economy,” says MD John Randerson.
The first named buyer of a Strata Ultra is Stringers Coaches of Pontefract. The prototype that garnered such attention at Euro Bus Expo will soon move to Millbrook Proving Ground for durability testing. Before that, it was made available for a routeone Test Drive.
Build
Both the Ultra and the Plus are simple extensions of the existing Strata and so they stay at 2.30m wide and 2.76m high. The wheelbase grows by 10cm and additional length is at the rear. The exhaust arrangement is modified to suit the low-floor bodywork. It vents immediately behind the offside front wheel. The fuel filler is moved to the rear, again on the offside; a cut-off for the auxiliary heater is adjacent.
During development of the Plus and the Ultra, Mellor removed weight from components that are shared across the Strata range. There is a slight fuel penalty with the extended variants’ additional mass, but the manufacturer still expects a return of around 18mpg on urban work.
Steel suspension is fitted all round, but airbags can be fitted at the rear should the buyer require. As a result, no kneeling facility is possible, but the step height of the prototype is 27cm and that will reduce to below 25cm once productionised.
A Hanover front, side and rear numeral repeater destination display package is fitted to the prototype. Single-colour LEDs are part of the purchase price; as tested, they display in white.
Both the Plus and the Ultra variants will exclusively be built on the new Sprinter. Although much has changed technology-wise, its driveline remains the same as in the previous model.
Mellor’s standard specification utilises the four-cylinder, 2.1-litre OM 651 engine rated at 163bhp and 360Nm of torque coupled to a 7G-Tronic seven-speed automatic gearbox.
Passenger access
A 950mm single-piece sliding door is fitted to all Strata models. Within the opening is a manual ramp as standard, although a powered alternative is available.
A wheelchair bay is on the offside. Within it are three tip-up seats; four nearby fixed positions give a total of seven that can be reached without encountering a step. A second wheelchair or buggy bay can optionally be positioned on the nearside.
Two shallow steps lead passengers to the high-floor area. A vertical stanchion is affixed to every offside row; each aisle position has a grab handle. An emergency door is at the offside rear, and thus the back row is made up of four seats with space adjacent to the exit.
Passenger comfort
This is where the Strata Ultra prototype excels. It delivers, as a minimum, an environment that is comparable to that of a premium full-size bus. While Mellor added a host of options to suit the minibus’ visit to Euro Bus Expo, they give an idea of what is achievable.
All 24 forward-facing seats are Kiel’s high-backed Ligero model. In the prototype they are trimmed in grey synthetic leather complemented by blue moquette. When combined with a ceiling and walls that are finished in light tones and metallic grey handrails, the effect is impressive.
Additionally, Mellor has fitted wood-effect flooring and USB points for every passenger. In the low-floor section they are within the sidewalls. At the rear, they are in the middle of each seat pair.
The latter is an example of attention to detail. The sockets are easily reached at an approximately 45-degree angle.
Seven wireless bell pushes are included, along with a further one within the wheelchair bay that differentiates itself with a different chime.
Leg room is good enough in the rear area, although tall passengers’ knees may touch the back of the seat in front. The view throughout the Strata Ultra is excellent, helped by deep glazing and narrow pillars. Additionally, a large rear window admits much natural light.
Twin LED strips provide saloon illumination and they deliver either bright white or muted blue light.
Four sliding window vents are fitted, while heat comes from either an Eberspächer or a Webasto diesel-fired air heater rated at 5kW. In both cases it is at roof height above the wheelchair bay and there are four outlets split between the front and the rear.
The prototype Ultra is fitted with an audio-visual next stop announcement system as a further example of what is possible in the Strata. A display unit is fitted centrally above the low-floor area.
Driver comfort
This was the first opportunity for routeone to drive the new Sprinter. The chassis OEM aspects of the cab are completely different to the previous model. Welcome will be the removal of the large selector lever for the 7G-Tronic. Gears are now chosen via the right-hand stalk.
Mellor fits a small cab door, held shut magnetically. The opening is narrow, and larger drivers may find passing through it awkward. Above are two money trays and a ticket machine mounting plate. Mellor has already developed an anti-assault screen for the Strata, while the Ultra as tested has a large luggage pen ahead of the door.
Storage space to the left of the hydraulically-suspended seat is good, but there is none behind it or to the right. Room around the pedals is reasonable, although the driveline tunnel intrudes slightly, as is usually the case on front-engined vehicles.
A powered one-piece blind and a small signalling window are both fitted. The former, like other body functions, is controlled from Mellor’s switch bank that also includes warning lights for items such as the emergency door.
Although non-standard, the prototype Ultra has Mercedes-Benz’s MBUX infotainment system. It consists of a large touch-screen display at the centre of the dash that delivers a huge amount of information.
As an example of that, it can produce graphs detailing the engine’s power and torque outputs at any time. It also includes an electronic owner’s manual to complement more mundane functions such as satellite navigation and radio controls.
Mirrors are adjusted electrically, while the cab heater controls are simple. They utilise a dial for each of temperature and fan speed, and buttons to direct the airflow to the driver’s feet or the windscreen.
Visibility from the cab is largely good, and the driver almost has the feeling of sitting in a fish tank, such is the expanse of glass around him or her. The base of the A-pillars is substantial, however, and the nearside mirror is very slightly obscured as a result.
Performance
The OM 651 is modestly-sized for use at 6,000kg GVW, but it still delivers a power-to-weight ratio that would be the envy of a larger bus. It’s well harnessed by the 7G-Tronic, which without exception shifts smoothly. Mellor has not revealed the Ultra’s UVW, but it does feel slightly heavier than Sprinter van conversions. As a result, a good prod of the accelerator is sometimes required, but when the throttle is fully opened the minibus accelerates rapidly, even when heading uphill out of Rochdale.
Noise levels are muted and the small steering wheel gives a car-like driving experience. In fact, the new Sprinter shares much with the Mercedes-Benz car range; it has keyless ignition and dual paddles behind the steering wheel to force up- and down-shifts.
All Stratas are limited to 62mph, and while it was not possible to put the Ultra through its paces at that speed, past experience with Sprinters suggests that it will be easily capable of high-speed work.
Conversely, it is equally at home in the urban environment. At 8.78m long the Ultra is no baby, but it is highly manoeuvrable nonetheless.
In particular, leaving Mellor’s premises proved its abilities; it easily achieved what looked to be a very tricky turn without coming close to the kerb.
Verdict
New vehicle launches by Mellor have been abundant of late, but none can have opened it up to such potential volumes as the Strata Ultra.
At 30 passengers within a roomy and welcoming saloon, while delivering a promised fuel efficiency that is beyond any rear-engined bus, it has the potential to significantly alter the economics of low to mid-demand services.
Mellor is confident in the product. Its three-year body warranty complements coverage of the same duration provided by Mercedes-Benz on the chassis, and John says that the vehicle has a ten-year design life. The new Sprinter is a pleasure to drive, and as shown on the prototype Ultra, the Strata can deliver almost anything that a larger bus can from a passenger’s perspective.
In particular, items such as high-specification seats, next stop announcements, charging points and wood-effect flooring certainly put it into the premium segment that is becoming popular with many operators.
Retail price of the Strata Ultra will start at below £110,000. Couple that to what is promised will be low fuel consumption, a strong warranty, excellent parts availability for the base vehicle and a fine passenger environment, and Mellor’s recently-enhanced production capacity may be required sooner rather than later.
Facts and figures
Retail price: From below £110,000
Engine: 2.1-litre, four-cylinder Mercedes-Benz OM 651
Power: 120kW (163bhp) @3,800rpm
Torque: 360Nm @1,400-2,400rpm
Emissions: Euro 6 using EGR and SCR
Tyres: 205/75 R16
Fuel economy: 18mpg (expected figure)
Length: 8.78m
Height: 2.76m
Width: 2.30m
Wheelbase: 5.10m
GVW: 6,000kg
UVW: TBC
