Power plus for Merc 6x
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The Mercedes 2527 for tipper and mixer applications makes its debut at TipCon. Its power is 23% up on its predecessor and it turned in a good performance on a short test.
• Mercedes launched the 2527 6x4 chassis earlier this year and this week it makes its UK show debut at TipCon. The chassis is designed for mixer or tipper operation; we have been able to try out the tipper.
The big difference from the 2422 it replaces is in the engine bay: at last Mercedes has produced a 6x4 chassis with competitive power output. In place of the 2422's throbby 11-litre vee-six is one of the new LEV Eum-1 engines-11 litres are reduced to 9.57 but power rises by 23% to 200kW (268hp) at 2,100rpm. Torque is also up, to 1,090Nm (8041bft) at 1,200rpm.
Mercedes reserves its EN gearboxes for tractive units with more than 224kW (300hp), so the 2527 gets the G155-9/15 eightspeed synchromesh range-change box with crawler. The PT-0 (standard on mixer chassis) is a directdrive unit driven off the back of the engine; other PT-Os are available.
In other respects the chassis is little changed from its predecessor. The first two numbers in Mercedes model numbering usually indicate gross vehicle weight, while the second two indicate power in horsepower, so 2527 suggests a 25-tonne GVW. Don't be fooled—the outer axle spread has been stretched to 5.2m for operation at 26 tonnes Back bogie The front axle, suspended on parabolic leaf springs, is rated at 7.5 tonnes with a back bogie designed to handle 20 tonnes (UK plated weights reduce that to 19 tonnes in operation). An anti-roll bar is fitted to the front axle but not the rear two spring bogie; cross and inter-axle diff locks are standard at the rear.
It's a bit of a hike up into the cab: Mercedes opts for two steps where other manufacturers use three. Although the bottom step is well clear of the ground, it is sensibly designed to fold under impact.
Air-suspended seats are an option in the Merc but we found the standard issue items comfortable enough. The standard day cab is suspended by rubber dampers on the pivot bearings at the front and coil springs and dampers at the rear. Opting for the M-type short sleeper cab adds 180kg to the kerbweight but should offer a better ride. The front of the cab gets U springs and shock absorbers while the rear gets the transverse leaf springs and dampers found on all Mercedes heavy cabs.
The 2527's good cross-cab access might not be at the top of many tipper buyers' shopping list—but it does help make the cab easy to clean—as does the grey plastic floor covering.
The dashboard is standard Mere issue except for the lack of an EPS indicator above the instruments. The big steering wheel is adjustable for height and reach, so it's quite easy to find a comfortable driving position. Visibility is good too, with a kerb mirror and heated door mirrors as standard.
Turn the key and instead of the chug-chugging of the 2422's natu rally aspirated vee-six, you hear the smoother rumble from Mercedes' smallest charge-cooled LEV engine. Like the other veesix LEV engines it revs smoothly and freely, which could encourage the leaden footed.
It certainly performed well fully laden on a wet day around Arnolds Quarry at Leighton Buzzard and out on the road.
Generous ground clearance kept us out of trouble in the quarry: short, steep inclines on sandy ground caused no problems. Onroad performance was brisk enough to keep most drivers happy, thanks to the good torque spread. It also handled well through the endless slalom of Milton Keynes roundabouts.
Spring bias We're no fans of double-H pattern gearboxes generally, but the Merc slap-across range-change worked better than many. The spring bias is toward the 3/4 and 5/6 plane so changes across the range are easy if you let the lever settle by itself. The synchromesh allowed some surprisingly fast changes too. Even so, we can't understand why Mercedes doesn't fit its multi-wheelers with the EPS box. Given that many tippers work in hilly country the power shift would have to be a useful addition. In fact it wouldn't even be an addition—Mercedes UK-spec eight-leggers start life with an EPS gearbox which is removed before export!
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