Latest:
TOUGH HEAVYWEIGHT
00:00 21 Jul 1994
|
Truck sales have been bumping along the bottom of the graph for
more than four years. But models put into development before the
trough began are hitting the dealers now. Some were launched
quietly last year when sales looked as if they might perk up. No
girls, no fanfares, precious little champagne. Just a discreet
column or two in the trade press. And the punters responded by
staying away in droves. Not really: there has been an upsurge in
multiwheeled tipper sales.
Mercedes-Benz launched two new multiwheelers last year. The 3234 was brought out later than the 2527B we test here, but both were significant launches. The 2527B would appear to offer 25t and 270bhp, but in fact it is rated at 26t GVW. The eight-legger offers 32t GVW and 340bhp, so its badging is spot on.
We decided to test the six-legger because it was an opportunity to get our hands on a Euro-1 engined 6x4 tipper from a major player in the heavy league.
The old-style multiwheelers from M-B used naturally aspirated vee-configuration diesels. They were considered worthy, dull and reliable, but slow and heavy compared to the opposition. The Euro-1 requirements opened the door for a rake of improvements.
Out went the 2422's naturally aspirated 11-litre vee-six. In came the 9.6-litre charge-cooled vee-six, which although smaller puts the power up by 23%. Handy!
But the real key to the improvement is the torque - up by 39%. Even if M-B had done no more than throw the new engine in the old chassis it would have been an improvement. Chuck in the 1.6t increase in GVW and it is considerably better.
You also get two more gear ratios to play with. An eight-speed synchromesh range change plus deep crawler gearbox replaces the old six-speed cog swapper. Our test unit was set up for 96km/hr (60mph) on its speed limiter, but production units will be set for 90km/hr (56mph). Standard rear axle ratio is 3.715:1, but there are alternative choices of 3.968 or 4.143. The lowest ratio would give stump-pulling ability in, say, the Derbyshire Dales, which of course is prime tipper country with all those quarries!
M-B says gradeability goes 42% for the high ratio axle, 45% for the middle ratio and 47% for the stump puller. The rest of the driveline and suspension is 'as you were'. The rear axle double-drive bogie has cross and inter-axle diff locks as standard. Suspension is by a parabolic, multi-leaf, two-spring rear bogie, which looks as if it could handle off-road work. The front carries parabolic springs and an anti-roll bar for good measure.
M-B obviously believes the chassis is sturdy enough, and there's no flitching. Mind you, it's heavy enough as it is. The ladder-type frame carries a hefty steel front bumper - handy in the queue for the weighbridge.
There is a re-sited vertical exhaust stack, and automatic chassis lubrication is standard. The exhaust has in fact been moved closer to the cab, reflecting the narrower cab-body clearance, which seems to be militated by the 26t limit and its low axle-loading tolerances. The test vehicle had a Wilcox Wilcolite body and Drum underfloor tipping gear.
Productivity
An overall fuel consumption of 33.8lit/100km (8.36mpg) is not outstanding for a 6x4, but it needs to be looked at in context. The earlier M-B 2421 returned just 8.13mpg on tests around the same route. But the 2527B carries an extra 1.6t and is powered by a smaller yet more powerful engine which also meets Euro-1 emissions regulations. Any reduction in fuel consumed under those circumstances is praiseworthy. So far as average speed is concerned there was hardly a whisker between one average and another.
Although the 2527 carries that extra 1.6t, it has got a little more podgy in the process, presumably in an effort to cope with the extra gross weight. A fully fuelled 2527 chassis cab tips the scales at 7.57t compared with our test 2421, which came in at just 7.2t. A Scania P93 is similarly hefty, but Foden's 3300 series starts around 500kg lighter.
On the road
Fire up the 2527 and you notice the difference immediately. Gone is the cab-shaking chug of the naturally aspirated unit; instead the new smaller turbo-charged vee-six sounds more like its bigger brother as fitted to the LEV range. It is very smooth and free-revving, even if it does not feel quite as refined as the 11-litre unit.
Torque output is good and never drops below 1,000Nm between 950 and 1,800rpm, so it is no bother to drive in hilly country. In any case, even if the torque spread was narrow it would be no chore because the gearchange is so good. The slap-across range change all-synchro gearbox is one of the best synchro boxes around. It is light and nearly as quick as a constant mesh, with little baulking either up or down the steps.
The combination of torque spread and the user-friendly gearbox helped the 2527 to a creditable 2min 38sec climb up the Edge Hill dog-leg - more than 30 seconds faster than its predecessor. It also managed a re-start on MIRA's 33% test hill in first gear. The crawler ratio was always there in reserve if needed.
M-B has also broken with tradition and got rid of the clipper-ship size steering wheel. Even so, the wheel used is quite large enough for a small yacht! However, although the steering displays a slight vagueness round the straightahead, it's quite positive enough to make good progress along a twisty road. Roll is not a problem, and there is lots of confidence-inspiring grip.
If you want air-suspended seats then you can order them as options, but the standard mechanically-sprung items are perfectly acceptable. They deliver a reasonable compromise between keeping your seat and keeping your backbone in one piece over rough terrain.
The M-B constant throttle exhaust brake is optional on the 2527 and is well worth the extra expense if you operate in hilly country. The standard exhaust brake is not terribly efficient, even if you throw in a downshift.
The service brakes are good. At MIRA they pulled up the truck without wheel-locking, but the stopping distances were not especially impressive.
Cab comfort
1994 is a big year for M-B's SK cab because it is 21 years old. But M-B probably won't be throwing a party! Joking apart, the cab has aged pretty well, with the odd cosmetic tweak every now and then.
But cosmetics is not the real issue here. Weight is. The chassis cab has gained around 400kg in five years, which is sapping payload capacity. If M-B chose to utilise the LN2 cab from the 814 it would suit the job and save quite a bit of weight in the process. It depends on whether or not the vee engine would fit under the smaller cab without major surgery. But it could cut weight, cut prices and suit tippermen well!
Having said all that, the SK cab is pretty comfortable for a day's work. But two steps up is a bit of a stretch and three would be easier. The folding bottom step is a good idea provided it keeps out of harm's way on rough going.
Once you've climbed up there are no surprises. The steering wheel adjusts for height and reach and the rest of the controls are just like other big Mercs. There is the same dashboard with the same instruments and the steering column with the same infuriating multi-function stalk. There are too many functions for a single stalk: you need a degree in rocket science just to turn the wipers on.
Enough carping: this isn't a bad cab, and visibility is on the whole good. It has a window to the rear, a standard kerbview mirror and heated door mirrors too. But the view to the driver's front quarter is partly obscured by the mirror on that side.
There are door pockets in both doors and a wide one across the cab rear. Documents can be stowed in a cubby over the windscreen - it's even got an elastic band to stop things falling out.
The dashboard is trimmed in M-B's usual brown/black plastic, and the floor and engine hump have black rubber coverings. So it should be easy to wash out when on dirty sites.
Conclusion
The 2527 is a definite improvement over its predecessor and is a good, if heavy, 6x4 chassis. If it had the smaller, lighter LN2 cab it would be even better. Performance-wise it has got a wide torque spread, which confers good lugging ability, but a race-car it ain't. Nevertheless it has a nice gearbox and is a pleasant drive. It's also at the top of its price bracket, but it has got chassis autolube as standard.
Weightwise it is not good news unless your operation is mainly off-road. Here its undoubted robustness would be an advantage but is unlikely to appeal to on-road users. M-B has cut its tractor units down to size: perhaps it's time it went to work on its multiwheelers.
Details: enter 700 on card
OPERATIONAL TRIAL RESULTS
Motorways: Average speed, 83.2km/h (51.7mph); fuel consumption, 34.1lit/100km (8.28mpg)
A-roads: Average speed, 56.1km/h (34.9mph); fuel consumption, 33.6lit/100km (8.41mpg)
ACCELERATION
km/h Sec Gear(s)
0-80 62.6
32-64 26.2 5th/7th
48-80 38.7 6th/7th
IN-CAB NOISE
km/h dB(A) rpm
64 70.4 1,250
80 75.5 1,550
96 75.8 1,825
TURNING CIRCLE
Left lock 21.19m between kerbs
22.37m between walls
Right lock 20.70m between kerbs
21.88m between walls
BRAKE PERFORMANCE
From km/h Peak(g) Average(g) Distance(m)
32 0.69 0.47 10.8
48 0.65 0.45 20.3
64 0.67 0.47 34.7
WEIGHTS
Kerbweight as tested with full tank (chassis cab only) 7.57t
Bodywork 1.79t
Net payload 16.64t
Total 26.00t e
From km/h Peak(g) Average(g) Distance(m)
32 0.69 0.47 10.8
48 0.65 0.45 20.3
64 0.67 0.47 34.7
MODEL: Mercedes-Benz 2527B 6x4 tipper/mixer rigid chassis.
Design GVW: 26t.
Importer: Mercedes-Benz (UK) Ltd, Tongwell, Milton Keynes, MK15 8BA.
ENGINE: Mercedes-Benz OM401LA, direct- injection, charge-cooled diesel.
Cylinders: Six, in-vee.
Bore/stroke: 125mm/130mm.
Capacity: 9.57lit.
Compression ratio: 16.75:1.
Maximum net power: 200kW (268hp) at 2,100rpm.
Maximum net torque: 1,090Nm (804lbft) at 1,200rpm.
TRANSMISSION: Mercedes-Benz G155-9/15 eight-speed synchromesh plus crawler, range change.
Final drive: 3.77:1 for 96km/h (60mph) geared speed. Later models geared for 90km/h (56mph); 3.715:1. Optional ratios: 3.968:1, 4.143:1.
Clutch: Hydraulically actuated single dry plate with air assistance. Diameter: 430mm.
BRAKING SYSTEMS: Dual circuit, full air with load sensing on rear axles. Automatic slack adjusters and air dryer.
Parking: Spring brake actuators on rear axles.
Exhaust: Air actuated by foot control.
Brake dimensions: Drum diameter, all axles: 410mm. Drum width, all axles: 180mm.
STEERING: Mercedes-Benz recirculating ball with integral power assistance.
CHASSIS: Ladder type high tensile steel frame with channel section side members and top hat section cross members. Steel front bumper.
Suspension: Front axle: Parabolic leaf springs with telescopic shock absorbers and anti-roll bar. Rear axles: Two spring bogie with parabolic springs.
Outer axle spread: 5.2m.
Axle design weights: front: 7.5t; rear bogie: 20t.
Design GTW: 29.5t.
Wheels and tyres: Front: 9.00 x 22.5 in drop centre wheels with 315/80R 22.5 tubeless tyres. Rear: 8.25 x 22.5 drop centre wheels with 11R 22.5 tubeless tyres.
Fuel tank: 210lit.
ELECTRICAL SYSTEMS: 24V.
Batteries: 2x12V, 135Ah.
Generator: 28V/55A alternator.
BODY: Wilcox Wilcolite aluminium body. Drum underfloor tipping gear.
TERMS OF WARRANTY: One year unlimited distance with second year driveline cover up to 200,000km. Optional second and third year extended warranty available.
DEALERS AND SERVICE POINTS: Mercedes-Benz has 102 service points in the UK.
Mercedes-Benz launched two new multiwheelers last year. The 3234 was brought out later than the 2527B we test here, but both were significant launches. The 2527B would appear to offer 25t and 270bhp, but in fact it is rated at 26t GVW. The eight-legger offers 32t GVW and 340bhp, so its badging is spot on.
ADVERTISEMENT
We decided to test the six-legger because it was an opportunity to get our hands on a Euro-1 engined 6x4 tipper from a major player in the heavy league.
The old-style multiwheelers from M-B used naturally aspirated vee-configuration diesels. They were considered worthy, dull and reliable, but slow and heavy compared to the opposition. The Euro-1 requirements opened the door for a rake of improvements.
Out went the 2422's naturally aspirated 11-litre vee-six. In came the 9.6-litre charge-cooled vee-six, which although smaller puts the power up by 23%. Handy!
But the real key to the improvement is the torque - up by 39%. Even if M-B had done no more than throw the new engine in the old chassis it would have been an improvement. Chuck in the 1.6t increase in GVW and it is considerably better.
You also get two more gear ratios to play with. An eight-speed synchromesh range change plus deep crawler gearbox replaces the old six-speed cog swapper. Our test unit was set up for 96km/hr (60mph) on its speed limiter, but production units will be set for 90km/hr (56mph). Standard rear axle ratio is 3.715:1, but there are alternative choices of 3.968 or 4.143. The lowest ratio would give stump-pulling ability in, say, the Derbyshire Dales, which of course is prime tipper country with all those quarries!
M-B says gradeability goes 42% for the high ratio axle, 45% for the middle ratio and 47% for the stump puller. The rest of the driveline and suspension is 'as you were'. The rear axle double-drive bogie has cross and inter-axle diff locks as standard. Suspension is by a parabolic, multi-leaf, two-spring rear bogie, which looks as if it could handle off-road work. The front carries parabolic springs and an anti-roll bar for good measure.
M-B obviously believes the chassis is sturdy enough, and there's no flitching. Mind you, it's heavy enough as it is. The ladder-type frame carries a hefty steel front bumper - handy in the queue for the weighbridge.
There is a re-sited vertical exhaust stack, and automatic chassis lubrication is standard. The exhaust has in fact been moved closer to the cab, reflecting the narrower cab-body clearance, which seems to be militated by the 26t limit and its low axle-loading tolerances. The test vehicle had a Wilcox Wilcolite body and Drum underfloor tipping gear.
Productivity
An overall fuel consumption of 33.8lit/100km (8.36mpg) is not outstanding for a 6x4, but it needs to be looked at in context. The earlier M-B 2421 returned just 8.13mpg on tests around the same route. But the 2527B carries an extra 1.6t and is powered by a smaller yet more powerful engine which also meets Euro-1 emissions regulations. Any reduction in fuel consumed under those circumstances is praiseworthy. So far as average speed is concerned there was hardly a whisker between one average and another.
Although the 2527 carries that extra 1.6t, it has got a little more podgy in the process, presumably in an effort to cope with the extra gross weight. A fully fuelled 2527 chassis cab tips the scales at 7.57t compared with our test 2421, which came in at just 7.2t. A Scania P93 is similarly hefty, but Foden's 3300 series starts around 500kg lighter.
On the road
Fire up the 2527 and you notice the difference immediately. Gone is the cab-shaking chug of the naturally aspirated unit; instead the new smaller turbo-charged vee-six sounds more like its bigger brother as fitted to the LEV range. It is very smooth and free-revving, even if it does not feel quite as refined as the 11-litre unit.
Torque output is good and never drops below 1,000Nm between 950 and 1,800rpm, so it is no bother to drive in hilly country. In any case, even if the torque spread was narrow it would be no chore because the gearchange is so good. The slap-across range change all-synchro gearbox is one of the best synchro boxes around. It is light and nearly as quick as a constant mesh, with little baulking either up or down the steps.
The combination of torque spread and the user-friendly gearbox helped the 2527 to a creditable 2min 38sec climb up the Edge Hill dog-leg - more than 30 seconds faster than its predecessor. It also managed a re-start on MIRA's 33% test hill in first gear. The crawler ratio was always there in reserve if needed.
M-B has also broken with tradition and got rid of the clipper-ship size steering wheel. Even so, the wheel used is quite large enough for a small yacht! However, although the steering displays a slight vagueness round the straightahead, it's quite positive enough to make good progress along a twisty road. Roll is not a problem, and there is lots of confidence-inspiring grip.
If you want air-suspended seats then you can order them as options, but the standard mechanically-sprung items are perfectly acceptable. They deliver a reasonable compromise between keeping your seat and keeping your backbone in one piece over rough terrain.
The M-B constant throttle exhaust brake is optional on the 2527 and is well worth the extra expense if you operate in hilly country. The standard exhaust brake is not terribly efficient, even if you throw in a downshift.
The service brakes are good. At MIRA they pulled up the truck without wheel-locking, but the stopping distances were not especially impressive.
Cab comfort
1994 is a big year for M-B's SK cab because it is 21 years old. But M-B probably won't be throwing a party! Joking apart, the cab has aged pretty well, with the odd cosmetic tweak every now and then.
But cosmetics is not the real issue here. Weight is. The chassis cab has gained around 400kg in five years, which is sapping payload capacity. If M-B chose to utilise the LN2 cab from the 814 it would suit the job and save quite a bit of weight in the process. It depends on whether or not the vee engine would fit under the smaller cab without major surgery. But it could cut weight, cut prices and suit tippermen well!
Having said all that, the SK cab is pretty comfortable for a day's work. But two steps up is a bit of a stretch and three would be easier. The folding bottom step is a good idea provided it keeps out of harm's way on rough going.
Once you've climbed up there are no surprises. The steering wheel adjusts for height and reach and the rest of the controls are just like other big Mercs. There is the same dashboard with the same instruments and the steering column with the same infuriating multi-function stalk. There are too many functions for a single stalk: you need a degree in rocket science just to turn the wipers on.
Enough carping: this isn't a bad cab, and visibility is on the whole good. It has a window to the rear, a standard kerbview mirror and heated door mirrors too. But the view to the driver's front quarter is partly obscured by the mirror on that side.
There are door pockets in both doors and a wide one across the cab rear. Documents can be stowed in a cubby over the windscreen - it's even got an elastic band to stop things falling out.
The dashboard is trimmed in M-B's usual brown/black plastic, and the floor and engine hump have black rubber coverings. So it should be easy to wash out when on dirty sites.
Conclusion
The 2527 is a definite improvement over its predecessor and is a good, if heavy, 6x4 chassis. If it had the smaller, lighter LN2 cab it would be even better. Performance-wise it has got a wide torque spread, which confers good lugging ability, but a race-car it ain't. Nevertheless it has a nice gearbox and is a pleasant drive. It's also at the top of its price bracket, but it has got chassis autolube as standard.
Weightwise it is not good news unless your operation is mainly off-road. Here its undoubted robustness would be an advantage but is unlikely to appeal to on-road users. M-B has cut its tractor units down to size: perhaps it's time it went to work on its multiwheelers.
Details: enter 700 on card
OPERATIONAL TRIAL RESULTS
Motorways: Average speed, 83.2km/h (51.7mph); fuel consumption, 34.1lit/100km (8.28mpg)
A-roads: Average speed, 56.1km/h (34.9mph); fuel consumption, 33.6lit/100km (8.41mpg)
ACCELERATION
km/h Sec Gear(s)
0-80 62.6
32-64 26.2 5th/7th
48-80 38.7 6th/7th
IN-CAB NOISE
km/h dB(A) rpm
64 70.4 1,250
80 75.5 1,550
96 75.8 1,825
TURNING CIRCLE
Left lock 21.19m between kerbs
22.37m between walls
Right lock 20.70m between kerbs
21.88m between walls
BRAKE PERFORMANCE
From km/h Peak(g) Average(g) Distance(m)
32 0.69 0.47 10.8
48 0.65 0.45 20.3
64 0.67 0.47 34.7
WEIGHTS
Kerbweight as tested with full tank (chassis cab only) 7.57t
Bodywork 1.79t
Net payload 16.64t
Total 26.00t e
From km/h Peak(g) Average(g) Distance(m)
32 0.69 0.47 10.8
48 0.65 0.45 20.3
64 0.67 0.47 34.7
MODEL: Mercedes-Benz 2527B 6x4 tipper/mixer rigid chassis.
Design GVW: 26t.
Importer: Mercedes-Benz (UK) Ltd, Tongwell, Milton Keynes, MK15 8BA.
ENGINE: Mercedes-Benz OM401LA, direct- injection, charge-cooled diesel.
Cylinders: Six, in-vee.
Bore/stroke: 125mm/130mm.
Capacity: 9.57lit.
Compression ratio: 16.75:1.
Maximum net power: 200kW (268hp) at 2,100rpm.
Maximum net torque: 1,090Nm (804lbft) at 1,200rpm.
TRANSMISSION: Mercedes-Benz G155-9/15 eight-speed synchromesh plus crawler, range change.
Final drive: 3.77:1 for 96km/h (60mph) geared speed. Later models geared for 90km/h (56mph); 3.715:1. Optional ratios: 3.968:1, 4.143:1.
Clutch: Hydraulically actuated single dry plate with air assistance. Diameter: 430mm.
BRAKING SYSTEMS: Dual circuit, full air with load sensing on rear axles. Automatic slack adjusters and air dryer.
Parking: Spring brake actuators on rear axles.
Exhaust: Air actuated by foot control.
Brake dimensions: Drum diameter, all axles: 410mm. Drum width, all axles: 180mm.
STEERING: Mercedes-Benz recirculating ball with integral power assistance.
CHASSIS: Ladder type high tensile steel frame with channel section side members and top hat section cross members. Steel front bumper.
Suspension: Front axle: Parabolic leaf springs with telescopic shock absorbers and anti-roll bar. Rear axles: Two spring bogie with parabolic springs.
Outer axle spread: 5.2m.
Axle design weights: front: 7.5t; rear bogie: 20t.
Design GTW: 29.5t.
Wheels and tyres: Front: 9.00 x 22.5 in drop centre wheels with 315/80R 22.5 tubeless tyres. Rear: 8.25 x 22.5 drop centre wheels with 11R 22.5 tubeless tyres.
Fuel tank: 210lit.
ELECTRICAL SYSTEMS: 24V.
Batteries: 2x12V, 135Ah.
Generator: 28V/55A alternator.
BODY: Wilcox Wilcolite aluminium body. Drum underfloor tipping gear.
TERMS OF WARRANTY: One year unlimited distance with second year driveline cover up to 200,000km. Optional second and third year extended warranty available.
DEALERS AND SERVICE POINTS: Mercedes-Benz has 102 service points in the UK.
ADVERTISEMENT
Most Viewed Articles
ADVERTISEMENT