More ANpower less noise
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• MAN has launched a new range of five, six and 10cylinder engines for its F90 heavy truck with more power and torque and lower noise and emissions — but as yet there is no definitive word on when they will arrive in the UK. With the latest power units stretching from 198 to 368kW (270-500hp), MAN has become the second truck manufacturer to launch a 368kW tractor on the Continent within a month.
A fortnight ago Renault unveiled its futuristic AE tractor range (CM 31 May-6 June) with a 370kW (503hp) version of the 16-litre EE9 Mack veeeight.
Now MAN has uprated its mighty 18-litre vee-10 engine currently fitted in the top-ofthe-range 19.462 tractor to push out 368kW and a massive 2,350Nm (1,7331bft) of torque — 17% more than the Renault and 8% more than the Volvo F16-485, previously heralded as the most powerful tractor in Europe in terms of peak torque with 2,160Nm (1,5931bft).
Five-cylinder range
While the arrival of the 19.502 tractor will undoubtedly grab the headlines for MAN, the latest mid-range five-cylinder engines arguably have the greatest significance for UK hauliers. The 191kW (256hp) 10-litre charge-cooled block, currently available in the right-hand-drive 17.262/22.262 two and threeaxle tractors and the 30.262 lightweight eight-legger, has now been reworked to develop 198kW (270hp) and 235kW (320hp) in the D265 LF 02 and D2685 LF 03 versions with peak torques of 1,130Nm and 1,370Nm (833 and 1,010Ibft) respectively. The lowest-powered LF02 engine is coupled to either a ZF Ecomid box or TwinSplitter, while the LF03 gets the ZF Ecosplit or TwinSplitter box.
When the 10-litre engine was originally launched in 1987, MAN declared its 191kW was "a conservative rating" and there was potential to take it significantly higher. The new five-cylinder's power boost comes from a modified combustion process with the torroidal bowl in the piston moved more towards the centre and closed in towards the crown, along with higher injection pressures and new widerspread four-hole injectors. MAN has made a number of other modifications to the block, making it more rigid, and bolting a crankcase yoke to the sump to cut down the radiation.
The oil sump has been accoustically "decoupled" by way of a bolted-on plastic shell. Other features include tappets which are offset to the camshaft in order to achieve a forced rotation giving less wear.
The engines have revised four-point mounts which reduce the amount of vibration transferred to the chassis and cut down noise even further.
However, the greatest advantage of the five-cylinder D2865 engine over the heavier 12-litre six-cylinder engine previously used in MAN's lowerpowered F90 trucks is its moderate weight of 830kg. This together with its higher output, means that the new MAN 19.322 tractor with the 235kW D2865 LF03 is now a strong contender against other 10-litre-engjned fleet tractors such as the Iveco Ford 190.32, Volvo FLIO and ERF E 10 with the Cummins LTAA10-325.
While no official decision has been taken, it looks likely that the existing right-hand-drive 30.262 eight-wheeler and 17.262/22.262 tractors will eventually be phased out next year in favour of F90 models with the high-powered fivecylinder engine_ Given the 10-litre's powerto-weight advantage, it also makes sense for MAN-VW to drop the heavier 30.292 and 30.332 tour-axle rigids and 17.292/17.332 with the 12litre-engine in favour of fivecylinder equivalents.
Six-cylinder engines
Many of the internal features found on the uprated fivecylinder engines are incorporated in the latest in-line-six F90 power units. The previously most-powerful 265kW (356hp) 19.362 12-litre tractor has been replaced by the uprated 272kW (370hp) 19.372 and the all new 309kW (420hp) 19.422 artic with torque outputs of 1,520Nm (1,1211bft) and 1,730Nm (1,2761bft) respectively.
Both the 19.372 and 19.422 come with the choice of a ZF synchro transmission or the Eaton TwinSplitter box.
MAN is aiming the more powerful charge-cooled 12-litre engines at those hauliers looking for greater productivity, rather than just good economy, but with a minimum fuel consumption of 190g/kWh it believes the 19.422 tractor will still be attractive to costconscious operators.
There are no concrete plans for the UK, although one option open to MAN-VW is to drop the current 17.362 in favour of the more powerful 19.372/422 tractors, as well as dee 17.332 but not the latter with a comparable model on the grounds that those operators wanting a tractor in the 238-253kW (320-340hp) bracket will opt for the fighter fivecylinder version.
From next year, as expected, MAN will start fitting the Bosch Electronic Diesel Control system (EDC) on its most powerful 12-litre E90 tractor following the example of Scania and Volvo.
Vee-10 engine
With the arrival of the mighty D2840 LF01V power unit, MAN has boosted the power in its flagship F90 vee-engined tractor by close to 9% and torque by almost 13%. Technical improvements include a modified combustion process with high-pressure injection through four-hole injectors. As in the five and sixcylinder engines, the torroidal bowl in the piston crown has been slightly moved and the vee block's twin turbochargers have also been resited, cutting the overall engine length by 170mm. There is also a twopiece exhaust manifold of new material, a plastic case for the sump, revised intake ducting and a reinforced mechanical centrifugal timing device.
The vee-10's rated engine speed has been cut from 2,000 to 1,900rpm to ensure that it meets anti-noise regulations required by EEC 84/424.
MAN-VW has no timetable for the British launch of the 17,502, beyond saying that it could be seen "at the very earliest" at the Motor Show in September — although RHD. delivery will not be until 1991.
At the launch of its engines last week, MAN laid great emphasis on the fact that all of them comply with the forthcoming EEC 88/77EWG exhaust regulations due to come into force on 1 October. And with respect to gaseous emissions and particulates it claims they are noticably below other limits.
Among the vehicles on display were a number of lownoise "Silent" models developed primarily to overcome Austrian legislation (CM 24-30 August 1989).
However, MAN engineering boss Klaus Schubert reported
to journalists last week that in the battle to reduce oxides of nitrogen (N0x) from diesel exhaust there would inevitably be some trade-off in fuel economy of between 2 and 5% as well as an increase in the level of CO2. A fully electronicallycontrolled injection system could offset that loss.
Driving impressions
Commercial Motor took the opportunity to try out lefthand-drive versions of the latest F90 models last week over a short road course in Wurzberg, West Germany, with all the vehicles running laden.
The 19.322 certainly showed itself to be a serious rival to equivalent fleet tractors on the market.
The 10-litre engine is a willing worker pulling strongly on gradients. With peak torque delivered between 1,000 and 1,500rpm it proved flexible enough although the best progress was made operating at the higher limit, Most noticeable was how quiet the five-cylinder engine is even when lugging down to 1,000rpm. Coupled to a 16speed ZF Ecosplit it happily took half gears at 1,7001, 80Orpm.
Running up a long 7% gradient, the 19.422 tractor showed the kind of hill-climbing power exhibited by the likes of the Volvo F12-400.
Inevitably the easiest truck to drive was the 19.502. Coupled to a 13-speed Fuller Roadranger (the ZF is an option but the Twin Splitter is not), the 19.502 combination romped up motorway banks in top with no need for splits and pulled like the proverbial train. MAN has again raised the stakes in the high-power tractor arena with the uprated vee-10. The 19.502 is well on a par with the 17.48 Mercedes and Scania 143.470 although few UK hauliers will be able to justify its purchase, especially with the arrival of the uprated 12litre models.