Kenworth is trialling the 13-litre Paccar MX engine in it T403 and T409 models at present
By Matt Wood | May 29, 2013
Kenworth has announced it is trialling the 13-litre Paccar MX engine in its T403 and T409 models at present.
The MX-equipped test units are currently operating with various companies and in a number of roles while the Kenworth engineering team monitors vehicle performance and fuel economy.
Kenworth Product Planning and Development Manager Brad May says “this is not an actually engine development program, the engine itself has been around in DAF trucks since 2007”.
But May was keen to emphasise the advantages of the MX engine and what it can offer in the Kenworth platform.
“The engine has a long flat torque curve, 1,000 to little over 1,400rpm, which means you’ve got a very flexible truck that allows [a] driver to drive in a manner that’s more fuel efficient,” he says.
The SCR Paccar MX uses a compacted graphite iron (CGI) that gives it a 200kg tare advantage over the Cummins ISX engine.
Kenworth has used the European-DAF heavy duty version of the MX while borrowing some castings from its North American MX cousin to aid in the conventional under bonnet installation.
The engine is currently being trialled in 343kW (460hp)/2,302Nm (1700lb/ft) and 380kW (510hp)/2,505Nm (1850lb/ft) guises at present with the focus being on single trailer, 19-metre pocket B-doubles and tipper and dog applications.
ATN and Owner//Driver had a chance to drive four different units in B-double and single trailer configurations at gross weights ranging from 33,000kg to 55,000kg.
Initial impressions were that the MX is indeed a capable powerplant in the T400 range, especially in the T409SAR. The MX engine in the SAR seems to be a happy marriage for 19-metre B-double and tipper and dog roles.
The light tare weight will also make the combination attractive for tipper roles and the 380kW engine seemed happiest around the 50,000kg mark.
Paccar has stuck with Eaton transmissions behind the MX and both the Ultra-shift AMT and manual versions were available for the drive.
The Ultrashift installation is neat and seems to perform well behind the Euro engine, low speed manoeuvrability and clutch engagement were better than some other Eaton AMT applications that I’ve come across.
In fact Kenworth has been experimenting with final drive ratios as tall as 3.4:1 in AMT equipped test vehicles to maximise fuel efficiency. A drive of a 343kW T409 AMT with a 3.4 diff ratio provided better than expected performance in a closed circuit environment.
There is no indication from Paccar at this stage as to when the MX powered Kenworth range will be available to prospective buyers.
