While most CF tractors and multiwheel rigids will use the brand new 10.8-litre MX-11 engine, LF models and the lighter CF rigid chassis will continue to be powered by Cummins-supplied ISB four- and six-cylinder common-rail engines.
As usual, these are rebadged for use in DAFs, with the new four-cylinder, 4.5-litre ISB becoming a Paccar PX-5, replacing the Euro-5 Paccar FR. The six-cylinder, 6.7-litre ISB in DAFs is dubbed the Paccar PX-7, replacing the Euro-5 Paccar GR.
Cummins revealed these engines a year ago. The six-cylinder ISB/MX-7 is a straightforward development of the Euro-5 ISB, featuring the addition of EGR and variable geometry turbocharging (VGT), followed by the usual Euro-6 comprehensive SCR and DPF exhaust after-treatment box.
However, the four-cylinder ISB/MX-5 is not based on the Euro-5 ISB: it is instead derived from Cummins’ 3.8-litre ISF engine, enlarged to 4.5-litres. Cummins says this gives weight savings that offset the additional weight of the exhaust after-treatment. This engine also employs VGT and uses both EGR and SCR. It is be made in China instead of Darlington, where ISB engines currently are built.
The power and torque ratings of the new PX engines are broadly comparable to the FR and GR engines they replace. However, they have a wider peak torque plateau for better flexibility and the highest rating of the six-cylinder PX is 310hp, a significant hike from Euro-5’s 295hp.