12.9 litre PACCAR MX engine is fitted to the popular DAF CF85 and XF105 models.

DAF is introducing a significant number of innovations to the successful 12.9 litre PACCAR MX engine. New pistons, optimised fuel injection and a unique, fully encapsulated exhaust manifold unit ensure substantially lower fuel consumption and therefore lower CO₂ emissions. The enhancements fit well within DAF Advanced Transport Efficiency (ATe), a full range of solutions with the aim of increasing transport performance while reducing environmental impact and costs.

The 12.9 litre PACCAR MX engine is fitted to the popular DAF CF85 and XF105 models and is well-known for its high reliability and performance. The engine also has an excellent reputation for fuel efficiency. While further optimising this, DAF first concentrated on those measures that are valuable at partial load, which is how trucks drive 80% of the time.

The versions of the PACCAR MX engine delivering 265 kW/360 hp, 300 kW/410 hp and 340 kW/460 hp all have new pistons that have better thermal qualities and need less cooling. This means a smaller oil pump is sufficient for maximum efficiency and less friction loss. At the same time, the injection angles and engine management system have been optimised. DAF is the first in the truck industry to use thermal encapsulation not only for the turbocharger but also for the exhaust manifold unit. This results in even better air management by providing higher turbo efficiency and therefore better combustion. The enhancements to the PACCAR MX engine result in 3% lower fuel consumption and CO₂ emissions, depending on the application.

As part of the DAF Advanced Transport Efficiency programme, more innovations have been implemented to improve fuel efficiency and reduce CO₂ emissions and the total cost of ownership even further. The engines in the DAF CF85 and the XF105 switch off automatically after five minutes of idling, and as well as the standard 16-speed gearbox there is now also a lighter manual 12-speed gearbox available, so the driveline can be even better matched to the specific application. The high torque of the PACCAR MX engine means that a 16-speed gearbox is not always necessary. Moreover, the new gearbox now offers the option of Direct Drive for the version with 375 kW/510 hp as well, which means less friction and greater efficiency. Upon customer request, the maximum speed of the CF and XF vehicles can be increased to 89 km/h. The standard setting is 85 km/h, which provides a fuel saving of 2-3% for long distance transport applications.

Also new is an optional AS Tronic automated gearbox with a shifting strategy fully optimised for fuel consumption. The driver can only shift gears himself at speeds below 30 km/h and when using the MX Engine Brake, in all other situations the electronics decide the ideal shifting moment. To bring the importance of low fuel consumption to the attention of drivers, it is now standard for the main dashboard display of the CF and the XF series to show information about current and achieved fuel consumption.