PACCAR MX-13 gets common-rail system

The 12.9-liter PACCAR MX-13 has been substantially enhanced for 2013, changed enough that it’s being called a ‘next generation’ engine. The changes include common-rail fuel injection, more efficient turbocharger layout, and new electronic actuators. The new engine can be ordered now.

The MX-13, of course, is an option in both Peterbilt and Kenworth trucks, offering a wide range of horsepower ratings starting at 380 with torque offerings starting at 1450 lb ft, going to 500 hp and 1850 lb ft. It was developed to meet EPA 2013 emissions requirements as well as Europe’s Euro 6 emissions mandate that comes into force in 2014. It was introduced at the recent IAA exhibition in Hannover, Germany.

The all new common-rail fuel-injection system, maintaining injection pressures of 36,000 psi or 2500 bar, replaces an old-school unit-injector system. The improvement isn’t a matter of higher pressure, rather more accurate control of fuel injection. The result is finer fuel atomization and more ways to optimize combustion, says Peterbilt, ensuring the lowest possible fuel consumption, emissions, and noise levels.

The MX-13 is available in Peterbilt’s all new Model 579 plus the 587, 386 and 384, as well as its traditional and vocational line-up that includes the models 389, 388, 367 and 365.

It’s also available in all Kenworth class 8 models, including the T660, T680, T700, T800 and W900.

The 8.9-liter PACCAR PX-9 and 6.7-liter PACCAR PX-7 engines remain largely unchanged. The PX-9 engine is available in both medium and heavy-duty configurations with horsepower ratings from 260 to 380 hp and torque output up to 1250 lb ft. The medium-duty PX-7 engine comes in power ratings from 200 to 325 hp and up to 750 lb ft of torque.