How does the Proton X50’s three-cylinder engines stay so smooth and quiet?



Three-cylinder engines are notorious for their excessive vibrations, due to the unbalanced forces acting on the crankshaft – according to the armchair experts, at least. When Proton announced that the highly-anticipated Proton X50 would be equipped with a three-cylinder engine on all variants, you could almost hear the collective gasps of the keyboard warriors online.

However, during our test drive session for the Proton X50 at the Sepang International Circuit yesterday, we could barely discern any vibrations from the engine while being seated inside the cabin. Without looking underneath the bonnet, you’d probably even forget the number of cylinders on your engine.

So what makes this engine so special that it has supposedly solved the kryptonite of a three-pot mill? According to Proton, the engine features more than 10 parts that are designed specifically to combat NVH.

These include the dual-mass flywheel with centrifugal pendulum absorber damper, balancing shaft, low noise timing belt, high stiffness engine block and oil pan, silent fuel pump and injectors, as well as engine compartment vibration dampeners.

Proton X50 Chief Engineer, Noor Hisham Ismail, explaining the improvements made on the engine specifically to combat NVH.

These measures have all been developed throughout Volvo’s extensive experience in making odd-number cylindered engines – such as the inline-five Modular Engine – and are now passed on to newer engines developed together with Geely, to be used in various applications within the greater Geely family.

The specialised engine is complemented by impressive noise insulation in the cabin, which almost completely eliminated any grating noises or unpleasant vibrations while driving. Granted, our short test drive sessions did not include any real-world driving situations, so we still cannot truly comment on the road noises seeping into the cabin. But from what we’ve experienced so far, we have quite high hopes on that aspect as well.

No pricing or release dates have been announced for the Proton X50 just yet, but we are expecting to hear them very soon. To recap, the Proton X50 will be offered in four variants – Standard, Executive, Premium, and Flagship – with two engine choices – 1.5T on the four lower variants, and a 1.5TGDi engine on the Flagship variant.

The two powertrain options are based on the same 1.5-litre three-cylinder turbocharged engine, though the 1.5T gets port fuel injection, while the 1.5TGDi variant features direct injection. In terms of output, the 1.5T makes 150 hp and 226 Nm of torque, while the 1.5TGDi kicks it up a notch with 177 hp and 255 Nm.

Both engines on the Proton X50 are paired to a seven-speed dual-clutch gearbox – similar to the one on the CKD X70, though slightly tuned to better fit the new 1.5-litre engine, weight, as well as driving characteristics of the X50.