When the Proton X50 was launched in October this year, there was a lot of buzz surrounding the SUV’s use of a timing belt instead of a timing chain for its 1.5 litre turbocharged three-cylinder engine, which is offered in two versions: with port and direct fuel injection.

While some were unfazed by the idea of a timing belt, others lamented its usage, claiming it to be an “old” piece of technology. However, that’s not the case at all, says Håkan Sandquist, director of powertrain strategy at China Euro Vehicle Technology (CEVT).

During a recent group interview, Sandquist explained that a lot of validation work was carried out to ensure the reliability and performance of the three-cylinder engines. This includes tests at temperatures ranging from -40 to 40 degrees Celsius, altitudes of up to 4,000 metres and mileage tests of millions of kilometres.

The work performed by CEVT was necessary as the engines were designed with global markets in mind. As such, ensuring they work in the Proton X50 is just part of a larger picture, as the division within Zhejiang Geely Holding must also ensure the engines work well in other projects by Volvo Cars and Geely Auto.

“I hear the same kind of question from many places but I think when it comes to timing chains, they also requires a lot of detailed engineering expertise when developing them. Today, I’d say you see more new products actually being developed with timing belts than timing chains,” said Sandquist.

“There was one of the major OEMs of the world, I’m not going to say which one, who had significant issues with timing chains, so they actually reverted to timing belts. With a properly designed system, they will be fit for life. I don’t see there’s a big difference in the two, but they have to be properly designed,” he added.

Sandquist goes on to say that Volvo engines have been using timing belts for a long time, undergoing plenty of validating testing before they are rolled out. For instance, the current XC40 uses a timing belt in T3, T4, T5 and Recharge T5 guises. Additionally, other models like the S60, XC60 and XC90 also feature timing belts.

“If you look at all the Volvo engines, they have been using timing belts for quite a long time, they have the most stringent validation requirements and they still continue with timing belts. It’s good enough for Volvo, it’s good enough for us,” he commented.

It’s also important to note that the official service schedule for the X50 requires an inspection of its timing belt at 100,000 km/60 months, with a replacement due at 110,000 km/66 months. The timing belt for the X50 costs RM195.16, while the drive (or serpentine) belt that is also changed together is RM112.89 – the labour for both is RM150. The total cost of replacing this belts, when spread out across 60 months or five years, is about RM90 a year.

Aside from discussions on timing belts, Sandquist also noted that the three-cylinder engines were developed to run on RON 92 petrol, which is a common fuel in China. In our local context, where RON 95 and RON 97 are prevalent, it is an absolute non-issue for owners to run the former despite there being a turbocharger. He added that there’s not much to gain with running on RON 97, more so with RON 100.

Proton’s official figures for the X50 are 150 PS and 226 Nm of torque with the port fuel injection (PFI) version of the 1.5 turbo three-pot, while the direct injection (DI) unit in the range-topping Flagship makes 177 PS and 255 Nm. However, Geely has stated that the latter’s outputs are with RON 92 fuel used, and they go up to 179 PS and 265 Nm with RON 95.

“Actually, the engine has been developed for RON 92, which is normal in the Chinese market, and it will run really well with RON 95. With RON 97, there’s no real benefit. It’s only if you would be driving very much [in] super-hot climate and very high loads. But I understand that normal driving would be perfectly fine with RON 95,” explained Sandquist.