While the base engine on which the 1.5TD 3-cylinder powerplant was developed from (a 2.0-liter 4-cylinder unit) did consider a diesel application, it was done so to make sure it’s robust enough for high levels of turbocharging. It’s for this reason why the Geely engine, found in the Coolray, Azkarra, and Okavango produces higher outputs compared to the competition—177 horsepower and 250 Nm of torque. 

“You can’t say you can buy any engine and expect it to be a good one,” says Dr. Sandquist. “Longer durability is a requirement, and we built it in from the start. It’s for this reason why CEVT has done a lot of durability and verification tests.”

The 1.5TD was fitted to 231 test cars, traveled 120 million kilometers, and ran 50,000 hours non-stop on a test bed during development. Thanks to these tests, the engine goes above and beyond the industry standard—designed to last 15 years or a distance of 350,000 kilometers. Both are much higher than the industry standard of 10 years or 200,000 kilometers.

Peculiarly, despite the longer durability requirement for the 1.5TD engine, it does employ a timing belt instead of a timing chain. The decision to use a timing belt is down to improve the overall NVH.

“In our experience, using a timing belt is a better option. Volvo engines still use timing belts, and if it’s good enough for Volvo, it’s good enough for us,” reveals Dr. Sandquist. 

Geely recommends a timing belt replacement every 6 years or 100,000 kilometers, whichever comes first.

The company’s decision to shun away diesels shouldn’t dismay those looking for vehicles with high fuel economy, however. The Geely 1.5TD accepts electrification right from the get-go. Aside from Mild-Hybrid (MHEV) technology—the 48-volt EMS found in the Azkarra and Okavango, it also accepts full hybrid and even plug-in hybrid technology as well.

On the flip side, for those looking for performance, electrification will also help boost the 1.5TD’s power. Although the engine can be tuned up 400 horsepower, this won’t be what customers want. For Geely, the era of extracting a ton of power from a small engine is over. It’s all about “right sizing” now.

The highly modular nature of the engine as well as its capability to take on electrification from the get-go will help Geely in the long run. 

Despite all the hype surrounding electric vehicles, the internal combustion engine is here to stay. Citing the International Energy Agency’s World Energy Outlook report, Dr. Sandquist says internal combustion engines, with some degree of electrification, will exist up to 2060. With that, Geely and CEVT will continue its development. Among those in the pipeline include a high thermal efficiency engine—42.5 percent, and even a two-cylinder engine used as a range extender for electric vehicles.