There’s more to why this is such a significant engine.

Thomas, and clearly Ford, sees the future of mainstream diesel engines as limited – heresy to business car managers and company drivers who have tuned into the benefits of diesel both in terms of company car tax and improved running costs.

But here’s why, according to Thomas. “The next stage of Euro emissions standards, Euro 6, will require diesel engines to be more complex and expensive to build.

“Our turbocharged petrol EcoBoost engine offers the low end torque of a diesel, with the high end power of a petrol engine, so we can deliver diesel-style fuel economy without compromising performance or refinement.”

After driving the 125PS model at the engine’s launch earlier this year, it’s hard to argue against that assessment. In fact we didn’t. We decided it was so good, we name the Focus EcoBoost our Company Car of the Year – booting off the diesel version which had initially topped our thinking.

EcoBoost is a delight: refined, responsive, and economical. When you start the engine, it’s so quiet that it’s difficult to know it’s even running. When you accelerate hard, it has an urgent off-beat warble that will encourage you to keep doing more of the same.

I was intrigued, though, to know what Thomas thinks is the most successful expression of the  three-cylinder EcoBoost engine: 100PS or 125PS?

There comes that warm beam again: “My favourite is the 125PS version because of its combination of torque and power plus in real life usage you also get very good fuel economy.”

Ford’s most significant engine in 10 years?  With a €200m investment, it’s an engine tasked with a big job in spite of its diminutive size. But it’s clearly up to the task.

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Read our  business car review of the Focus 1.0 EcoBoost and why we named the Ford Focus our Best Company Car of the Year.