Mild might be too strong a word to describe the revisions to Toyota’s best-selling car. The Corolla’s body-coloured grille is now neatly framed by two lines, and larger headlamps and a chunkier rear bumper round off what is a barely noticeable facelift. But the big news lies under the bonnet. The 1.4-litre diesel engine from the Yaris has been fitted, albeit with revisions to the turbocharger and ECU to boost power from 74 to 89bhp. The adoption of this small-capacity oil-burner means the outdated 89bhp, 2.0-litre diesel lump is removed from the range. Replacing a 2.0-litre engine with one of such a small capacity might seem like a rough deal for buyers, but the 1.4-litre unit produces identical power, is Euro4 emissions compliant and returns 57.6mpg instead of 49.6mpg. But torque – the key to effortless driving – falls by 19lb ft to 140lb ft. Turn the key and the new diesel is supremely refined, its civility noticeably superior to the outgoing 2.0-litre’s. A Corolla diesel is hardly a sports car, although the smaller engine improves its agility – even if the steering lacks feel and the suspension allows noticeable body roll. At least the ride is compliant and the steering wheel can now be adjusted for reach as well as rake. If economy is all, then this 1.4 diesel Corolla is a huge improvement, but 2.0 diesel owners who trade down into it will notice the performance difference. Jack Galusha

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