Diesel. Look back just a couple of years and public perception was that this was a fuel reserved for farmers, truck drivers and the economy-minded motorist.

But it is astonishing how effectively – and quickly – diesel pioneers like PSA and VW Group have turned committed petrolheads: analysts are convinced that within two years the UK new car market will be more than 50% diesel, having caught up with what the continent has known for years: modern oil-burners are not slow, dirty or noisy.

The undersigned, having recently transferred from the rarified atmosphere of Revs magazine, is still in the unleaded camp, and wasn’t looking forward to the prospect of testing Seat’s 1.9 TDi PD, even though it has a Cupra badge. The Leon is, in fact, a slick looking motor, with street credible front and rear bumpers, a larger than standard rear spoiler and a decent set of five-spoke 17in rims. All this and 52mpg?

The sports theme continues inside with supportive seats, white dials, and a top sound system that will appeal to younger drivers. On the road the Cupra is a hoot. There’s plenty of power up to the five-grand red line… snick a lower gear from the positive six-speed box, plant the right foot and the 150bhp four-cylinder pulls just as strongly. Even throwing it hard into the bends doesn’t disturb the perfectly set up handling. If things do get fruity, traction control brings back the grip. Because of its youth appeal – and the power of the Cupra badge – Seat could be the brand that converts young sniffers to the sensibilities of diesel.

Strengths: Great diesel engine, Cupra handling
Weakness: You let us know
Opportunity: To convert petrolheads
Threat: Rising diesel pump prices
The USP: Quick – but economical
Price: £16,015
Engine: 1.9 TDi PD 150bhp, 236lb-ft @ 2,000rpm
Transmission: 6spd manual, fwd
Performance: 8.2sec, 134mph
Efficiency: 52.3mpg /146g/km
Service intervals: 10,000 miles
CAP RV (3yr/30k): £6,150 (39%)
Rivals: VW Golf, Audi A3, Mazda3