The battle over new-car warranties is hotting up. Daihatsu has just announced that its entire UK line-up – the Terios, Copen, Sirion and Materia - will now come with five-year, unlimited mileage cover – meaning that owners should face unexpected repair bills until 2013.

The move isn’t yet permanent – it currently lasts only until the year end – and doesn’t extend to Daihatsus bought as company cars. And if you sell the car, you can’t pass the warranty on. But it boosts the choice of cars offered with warranties extending beyond the three years that most makes offer.

Kia shook up the market last year by offering seven-year/100,000-mile warranties on its Cee’d and Procee’d models, while Hyundai has for years put five-year cover across its line-up, including the £6495 i10 city car. Fiat has pitched in, too, by backing its Bravo small hatchback with five-year cover.

Daihatsu’s move followed a trial at the start of the year, when it put five-year cover on its Sirion and Terios. Sales this year across the four models have risen by a third so far, so the make is eager to build on this.