Manufacturers always overestimate the life of their belts, tensioners,
pulleys and waterpumps until there is a problem. There was with VAG belts on 1.4 16vs and 1.6 16vs because the German engineers (or their accountants) fitted plastic or nylon pulleys that failed, just as they did on GM Opel engines in the 1990s. These routinely failed at around 35k - 45k, so, rather than admit its mistake, VAG sought to profit from the situation by changing the timing belt replacement on
ALL its timing belt engines to 4 years or 40k miles, whichever comes first. It's true, some belts do last a lot longer. And what usually fails is a pulley, tensioner or waterpump driven by the belt rather than the belt itself. But I wouldn't push any beyond 5 years or 80k miles whichever came first. The VAG 1.4TSI is chain cam, with a water cooled turbo.