No problem with that - if the car was newer the fully synth oil would be specified anyway. It'll be a little more expensive though, and keep an eye on the oil consumption as the new oil is thinner.
John
John
I can't see the point in DIY Spanner using thinner oil in a high mileage Punto. Normally you'd use a thicker grade.
but if most wear occurs when cold, that's when a 0W or 5W will circulate better.