I have a new car on order, but it's not available until September.

My current car is on good condition winter tyres, but it will need four new tyres if I go onto summer-grade tyres. I've only offered £1200 p/e by dealer, so I'm reluctant to spend any money on it.

Not prepared to compromise safety though, so would I buy good tyres if necessary. What is your advice? Most journeys are short-distance, but I have a 400-mile trip in late June. I'm concerned about insurance liability and the safety of my wife and myself.