If the OEM factory fit tyres were 96 load rating and speed rating Y and they have been replaced with load rating 92 and speed rating Y you have a problem. Should you have an accident your insurers will very possibly refuse to pay out on your claim.

If I were you I would insist that the garage replce them with tyres of the correct spec. If they refuse check with your insurers and see if they will still cover you with lower rated tyres.

There is also a strong possibility that if you were involved in a serious accident and a tyre was to blame you would be prosecuted.

A 92 load index gives you 630kg per tyre, which with four tyres gives you a weight limit of 2520kg. Your car will weight around 1500kg, so unless you are going to load the car up with 1000kg of people and luggage, you are unlikely to exceed the capacity of the tyres.

Unfortunately it does not work like that. The manufacturer specifies the load rating, the owner cannot decide to change simply because it appears that a cheaper tyre will do the job.

The load rating is not simply a static measurement, there is far more to it than that. Manufacturers employ engineers to carry out these calculations, its is not something you can change by simply adding four numbers together on a beermat.

Your four tyres are your cars only connection with the road. Buying cheaper tyres with is lower load rating may save a few pounds but could end up costing you far more.

Don't tell people to do what is unsafe.

All cars are homologated with a range of wheels and tyres dependant upon engine and trim spec. 15" or 18" they will have pretty much the same speed and load rating. If you upgrade it is normally acceptable provided that the new tyres have at least the same speed and load rating but any change form the factory fit needs telling to your insurers.

Downrating for either speed or load rating is not acceptable except for winter tyres where insurers will normally allow you to drop down a speed rating provided its still above the max speed of the car. Considering that the differences in price between a H and V rated tyres are tiny and likewise the difference between a 92 and 96 rated tyre are tiny (on Camskills site a Continetal 96Y is £7.80 more than a 92Y) you would have to be clinically insane not to match the OEM spec.

Unlike some countries, there's no requirement in the UK to fit speed rated tyres to match original specification, nor indeed to match the car's top speed.

There may be no legal requirement in the UK if you start reading to law to the letter but that does not stop any insurance assessor and the Police checking the tyres after an accident.

What is better, arguing the point in court or simply spening a few extra pounds on the correct spec tyres.

It not like we are talking hunreds of pounds here, H or V for my car makes about a tenner for a set of 4.