An SUV studded tyres is great on all winter surfaces if you have been taken care of the tyre. In order for the tyre to have excellent grip and control, you will need to make sure that you have sufficient tread depth, correct tyre pressure, that the studs are still in its place and that there is no excessive wear. Winter tyres should always be used if you have winter conditions or even if you have sub-zero temperatures, as the rubber in summer tyres will become hard and will not be able to provide you with the grip and control that you are expecting from your tyres.
If your tyres don’t have the mountain snowflake symbol on the sidewall, then they are not approved for winter use and you should avoid driving if you have cold weather or snowy, icy or slushy roads. You will not have any control over your vehicle as you will have no grip.
Wrong tyre pressure will cause your SUV to consume more fuel when you drive and the tyre wear will increase, so checking your tyre pressure can save you a lot of money, both short term and long term.