It’s essential that you check your tyre pressures regularly and this especially applies to winter. If you’re getting near to the tread wear markers and you see cracking on a tyre, this is not a good sign. You might well notice some deformation too if the tyre is old. All this means you could well be losing pressure and grip.
Check your tyres regularly and if you notice any of the above, consider a replacement. You may not be able to afford a set of winter and summer tyres, but technology has come a long way. You can get all weather tyres which will be an excellent replacement to old and worn rubber.
Remember, the four contact patches that keep your car on the road are the things that ensure you accelerate, brake and turn as you should, so anything that is undue in their condition will cause you problems and potentially cost you your life (and that of anyone else travelling in your vehicle). Stay safe and keep your tyres in tip top condition.
Good advice. I bought a handy little tyre pressure and depth monitor that I keep in my car so I can regularly check them. It only cost about £6 from Amazon.