Firstly it would be appropriate for me to explain what a part worn tyre is. A part worn tyre is a tyre that has been previously fitted and removed from another vehicle. It could have been removed for a number of reasons; the vehicle could have been scrapped and the tyres removed, another reason would be that the tyre has reached the legal tread depth limit in a country with a different limit to that of the UK. This is the most common source of part worn tyres. As an example the legal tread depth limit in Germany is 3mm (UK is 1.6mm), when the tyre is removed in Germany it will be transported to the UK and sold as a part worn tyre, with 1.4mm of 'useable' tread left.
Now I could approach this topic in one of 2 ways. The first being that part worn tyres are dangerous, damaged, past their 'best before date', or poorly fitted. However for a number of reasons I won't. Not all part worn tyres are bad and there are a number of suppliers who are very good at what they do. You could argue that the tyres on my car are part worn, and I would agree. I do however know the history and age of the tyres on my car.
What I will do is demonstrate that it is more cost effective to fit a brand new tyre than it is to fit a part worn. I have used a very common size; 195/65/15 and have used the following information:
SAVA Intensa HP - £58.96 fitted – 8.3mm of new tread less the 1.6mm legal limit leaves 6.7mm of useable tread.
Part worn tyre - £15 fitted – 3mm of ‘new’ tread less the 1.6mm legal limit leaves 1.4mm of useable tread.
From this information we can calculate that you would need 4.8 part worn tyres to match the amount of tread on a new tyre. At £15 per part worn, this means that it would cost £71.79 in part worn tyres to get the same amount of tread as a new tyre! This is for every tyre and it doesn’t include the inconvenience factor of return visits to the part worn dealer every time the tyre needs changing.
Mission accomplished! New tyres are cheaper than part worns, fact! I have used a mid range tyre, but you could actually use the same calculations and buy a premium brand tyre cheaper than a part worn. It's also worth noting that tyre performance drops of at around 3 mm. Braking distances increase, etc. If you use part worns you will never have a tyre performing at its best.
It’s your call, your money, your safety so it would be wrong of me to tell you not to purchase part worn tyres. What I would say is ‘do your research’ and carry out the checks as described above. The best option is always a new tyre that has been designed for your car, you will find the recommendation in the owners manual.
If you choose to fit part worn tyres please ensure that you check the following:
1. Check the tyre for any cuts or bulges. Both would suggest damage to the internal structure of the tyre.
2. Check the tread way around the whole circumference of the tyre. The minimum (i.e. 100% worn) tread depth a part worn tyre can be sold with is 2mm across the FULL width of the tread and around the whole circumference.
3. Make sure the size and speed rating of the replacement tyre are suitable for the vehicle. Cross axle sizes must be the same and all speed ratings should be adequate for the vehicle.
4. Ensure all puncture repairs are in accordance with the British Standard (BS AU 159)
5. If your tyre has the words 'direction', 'rotation', or 'outside' written on it, it must be fitted accordingly.
6. All part worn tyres must be labelled as such. They must have the words 'PART WORN' marked in capital letters. This must be permanent and legible. (I think this is to give other road users the chance to get out of the way! (Sorry, I said I wouldn't))
Some people will disagree with everything I have just said! But please leave a comment and we can explore your thoughts.
All the best
Stuart