It is always good to hear from our customers and
on behalf of Bridgestone South Africa I would like to thank you for taking the time and effort of sending us the mail and we wish you many more happy miles on your Firestone tyres!
The treadwear, traction and temperature markings you refer to actually have no relevance in South Africa. In fact they don't have any relevance outside of the United States. Sometime back, someone in the States decided that they needed a point of reference and comparison, between tyres available there as far as traction, wear, and heat dissipation goes. They then proceeded to set up a controlled test capable of measuring these three factors. Then, because of the size of American market, tyre manufacturers decided to include this information on all their tyres which could end up in the States.
The point is that the figures are only accurate when used on the same surface as the test was conducted on, at the same speed, carrying the same load, and in the identical ambient and environmental conditions as the test situation. Where the 400 in your case suggests that your tyres will give better tread wear than those of your friend's under test conditions, in local conditions the reverse may be true. We would expect that the trend, would in fact, be similar, but to differing levels, but they could be totally different. They are also very vague about the value of the measuring units, so one cannot assume that your tyres will have 3 and a bit times better tread wear than your friends, but the higher number does mean better.
You are correct in that there are dealers who are either insufficiently trained, or ill equipped to handle this sort of complaint satisfactorily. In our dealer family organisation we are currently addressing this problem by instituting a very concentrated training program around the country. Unfortunately this is quite time consuming due to the amount of dealers involved, which means it is not happening at the speed we want, but a more concerning problem is that once properly trained, the staff are being hunted by the rest of the industry, and we have to start again.
The problem you have is not a common one, but here and there an out of spec tyre does get through the system. I would be very surprised though if all four are out of round. The other concern that I have is that some other problem could have caused the tyres to wear out of round, and this is not as uncommon as one would like to believe.
I know you are most probably sick and tired of having your tyres looked at, but I'm sure you will understand that I cannot take a warranty decision without our having inspected the tyres. Please let me know where you are based so that I can arrange to have one of my field engineers contact you, or if you are close to Isando the best would be to bring the car to our TEC (technical examination centre) and we can sort things out for you.
Tyres should be rotated generally at 10 000 kilometer intervals. This varies slightly from car to car and with some circumstances, but is a good rule of thumb. There is no specific time for balancing tyres and many tyres only get balanced once during their life time. However, there are times when rotating can show up an imbalance or some other cause may require the tyres to be re-balanced. They will tell you soon enough with either a steering shudder (fronts out of balance) or a vibration through the seat (rears out of balance).
Your cars hand-book should give you the correct inflations, or there should be a sticker in the drivers door, or at the fuel filler. In the absence of any of these I would use 200 kPa all round for normal driving and increase to 250-260 kPa rears and 220-230 kPa fronts when fully loaded.
By the way, also remember to have your wheel alignment checked (around every 30 000 ks or after a pothole rough roads). This can help get the most out of your tyres.