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MG MGA - Tyre age question / survey
As some of you may know, based on past threads, I am an engineer with Bridgestone tyres in Europe. We have been recently discussing on tyre age and its effects on performance which has also been a topic here on a number of occasions. I would therefore like to ask if you would mind to give me the following information regarding the tyres currently mounted on your cars:- 1) DOT week and year - This is the last section of the DOT code marked on the sidewall. You will find it marked "DOT" then a series of numbers and letters, the last 3 or 4 are the week and year. Prior to 2000 this was 3 figures, after 2000 it changed to 4. 2) Performance in the wet - As this is the most affected by aging I would appreciate an honest answer as to whether you get wheelspin, understeer, oversteer skid under braking. We, along with many other tyre companies, recommend a maximum of 10 years before tyres should be replaced for newer ones. I am however asking for technical/safety reasons rather than commercial ones so any information you give is greatly appreciated. While you are crawling round to find the DOT be sure to check your tread depths and pressures to make sure you are safe on those points also?!! Many thanks for your help, I will add my own tyres as an example in the next post. Neil |
Neil Purves |
1) 346 (week 34 1996) 2) In the wet. Wheelspin under medium acceleration from standstill, tail breaks out easily when accelerating in the corner, braking must be controlled not to cause skidding. In dry all is okay. Best regards Neil |
Neil Purves |
Neil, this strikes me as a bit odd. Your say that tires should be replaced after a maximum of 10 years, yet you are using 11 year old tires. ??? Until just recently, I was driving on tires dated 105 (March '95). I don't normally drive much in the rain if I can help it so I can't tell you how well they performed in the wet. New tires are dated 1407. |
Andy Bounsall |
Neil Do want the make of tyre as well, or is that unimportant? Steve |
Steve Gyles |
Hi 1 Goodyear NCT 5102 2 These tyres will spin on pulling away in the wet but you would have to drive like a lunatic to make them break away when cornering on mormal roads wet or dry. I have driven 2 wet sprints on these and wheelspin is hard to control when leaving the start line, cornering depends on the surface, one sprint the grip was brilliant but at Silverstone the track was slippery so there is no conclusive answere. They will skid in the wet like most tyres when braking. All 'A's oversteer when pushed wet or dry. Terry |
Terry Drinkwater |
Hi Neil, Mine are older than I thought as the car was restored in '96 I assumed the tyes were new then . - my tyres are Continental 165 15 with DOT code 053. made in Germany ( written in French) as the car is of Swiss origin. Seems like I should be changing them sometime soon even though plenty of tread. I have only used the car in the wet a couple of times and not had any skidding /spinning/slipping but they do squeal accelerating from rest when turning in the dry. cheers Cam |
Cam Cunningham |
Hello Neil, Very interesting. My tyres are Marshall Steel Belt Radial 771. Size 165 R15 86T. DOT H2TB YA1Y 123. I presume this translates into week 12 1993 ? This figures as the car was restored in 1993/4 after returning to uk from US. I have used the car on a couple of trakdays at Donington Park in the dry and I also drive the car pretty hard on country roads in the dry and have never (yet touch wood) had any moments (in the dry). I don't choose to go out in the rain but have been caught out in it on several occasions. I know that the tail will wag in the wet in second gear when coming off a roundabout, but I have never tried to spin the wheels deliberately or pushed the car in the wet. However on Tuesday this week I had one huge adrenalin filled moment when driving on winding roads when there had been odd showers of rain with stretches of bone dry road in between the wet patches. In third gear coming out of a right hand corner which I know is slightly off camber the car snapped through 90 degrees and headed across to the other side of the road. Fortunately there was nothing coming in the other direction. I was almost certain I had had a puncture or lost a wheel it was so violent.(Not having used the car for two or three weeks I had checked the pressures before setting off). Needless to say all four wheels were there ok and plenty of tread but the road was slightly damp. Your comments have convinced me about the wet performance of old tyres. New tyres for me! Any recommendations ? David |
D C GRAHAME |
Pirelli 6000 for me, DOT last figures 046,runs fine wet or dry. Dirk/Antwerp |
D. Van Ussel |
Hankook 286 (July 1996). Stuck like glue so far. Terry Drinkwater's Goodyears did not stop him rolling into me, so better than his!! Steve |
Steve Gyles |
hi mine appear to date from 98 and are firestone and if it ever got used in the wet i could tell you how they performed, they are fine in the dry but it doesn't go very far or fast gordon |
g c pugh |
Neil - As a result of the information you passed onto me - Firestone/First Stop/ Ibiza Spain, have sourced and served me the five Firestone tyres I originally reguested and was told no longer existed. Many thanks Brian Pollard |
Brian Pollard |
Neil DOT code 4905, Firestones. Prior to 2005 I had Kelly radials from circa 1990 which had become quite treacherous even though they had plenty of tread. The Firestones transformed things. They behave normally with little wheel spin but they do sometimes lock up on wet roads David |
David Marklew |
Ho Ho Ho! I can't believe Steve is bringing up the old Le Mans chestnut again, it was his fault for stopping at a red light and I was reading a map at the time Terry |
Terry Drinkwater |
Michelin XZX DOT 096 (1996) Made in France. Not much grip off the line in a hill climb but fine on the road, wet or dry due to in built speed limiter (wife). Regards Mike |
Mike Ellsmore |
Michelin XZX from about 1990. Pretty good in the dry with predictable breakaway. More slippery in the wet, of course (same as you describe Neil), but still predictable. Maybe we need to get together and compare some cars/tyres to know if there is any big difference. After the previous thread I planned to change tyres, but didn't get round to it yet and I can feel it slipping down my priority list! I have changed a couple of inner tubes, they definitely also deteriorate with age! I have 4 old Firestone tyres (unused from the 80's I think) and haven't decided what to do with them yet. This is an interesting thread! Neil M |
Neil McGurk |
Will somebody with Michelin XZX tires post a photo of the date code location? Mine show NO "DOT" codes on the outer face of the tires. I looked at all 4. These were purchased in, or around, 1996. They seem to be performing OK. but now I am a little worried since I can't find the mfg date. They do have what appears to be lot codes as follows: 1 reads DG482 2 read DF521 1 reads CZ1265 All 4 "codes" are followed by numbers in a different field: 20-1554 None are preceded by the letters "DOT" and the last one doesn't fit the pattern for date codes already listed. Thanks, Chuck |
Chuck Schaefer |
Chuck, check the inner side of the tire (the pointed toward the the car. My old tires were mounted that way making me originally suspect that they didn't have a DOT code. I read somewhere that all auto tires made sine the late 60's have a DOT code. |
Andy Bounsall |
Neil, As an engineer for Bridgestone tires what is your opinion on siping tires? They (the regional tire chain) claim it allows shorter stops on wet surfaces,it also extends the mileage because the tire runs cooler and lastly it reduces the amount of road noise generated by the tire. Ray |
Ray Ammeter |
Thanks for all your responses so far, I am now going to do a little bit of analysis at our test track with my old set of tyres (unfortunately not on my MGA as the track is outside Rome) and see what the measured difference is between the old ones and a brand new set. I will let you know the results. As I use my car as an almost daily driver I have seen a marked drop in wet performance over the years. I will replace them in the next week or 2. Also I should say that the tyres are in excellent condition as (apart from when actually driving) the car is always in a garage, either at home or at work. No cracks etc. If I didn't know better I would think the tyres where only a couple of years old. Ray - Siping gives extra edge elements which can improve wet braking as well as traction. It is used a lot in Scandinavia where they need extra winter performance but dont need a studded tyre. There is a small reduction in dry performance which I think would not be felt on an MGA, and the siping can mean some tearing on the block edge when it is close to the sipe. I am not a US expert but I believe it is quite popular in the northern states and Canada? I saw once a machine manufacturer from the US at an exhibition and I would say the claims he made where a bit exaggerated but certainly the improved grip is true. Neil |
Neil Purves |
Michelin XZX tyres DOT 289 / 299 (no little triangle so that's 1989). Very good in the dry, a little tail happy if I push it in the wet. I've had plenty of experience of that in the last few weeks! Chuck, the DOT code is only on one side of the tyre (roughly under the large XZX writing). Three of mine were on the outside the other two had it on the inside - counting the spare that is) dan |
Dan Smithers |
This thread was discussed between 26/07/2007 and 31/07/2007
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