# Calling Mr Tips...



## ESL (Jan 27, 2004)

Here's deal and I'm hoping someone can can clarify for me (PG perhaps...?)

Managed to drive over a brick yesterday in my Audi, fitted with low profile Dunlop SP Sportmax tyres on. The brand is not not really significant but they are "directional". Caused a bit of damage, in that there was a small sidewall bulge on one front tyre. So took it to that place where the fitters are quite speedy, for them to fit a new one.

This is where it gets interesting - It's a leased motor and it seems the leasing company do deals with tyre manufacturers to get the best deal. Well the deal of the day/week/month/year seems to be with Bridgestone, so that's all the fitter gets authorised to fit.

So now I'm left with a decision to have one OE fit Dunlop directional on one front wheel and one Bridgestone non-directional on the other front wheel.

SO - IS THIS A PROBLEM?

Me and the rather fast fitter thought it was not ideal at all, so we contrived to closely inspect the other front tyre, and bugger me, if it did not turn out to have damage too h34r: , so we changed that one as well to ensure we now had two new Bridgestone non-directionals on the front, with the two OE Dunlops on the back.

Not quite "kosher" I know, but does it all really matter? I have always thought that you should not mix tyre brands on the same axle, and should not mix directional tyres on the same axles as well, cos on modern cars the ECU can/might be affected, especially if ESP is fitted.

But do any "specialists" out there know any different?

:huh:


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## Boxbrownie (Aug 11, 2005)

:lol: Your as crooked as me matey....before I got to the end of your little story I had already decided it would be better to have "damaged both" rather than replace just the one.....bloomin' good job to.....in answer to your question, no it is NOT a good idea to have a directional and non directional on the same axle......not even a great idea to have different makes front and back although millions do.....can get a bit hairy in the wet but more especially with RWD vehicles like BMW & MERC.

You did the right thing and the fitter (if it was purely on safety rather than monetry reasons) should be congratulated, too often nowadays spanner monkeys (not Paul of course! :lol: ) couldn't give a toss as long as they can get back to texting thier latest willy warmer! :tongue2:

I reckon those rear tyres will need replacing in thousand miles or so......won't they?


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## KEITHT (Dec 2, 2007)

Don't know the technical reasons for not mixing types, but i am sure that you shouldn't mix directional with bi-directional on the same axle...

Me..i am slightly anal...i like all 4 tyres the same...stems from having a really bad handling MG Midget....everything seemed fine with the chassis and suspension...but it did have 4 different tyre.....a switch to 4 decent goodyears transformed the car....

Only downside is when tyres get discontinued.....its gutting when you have to put 4 new ones on when you only need a couple...

Keith


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## ESL (Jan 27, 2004)

Boxbrownie said:


> I reckon those rear tyres will need replacing in thousand miles or so......won't they?


s'funny you mention that, I noticed on the drive home a slight imbalance on the rears...

h34r:

Keith - I would have preferred all 4 as well, no good reason other than your's :lol:

Still...


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## pg tips (May 16, 2003)

Do you want the "always watch a botch" answer or the "technically correct" answer or the one somewhere in the middle h34r: :lol:

You did the right thing mate.

Mix and match ain't much of a problem of the family 1.1 pop but if you are in the habit of driving above 50 then matched axle pairs is always the way to go.

BTW if you only have 2 new tyres fitted it's recommended to put the new ones on the rear (even on FWD's) as it gives you more grip in a rear end slide (not that you'd ever be driving like Kimi I'm sure).


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## ESL (Jan 27, 2004)

Cheers PG mate.

Interesting take on the "put the new ones on the back". Makes sense. 

Looked up the tech spec on both tyre makes and they are both classed as high perf, low profile tyres, so other than the fact that the Dunlops had a directional tread, there was not much in it. I noticed that my spare was a full size directional as well, so in reality, it would only be suitable on 50% of the wheels in case of a blowout. :blink: I have heard it said, that if you have to fit one on the "wrong" side, it should be treated as a "get you home measure" as the wet weather performance is compromised, and to have it swapped round ASAP. Basically - treat it as a space saver then.

I do a good bit of motorway driving and as it's almost permanantly pissing down these days, thought it best that they were at least matched on the same axle.

If there are any tyre ANALysts out there, these are the bits of rubber in question:

OE = Dunlop SP Sport Maxx

Reps = Bridgestone Potenza


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## pg tips (May 16, 2003)

yeah right call on your spare, if it goes on the wrong side then 50 MPH max and get it sorted as soon as.

At least you have a spare, so many cars these days have a can of glue!


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## michaelh (Oct 1, 2007)

I did the same. Drove over a brick. Cost me Â£250 for a new alloy wheel. I hadnt had the car long anyway. Only about a year form new. :furious:


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## Guest (Sep 8, 2008)

The law in France is that tyres on the same axle must match, It's a MOT failure, or a fine if you get pulled by the gendarmes.

It's a right pain if you've got something fairly obscure fitted, for instance AVON !

Tyres are also ridiculously expensive over here.


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## ESL (Jan 27, 2004)

You sure about that? :huh: Seems a bit harsh, but if you say so...

The UK law is similar in that it's illegal to fit tyres of different construction - i.e. radial and crossply, but not manufacturer. But mixing brands or patterns is OK legally - maybe not technically - maybe to the detriment of performance characteristics, but OK legally.


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## Boxbrownie (Aug 11, 2005)

The time you will notice a difference is exactly the time you don't want to....emergency braking wet or dry....you'd be suprised how different the friction coeffecient is on good/bad tryes....let alone worn/new!

The Potenzas are "usually" an excellent tyre.....depends which type......if its a low profile euro market Potty then it'll be very good....some of the Japanese Potenzas designed for small town cars are just quiet and last forever but not much grip, but then of course pottering around in Tokyo at 25mph requires little grip! :lol:


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## ESL (Jan 27, 2004)

No - it's the full "caffeine" Euro low profile 18inch Potenza so it should be a good bit of rubber. 

My only issue is that the bloody leasing company seem to think they know better than the car manufacturer about what tyres will be OK, and pay no real heed to to the fact they may be compromising the handling characteristics by mixing rubber on the same axles.

I must admit, I'm no Lewis Hamilton, so I'm unlikely to notice any performance difference in general use - but it's the "Oh ****" moments I'm talking about.

Like you said - that's exactly the time you will find out if everything is working OK or not!


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## ESL (Jan 27, 2004)

Interesting reply from Dunlop's Tehnical support office:



> "According to the law in the UK it is permissible to mix tyres across the axle as long as they are of the same construction i.e. radial.
> 
> Goodyear Dunlop, many of our competitors, and many motoring organisations however take this further and recommend tyres of the same construction and pattern should be matched across the axle, so aiding equal handling especially in the event of extreme driving conditions. By this we include harsh braking. In some countries, such as France, mixing tyre brands across the axle is illegal.
> 
> ...


Confirms the French legal view too.


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## Guest (Sep 9, 2008)

Tyre laws seem to differ across Europe.

When we lived in Germany I had a slow puncture in a V rated tyre, the German garages refused outright to repair it. My German language skills were not good enough to enquire if this was down to the law, safe practice or possibly due to the speeds drivers get up to on the unrestricted parts of the autobahns.

A quick hop over the border to Holland and it was repaired with no problems.


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## michaelh (Oct 1, 2007)

I personally wouldnâ€™t put two different types of tyre on the same axel. I tend to just get the same brand that was originally on the car. In my Saab's case Conti's. You need to shop around though. I got a garage to price match a continental tyre price that i saw on the internet. Some will be willing to do this for the business.


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## strange_too (Feb 19, 2007)

I'd only run the same brand and tread on an axle and preferable the same on all corners.

I only drive on Michelin Pilot Sport at the moment. I find the grip levels with Conti's too low, creates understeer. Goodyears & Dunlops seem to give me poor grip in the wet. However it's all to do with your driving style.


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## Guest (Sep 9, 2008)

In accordance with French law, I've got Conti's on the front of my V40, and Bridgestones on the rear.

My Scimitars are matched all round - Dunlops on the 5, and Kumhos on the 5a, curiously though, classic cars don't have to have matching tyres in France.................. and only have to have an MOT (CT) every 5 years, so if you see a classic behind you in france get out of its way.

Modern cars have an MOT every 2 years. Believe it or not, but I actually prefer an annual MOT.


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## rhaythorne (Jan 12, 2004)

Funny you should mention this George. I had similar experiences very recently trying to replace the Dunlop Sport Maxx tyres on my Megane after a couple of punctures.

My tyres are 235/40 R18. After the first puncture I was able to get what I think is basically the same tyre but an "extra load" version, though not identical to the original. After the second puncture I was offered a Bridgestone alternative (at a whopping Â£260) but "the boys to trust" did a local search and came up with a similar Sport Maxx tyre but this one is a "TT" version. It has an "outside" but no arrow mark to denote the direction of rotation so maybe it's not directional like the other three :huh: Anyway, I've now got three slightly different types of tyre on my car. Oh, and I had a third puncture some time ago that was repaired so that one's of questionable quality.

It might not matter too much driving around town at relatively slow speeds but I'll probably be doing another track day soon and I'd much rather have four tyres all the same when I'm braking into Paddock Hill Bend, if you know what I mean. Fear of the unknown!

The prospect of spending Â£700-Â£1000 on four new tyres doesn't appeal


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## ESL (Jan 27, 2004)

All I know about asymmetrics is that they have an "inside" pattern and an "outside" pattern, So when fitted to a vehicle, all the outside patterns must be the same. I think which side is "outside" should be marked on the sidewall. I think you can get asymmetrics which are also directional, in which case they would have the directional arrow as well.

I read somewhere that with asymmetrics on a high performance car (especially where used in high performance situations) all 4 should be changed at the same time, otherwise handling could get "unpredictable".  Sounds expensive...


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## mel (Dec 6, 2006)

One of my Pajero's had a tyre nicked off the rear carrier and I wasn't able to get an exact replacement for the Japanese OEM tyre - the "jumping about boys" came up with a relatively reasonable cost replacement which looked substantially the same, and had pretty well all the same marking but was a different breed of tyre, all fine! :yes:

Till the day I had a flat and changed it (and that's not easy on a forby either, needs two of you to lift the bloody thing off the rear carrier), don't know how anyone managed to nick it in the first place.









That car was an absolute pig's ear with that one unmatched tyre on the front, it just wasn't comfy to drive, felt like it was going to fall off the planet anytime, that was in 2wd or 4wd. Got the flat fixed and the kwik guys to swap it back on, and all was well again - so it's not just hi-perf machines that don't like mixed tyres









If there was to be a motor you would think wasn't going to notice a thing like an odd tyre, you would assume it would be a working forby that tackles rough stuff in it's stride, eh?


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## Marky (Sep 29, 2005)

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