Are half my tyres fitted the wrong way round??

[CrispinF]

Hi, first post from noob seven owner! 

I have Avon ZV3 tyres, and something's been niggling me about the asymmetric tread pattern... it looks correct for the right-hand and wrong for the left-hand wheels. 

Here's a photo, when the car was in showroom on a different plate... anyone see what I mean??

On the left-hand wheels it looks to me like the pattern will push any water the wrong way (from the inside of the tyre towards the outside) including up dead-end channels. On the RHS it looks like water will be pushed inwards nicely with no blockages.

However, every tyre has the "Exterior" marking on the outside.

Do these tyres come in R & L versions? I cannot find anything online to suggest they can be bought for L or R side, and cannot find any marking on the tyre itself.  

Or is the "Exterior"/"Interior" marking simply wrong for one side of the car, and the tyres on the left side are supposed to be fitted the other way around?

Here's a more detailed view of the tread

http://lovetyres.com/public/tyre/Avon-ZV3.jpeg

Grateful for any wise words!?

 

[nickh7]

They are usual marked with a rotation arrow if they should be fitted in a certain direction 

[Jonathan Kay]

As you've spotted they're asymmetric...but TTBOMK they're only made one way round.

Or is the "Exterior"/"Interior" marking simply wrong for one side of the car, and the tyres on the left side are supposed to be fitted the other way around?

I'd put the "Exterior" on the outside.

Jonathan

PS: Yes, it does look weird, see also A021Rs.

[Golf Juliet Tango]

Lots of modern tyres are designed for inside/outside rather that rotational fitting.

[paul richards]

Looking at your picture I think your tyres are fitted correctly. 

[CrispinF]

Thanks for thoughts.

If they are fitted correctly (and the fact that the "Exterior" labels are on the outsides suggests nobody's done anything daft!), this can only mean that the narrow diagonal grooves are unscientific "roughness" rather than meaningful water conduits. Or maybe it's so that the left side of the car will have exceptional grip when reversing really fast;-)

I'd love to hear an explanation/analysis from a tyre designer!?

[Golf Juliet Tango]

Have you looked at the manufacturer's website?

[SLR No.77]

Don't underestimate how much of the tyre design is purely for aesthetics, the asymmetric pattern reinforces the perception that the tyre must be able to perform well, even better than a symmetrical tread pattern ... it's good marketing.

[StevehS3]

They are fitted the same way as mine before I swapped them out. Go easy on them, there isn’t much grip.

[Roadsport06]

What age are the tyres? They may need changing anyway

[CrispinF]

Thanks all.

The tyres are almost new. I might look into changing them anyway, as this undermines my confidence!

Manufacturer's website... well they no longer make this particular model. About asymmetrical tread patterns in general, they say this http://www.avon-tyres.co.uk/car/tread-patterns :

An asymmetric tread pattern has a different pattern on the inside part of the tyre compared to the outside part to help improve dry grip and water dispersal. Larger tread ribs/blocks are on the outer side of the tyre, this is to improve cornering stability and grip on dry roads by offering greater contact area. This also reduces tread squirm and heat buildup on the outside shoulder. The inboard side of the tyre will feature smaller tread blocks to aid water dispersal and improve wet grip. Specific tyre to rim mounting required - a tyre with an asymmetric tread pattern can be fitted on all four positions of a car but must be orientated correctly with regard to the inner and outer facing parts of the tyre. 

So my conclusion is the tyres are fitted correctly, and either

a) the precise pattern of all the diagonal grooves is irrelevant, and they have no role in water channelling, or

b) the pattern does matter, in which case my RH tyres will behave better than my LH in the wet (when driving forwards!), and this tyre design is really dumb. Maybe that's why people find it's not got much grip, and why they no longer make them!? This design could only work if they made specific LH and RH tyres, with the diagonal stuff oriented the opposite way.

[Roadsport06]

There's nothing wrong with ZV3 tyres, just they are not designed for such a light car. They're fine on an ordinary tintop.

The rubber just doesn't grip, worse in the wet.

What date were the tyres made? Do you mean nearly new as there is plenty of tread depth left? These tyres would look new after many miles so unless you know the age of them they could be even harder.

 

How to check their age

https://www.continental-tires.com/car/technology/tire-knowledge/lex-1-2

[CrispinF]

Useful - thanks! They are "4111" i.e. made in Autumn 2011. They look brand new!

[StevehS3]

I swapped mine out for Uniroyal RainSport from Camskill which seem noticeably better (for road use) and are reasonably priced. 

[nickh7]

Treat your self to some 888rs orZZRs . They’ll be better than you current boots in the wet and you won’t believe the grip in the dry :-) 

[Ian B]

I'd echo the above, change the ZV3's for another tyre better suited to the 7 - you will be completely amazed at the transformation and increased grip; like a different car 

[SLR No.77]

"An asymmetric tread pattern has a different pattern on the inside part of the tyre compared to the outside part to help improve dry grip and water dispersal. Larger tread ribs/blocks are on the outer side of the tyre, this is to improve cornering stability and grip on dry roads by offering greater contact area. This also reduces tread squirm and heat buildup on the outside shoulder. The inboard side of the tyre will feature smaller tread blocks to aid water dispersal and improve wet grip. Specific tyre to rim mounting required - a tyre with an asymmetric tread pattern can be fitted on all four positions of a car but must be orientated correctly with regard to the inner and outer facing parts of the tyre"

I maintain that the statement from Avon is marketing b******s! The tyre can be run with either the water dispersal grooves oriented the correct way or it can be run with the small/large blocks oriented as they say .... but not both together. It would need a mirror version of the tyre to be available to agree with their marketing statement.

[CrispinF]

Yes that's the conclusion I've reached too. Now looking into some nice alternatives!

[DJ.]

I have Uniroyal Rain Expert 3 tyres on my Seven which I find a lot better than ZV3s. They have a similar pattern which is reversed on each side, and this is what the Uniroyal website says:

 

Is it right that the grooves on one side of the car point upwards and on the other side downwards?

Yes. The long, steep grooves on the outer shoulder of the tyres are designed to direct as much water as possible to the outside via the shortest way and therefore in shortest possible time. The RainSport 3 and RainExpert 3 are designed in such a way that the water can be drained in the direction of the shoulder, to the outside, as well as in direction of the deep circumference grooves. The angle in which they run has no impact on the aquaplaning performance and the driving comfort of the tyre. So it’s completely ok, and doesn’t change anything with the overall performance of the tyre, if the tread pattern seems to have a different orientation on either side of the car.

 

 

 

[CrispinF]

Looking in detail at the tread patterns, this looks believable for the Uniroyals, as in one direction the diagonals will move water to the outside of the tyre and in the other it will move it to the deep groove (as you/they say above). The problem with the ZV3 in this respect is that the tyres on the LHS are apparently directing water up narrowing and/or dead-end channels, and that water then presumably has to get forced out under flat bits and perhaps therefore increase risk of sliding.  

I've seen the Uniroyals report grade "E" for fuel efficiency, which seems pretty poor. Does this make much difference in reality, compared to a "B" which many other tyres claim?

[Golf Juliet Tango]

I only ever look at the ratings for grip.

[DJ.]

For the Seven, I tend to think poor fuel rating is a good sign. It would indicate higher rolling resistance and consequently softer/grippier rubber.

 

As our cars are so light, there isn't as much load on the tyres and the effect on fuel consumption is probably not as noticeable. Having said that, as Stephen says, fuel consumption isn't too important to me.

 

Duncan

[SLR No.77]

There's no way I'd run tyres on the front of a Caterham with grooves that shed water to the outside on one tyre and the inside on the other, standing water can be an issue due to the lack of weight and having a tyre combination that could potentially add a sideways force at the point of starting to aquaplane would be madness. 

[CrispinF]

Does that make Continental Premium Contact 5 a good choice for road use? "E" for economy, "A" for wet grip, and no mad tread patterns! Fitted for £58 from blackcircles. My 7 wants 185/60 R14.

[DJ.]

Give them a go and report back