Tyre wear, miles per set of tyres, wear due to worn suspension...

[WesBrooks]

Hi All,

 

Weird first post here as I'm trying to carry on a conversation that had developed from an original post about wheel bolts being over torqued. I think as I'd led it a way off course from the original post it'd be better in a new thread to help people searching the forum for information in the future.

 

So recap...

 

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My tyres seem to wear out most on the left hand shoulders of the front tyres. I think this is from driving economically ;-) and dropping little speed for clear roundabouts. This isn't the same as the outer edge of the normal tread wearing from low pressure. On that subject I've noticed the inner part of my tyres are wearing most at the front (aside from the shoulders). This would indicate overpressure, but I regualrly check them. 2.1 bar in the front, 2.3 in the rear. Is this indicative of a large proportion of my miles being motorway?

 

My Wife's Yaris acually has tyre rotation (every 5000 miles!) down in the users service guide manual. I've asked my garage to do it a few times but they chose not to each time so far. Hense me doing it!

 

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Your tyre pressures look low to me, just my opinion. Also, why have the rear tyre pressure higher? Unless you are always running around with lots or weight.

Tyre pressures are as per the pressure guide in on the inside of the fuel filler flap. I did find this weird to begin with too as the previous car I had recomended more pressure at the front. This could be done by Skoda to balance the charateristics of the car in a slide and maybe to reduce understeer by letting the front grip more.

Higher pressures are given for a fully loaded car but that would increase the tyre wear in the centre of the tyre exagerating the pattern I've spotted.

Looking at the following I think I'll see if it settles with the new shocks, springs, and suspension mounts - which were already on the cards.

http://www.procarcare.com/includes/content/resourcecenter/encyclopedia/ch25/25readtirewear.html

So I'm wondering about...

~ Do the latest Mk2s with the 18" alloys still have the same tyre pressure recomendations?

~ I've got continental SportContact 5 and they're around 3-4mm and I've done about 35,000 miles. Is that about normal with one rotation or coule I be hoping for more like 40-50k?

~ Is the left hand shoulder wear with even wear across the flat of the tyre just hoofing it around courners or is there a chance this will improve with new suspension mounts/shocks/springs?

~ While a really knackered shocker will cause a wheel to bounce and wear really quickly does the shockers slow degredation also slowly increase the tyre wear rate?

Edited 27 July, 2015 by WesBrooks

[WesBrooks]

Just found another tyre thread which is a good reference for tyre wear:

http://www.briskoda.net/forums/topic/352779-time-for-some-tyres/?hl=%2Btyre+%2Bwear#entry4232015

[Superb170]

35,000 miles - is that on 18" wheels??  I'm going for my third set and I've only 60,000 kms (yes kms not miles!!) done.  Even on 17s, you're doing very well with that sort of mileage 

[Juhagpl]

Continental wears much much faster than the others. Especially if you run fast corners or curves frequently.

From tapatalk

[WesBrooks]

I'd seen things online saying you should aim for between 30 and 60k miles which I though was very optimistic!

 

On the 18" wheels yes. Continental Sport Contact 5 XL. There where two very similar on sale on the Kwikfit website, I got the one with better economy and wet weather ratings. Running about £95 a corner which I was happy with. Wonder what the imminent SportContact 6 are going to be like? Hoping these will last until I can put winters on, in which case the 6s should have dropped a little in price from their August release.

 

While I do test it from time to time on corners and roundabouts my commute and most of my driving is tyre friendly. 45 miles each way with 27 of those on the motorway, mostly free flowing. Longer personal trips to family, Cornwall, the Lakes, and Glasgow are all mostly motorway. Tend to stick cruise on about 65-67ish as while it's free flowing trying to run on the limit is tiring in north west M6/M65/M66 traffic! Usually get 600-650 miles from 48-55 litre brim to brim fills.

 

I'll move to 5000k wheel rotations on the next set and see if I can get them to last longer!

[silver1011]

The longer the tyres spend on the rear wheels the longer they will last.

 

From what I've read over the years front tyres (when left on the front) tend to last anywhere from 15,000 to 25,000 miles.

 

In my experience rear tyres (when left on the rear) often require replacement due to deterioration through age (cracks etc.) rather than from reaching the wear bars.

[WesBrooks]

Ok. New set of tyres going on this afternoon after completeing the suspension service of shocks, springs, front shock mounts, bump stops, dust covers, and rear spring seats (currently on 195k miles on the clock).

 

Old tyres had around 3.5 on the rear but where below 2.0 on the centres and outer edges on the front. Tyre wear was bizzarre. Far outside shoulder wear from hard cornering, but the road surface side had a wear pattern that you'd expect from over inflation - the very central band was low on thread.

 

Total mileage on this set by the time they are changed: 38,200

[silver1011]

Did you have to rotate the tyres to get to 38,200 miles?

 

I would be extremely happy with that sort of mileage out of a set of front tyres, regardless of brand, and still happy enough if that was on the rears.

 

I've never really seen the point of rotating tyres, it just means you have the expense of having to buy all four tyres at once.

 

I guess the advantages are that it saves time with the number of visits to the tyre fitters and the option of being able to negotiate more of a discount off buying four instead of only a pair of tyres?

 

Unless you cover very low mileage so that the rear tyres begin to perish rather than actually been worn down?

 

How much was all the work you had done on the suspension? How many tyres would that have bought you?

 

Unusual tyre wear is actually quite common on the Superb, especially the rears, often referred to as sawtoothing.

[WesBrooks]

Rotated the tyres once at 15000 miles. Will rotate at 5000 miles to even out tyre wear next time.

 

The suspension and dynamics of the car would have been designed to have an even level of grip on all corners. Yes, there is a tollerance for tyre wear but I prefer to keep things even as this would give me, the ABS, and stability control systems the best chance of handling the car in critical hit or miss situations. Probably less of an effect in dry weather than wet weather.

 

I'm an engineer! I've seen the weird wear pattern and I was just trying to understand that better and if possible correct for it to get the best out of the next set of tyres. I now understand the extreme outer shoulder wear to be a result of throwing it around the odd corner slowly adding up. It aparrently is a characteristic often seen on heavier cars. The Q7 for example is lucky to see 5000 from a set of tyres!

 

I am using my car as a mile muncher, so driving tends to be constant speed 65ish on motor ways and long stretches of them at that. This is probably why I'm seeing high tyre mileage.

 

I've gone for Bilstien B6 shockers for longevity and performance and fitted the fronts myself (backs defeated me through lack of fancy spring compressor) therefore my spend isn't really relavant here. My original intention of the post was to try and learn if any of the uneven wear was likely to be corrected by the suspension service. I'll find out over the next year!

 

Regardless of the outcome of my next couple of years of motoring it's worth bearing in mind that any amount of consumer level money spent on tyres will not correct for shagged shockers that would have a direct detremental effect on safety through increased braking distances and reduced cornering (particually chicanes) stability.

Edited 11 September, 2015 by WesBrooks

[silver1011]

I am using my car as a mile muncher, so driving tends to be constant speed 65ish on motor ways and long stretches of them at that. This is probably why I'm seeing high tyre mileage.

 

I too spend prolonged periods at higher speeds, a 165 mile / day commute which equates to approx. 30K per year.

 

Although my speeds are perhaps a little higher (70-80mph) I too enjoy reduced tyre wear but would still be happy to see 30,000 miles out of an non-rotated pair of fronts.

 

Either way at close to 200,000 miles the suspension on your car was bound to be well passed it's best which will undoubtedly have had an effect on tyre wear.

 

If new suspension will improve the driving experience, ride comfort and contribute to safer handling and improved fuel economy then that makes the decision a no-brainer, if however it was purely to eek out a few more miles from a set of tyres then that is why I was curious behind the reasoning.

 

It was interesting to read in your post in another tyre thread how the new shocks had made a noticeable improvement to the way the car handles under braking and acceleration. That alone would make it worth while for me.

 

I'm currently on 80,000 miles but very much hope to see well above 200,000 miles. I think you have one of the higher mileage Superb's on here so I'd be interested to hear what significant costs you have incurred to get to the mileage you are at...

[WesBrooks]

You got me beat there! I used to do 110 mile/day St Helens to Stone in Staffordshire but now it's 90 ish St Helens to Ramsbottom (the long way via preston to avoid the M60 & 62!)

 

So far (hoping not to hex anything) it's been reasonably good. Turbo actuator before 150k, Head lights (150 odd a side - perhaps 100 if on ebay etc) went around 170k. Cruise control stick failed around 150k (think that was 300 ish) and O2 sensor around 180k (think that was about 100 from eurocar parts and I fitted it). Cam belt and water pump service as per usual at 115k and I'll have to do that again in 2017. Thinking I'll probably get the compression checked then to ensure its not nearly dead before spending the money!

 

I did do a thread askign for big ticket expenses to try and get a feel for my likely hood of reaching 250-300k. Ideally want the new generation of Superbs to be at least 3 years old before swapping this one. Hispec greenline estate would save me about £700-1000 per year, but depreciation would leave me out of pocket in comparison.

[WesBrooks]

Here we are:

 

http://www.briskoda.net/forums/topic/363496-pending-high-mileage-big-ticket-expenses/

 

Trust the mileage on that post rather than my dodgy memory dumps in the last post!

 

Bilstiens were about £550 for the set. Sachs Springs and SKF mounts were about £205, fittings and spring seats from Skoda Parts was about £60. Got a garage to assemble the front struts for me £90 and the rears were £100 to fit. In retrospect knowing I couldn't fit the rears I would have got the garage to do the lot. Another case of specialised one-job tools make it soo much easier.

 

For me the decision to do the suspension was confirmed after taking a ride in a friends new (well, 18,000 on the clock is still show room to me! :-D ) Skoda Octavia. The ride was much tighter for lack of a better description. I guess OEM shockers would be more like £200-300.

Edited 11 September, 2015 by WesBrooks

[silver1011]

Ah, I'd seen that thread, I also see that I'd mentioned that I'd follow it with interest, which I will continue to do 

 

I know Coops has a Superb which I also believe is showing some relatively impressive mileage. His has also been pretty reliable so I'm hoping mine turns out to be a good as both of yours!

[WesBrooks]

He he! I hadn't been playing that much attention. I'll update it at some point.

 

On the tyre front I'm wondering if the big alloys and low profiles are purely an aesthetic choice. Seen you commenting on another current thread where the OP has got over 30,000 on 205-55-R16. Wonder if the the superbs, the Q7 and the like would last better on tyres with a taller profile that could flex a little to keep the main tread on the ground. After all F1 are on tall profiles, is this through rules or performance? Likewise the greenlines and most eco cars are on taller tyres too.

[psycholist]

Big alloys may offer more grip because the tyres on them tend to be wider for the same overall tyre diameter, but they more than likely are the same for the same width tyre - or worse if the road surface is bumpy.

 

High profile tyres give lower rolling resistance, a smoother, quieter ride, less chance of damage from bad road surfaces and cheaper replacement tyres. In terms of handling, don't confuse a crashy ride and being able to feel all the bumps with having more grip or better cornering performance either, one mostly doesn't guarantee the other. Also at legal speeds the Superb is nowhere near it's handling limits no matter what profile tyre is on it once it's a decent tyre.

 

Alloy wheels were originally brought in to give the car's wheels less inertia to follow the bumps better and maintain grip (Reducing unsprung weight), but modern alloys, especially the big diameter ones, are often heavier than steel wheels so the look is about all low profile wheels/tyres offer.

 

I can't run less than 16" wheels to clear the brake disks on the CR170 though. My winters are 16" and summer are 17", and there's not a noticeable difference in ride between them.