What Tyre Pressures

[Rory]

If you're prepared to pay the price, then get Michelin Primacy HP's. They'll do everything you're asking for.
There might be a cheaper tyre that's just as good all round, but who knows?
Use Costco for a reference price, but I've found some independants can be just as cheap. Most places (inc Costco) will probably have to order them though.

 

[davidsl500]

Do you park with the wheels on full lock, just so you can see the tread ?

No, of course I dont - half lock is plenty...

 

[jberks]

If you're prepared to pay the price, then get Michelin Primacy HP's. They'll do everything you're asking for.
There might be a cheaper tyre that's just as good all round, but who knows?
Use Costco for a reference price, but I've found some independants can be just as cheap. Most places (inc Costco) will probably have to order them though.

Just rang them - £161.19 each and special order. That's £645 a set!

Rang my normal people, but the chap I knew has left now. They were trying hard to convince me that I should buy the brands as the 'quality' is a big difference. The problem I have is that the Contis are listed by everyone as a hard wearing top tyre and cost £140 each. They spun whenever I floored the pedal and I only got 15k out of a set . Not good when you're doing 25-30k pa.

A local guy has offered me some Nexen's for £73 all in. Now I accept they may be a shade off on handling and a few spots off on wet grip etc, but he rates them and the reviews aren't that bad. Will I actually be able to tell. My Surname is Berks, not Schumaker after all. Assuming they last 75% of the life of the contis, I'm still quids in. I do drive quickly but I'm no racer and I have esp,abs, sports suspension and all the toys anyway. Plus they are 20mm wider than standard fit on the avantgarde anyway which should compensate to some extent. How bad can they be?

Am I being daft here or should I go with the nexens?

Just been through http://www.tyretest.com
The sportcontacts reviews slate the wear characteristcs (finally something I can verify and agree with).
The nexens are rated quite well. Ok grip isn't 1.0 but it's not 2.5 either. Also people with Lexus and Mercs on the same size are saying they would buy again. Actually, based on the reviews I get the impression they would actually outlast both the contis and the bridgestones for a minimal drop in grip. Assuming they end upo gripping like a 225 - what have I lost for my £155?

 

[angus falconer]

re Conti SportContact 2's

on the supercar tour, it was very hot, and the tryes were warm and the gave almost unbelieveable levels of grip. in the car park, they had a full coating of stone all round the tyre circumference. this is what impressed me. I have never seen a road tyre do they before.

What it means is that this tyre is a pure performance tyre..

Well that explains why a lot of 911, M3 and M5 drivers recommended them in the various forums I looked at a couple of years ago when trying to choose a new tyre to prpace the SportContacts my C43 came with.

I obviously didn't get much heat into them and so suffered from low grip, harshness and twitchiness in wet until I went for the Goodyer GSD3's.

Oddly enough, although I have had a lifelong aversion to Michelin tyres (re-inforced when a fleet manager forced some appallingly harsh, twitchy and rubbish-in-the-wet Pilots on my last company car) the Pliot Sports my second C43 came on seem OK.

I still want GSD3's though - as DavidSL500 points out the tread pattern wins every time

 

[Rory]

Assuming they end upo gripping like a 225 - what have I lost for my £155?

Well if they're only going to last 6-9mths, even if they were awful in some respect (which I'm sure they won't be) you'll get through them pretty quickly.

I don't get the bit about them being 20mm wider - are they a wider size, or contructed differently?
Also, all things (ie tyre pressure) being equal, you won't get more tread on the road. If the tyres are wider, then the front to back measurement of the footprint touching the road will be less. You can check a car's weight by measuring the area of tyre touching the ground and multiplying it by the tyre pressure.

 

[jberks]

my point was that they are 245/45/17. Standard fitment on the avantgarde is 225/55/16 so I start with 20mm more tyre on the road than a normal avantgarde, at least in terms of width.

So, if they don't perform as well as a 245 conti (fair enough really) they should still perform as well as a 225 conti which would be in excess of what I need for even my most lunatic moments I suspect.

I accept some of the point that the load is spread over the surface area and therefore less cross width would force more front to back width to make contact in order to give the same lb/sq-in coverage, but there must be a diminishing aspect to this, especially allowing for the fact that the tyre pressures are identical or else why bother with wider tyres at all?

Thats my theory anyway.

 

[Myros]

I thought you got more footprint

by increasing the diameter of the tyre, so that there is less squish for the fore and aft just-clear-of-the-road bits to endure before they become on-the-road-bits, if you get my none-too-well-expressed, but beautifully-hyphenated meaning.

 

[davidsl500]

I accept some of the point that the load is spread over the surface area and therefore less cross width would force more front to back width to make contact in order to give the same lb/sq-in coverage, but there must be a diminishing aspect to this, especially allowing for the fact that the tyre pressures are identical or else why bother with wider tyres at all?

Thats my theory anyway.

Well actually I am told it is pretty consistent - the actual area of contact is the same. Too wide a tyre ruins the handling and the grip - might look good but I can tell you that my old Lotus 7 wouldn't go out in moist conditions let alone wet when I overtyred it !

Front to back contact is better because you get more of the tread pattern on the road which is essential for clearing rain water away - the tread can gather up the water and spit it out and it needs a length of tread in contact to achieve this. With an overtyred vehicle the same contact area is there overall but looking at the tyre, it seems that there is only a "point" contact across the width - hence why they are more prone to aquaplaning or loss of traction on take off"

I dont suppose going up one tyre size makes all that much of a difference though - unless you are on a track at the very edge.

 

[big x]

Well,
I thought I'd take my time and choose the best price/performance compromise and pick up a set at the end of the summer. Looked at my rears last night and the bit of tread I had left a couple of weeks ago has vanished. They are now as bald as me! (down to the bars anyway) Bugger - the fronts have around 1mm left so I guess they are going too.

As far as what to buy, reviews are so subjective, and in any case differ by model etc. Sure tyre x may last forever according to Mr Smith, but he has a focus and sits at 55. How will it cope with the torque on the back of my E? Or hauling the weight of an E down from 90 on the motorway day in day out. - no one really knows I guess.

I could get ones that appear to last, but the ride and noise could be awful.

So, I'm going to call the discount fitting station near the office. Ask for 2-3 options. Do a quick read, be no wiser and probably buy the middle one!

What the hell, if the wear rate of my current conti sport contact 2's is anything to go on (15.5k 75% motorway and new last November), I'll be changing them again by Christmas anyway!

I'm at a total loss to understand your post..why don't you download the AutoBild (mentioned earlyier) supersport test (a small fee is required) which includes the Continental sportcontact III, Goodyear F1 etc.

http://www.autobild.de/suche/suche....t=reifen+test&x=17&y=12&aktion=suche&center=0

 

[big x]

Well actually I am told it is pretty consistent - the actual area of contact is the same. Too wide a tyre ruins the handling and the grip - might look good but I can tell you that my old Lotus 7 wouldn't go out in moist conditions let alone wet when I overtyred it !

Front to back contact is better because you get more of the tread pattern on the road which is essential for clearing rain water away - the tread can gather up the water and spit it out and it needs a length of tread in contact to achieve this. With an overtyred vehicle the same contact area is there overall but looking at the tyre, it seems that there is only a "point" contact across the width - hence why they are more prone to aquaplaning or loss of traction on take off"

I dont suppose going up one tyre size makes all that much of a difference though - unless you are on a track at the very edge.

Yes, a wider tyre on the same wheel size has the same total contact patch area but of a different shape.

adam

 

[big x]

Well actually I am told it is pretty consistent - the actual area of contact is the same. Too wide a tyre ruins the handling and the grip - might look good but I can tell you that my old Lotus 7 wouldn't go out in moist conditions let alone wet when I overtyred it !

Front to back contact is better because you get more of the tread pattern on the road which is essential for clearing rain water away - the tread can gather up the water and spit it out and it needs a length of tread in contact to achieve this. With an overtyred vehicle the same contact area is there overall but looking at the tyre, it seems that there is only a "point" contact across the width - hence why they are more prone to aquaplaning or loss of traction on take off"

I dont suppose going up one tyre size makes all that much of a difference though - unless you are on a track at the very edge.

Yes, a wider tyre on the same wheel size has the same total contact patch area but of a different shape.To get more grip you need to go up a wheel size and fit lower profile tyres to maintain the same rolling circumference.

adam

adam

 

[jberks]

I'm at a total loss to understand your post..why don't you download the AutoBild (mentioned earlyier) supersport test (a small fee is required) which includes the Continental sportcontact III, Goodyear F1 etc.

http://www.autobild.de/suche/suche....t=reifen+test&x=17&y=12&aktion=suche&center=0

Primarily because my German isn't up to it.

I guess my point is that for the relatively small increase in grip gained by the better makes I'm prepared to compromise a little for the reduced cost. If I replaced tyres every 2 years as I used to, there would be no question. Bridgestones/contis etc would be all I'd consider - Ok pricey but pretty much a one-off expense.

But, as the rear contis have only lasted me 7 months, I simply can't justify £900 a year (and thats internet prices - phone quotes have been a lot higher) for tyres alone, not when I am being offered a similar (ok not quite as good, but close) option for £480 a year. Factor in that in all the reviews I have read, both professionally done and anecdotal, most of the budget brands punch well above their weight and I'm going to give them a go. On the upside, if they are a disaster, I'll get 6 months out of them, will have learned an important lesson and then pop a set of bridgestones back on.

I guess if I had the standard 225/16 the price gap would be smaller and I'd not be in this dilemma and whilst they look fantastic, the wider 17'' alloys are just too expensive to run for the type of use I put them through. But this car has far more grip than I've ever needed so even with slightly poorer tyres I should still have a decent margin over my needs. It is a diesel powered motorway cruiser, not a track day car after all.

 

[davidsl500]

As you say JB, its not as though this is a lifetime purchase! Actually your probably in one of the best positions to give a real input into tyre reviews - because of your tyre change frequency - see,there is good news to that hole in your wallet!

My SL doesn't do that sort of mileage so saving a couple of hundred every 2 years or so really isn't an issue.

We'll await your report !

 

[big x]

my point was that they are 245/45/17. Standard fitment on the avantgarde is 225/55/16 so I start with 20mm more tyre on the road than a normal avantgarde, at least in terms of width.

So, if they don't perform as well as a 245 conti (fair enough really) they should still perform as well as a 225 conti which would be in excess of what I need for even my most lunatic moments I suspect.

I accept some of the point that the load is spread over the surface area and therefore less cross width would force more front to back width to make contact in order to give the same lb/sq-in coverage, but there must be a diminishing aspect to this, especially allowing for the fact that the tyre pressures are identical or else why bother with wider tyres at all?

Thats my theory anyway.

Apart from looking good, one has to say, like most modern cars 245/45/17 is massively over tyred !
My 220 BHP E320 goes through 195/65/15 ! OK things have moved on but you pay for that rubber in increased noise,reduced ride quality,less grip in standing water and ice and less mpg.
The Hancook K105 225/55/16 seem to be around £80 at http://www.elite-design.co.uk/
I'm sure you could get them a bit cheaper,I find the Elite site useful for photo's of tread patterns.

adam

 

[Billy!!!!]

Try looking at this website www.mytyres.co.uk , put in your tyre size and they will list a whole load of tyres, select a tyre and then click on the tyretest link, tells you the rating for grip in wet,dry,snow noise and tyre wear.. I recomend the falken FK452..

 

[jberks]

Well I did it.

There is a problem with all this. If you want Contis, Pirrelli, Michelin etc, there is no real problem. Call up a fitter, and go down 2 hours later where the tyres are waiting for you.
However, if like me, £140+ per corner is a bit too heavy at the moment, they you have a dilemma. If you buy from mytres etc you have to order it, wait around a week, have someone available to accept delivery and that's if they have any in stock. Then you have to find a way of getting 4 massive tyres that won't go in the car, down to a fitter. If you go to the online mobile fitters, at the price I wanted to pay, they won't tell you waht you'll get - it comes under a 'budget' label and you get what you're given.

So, I called into my local guy, and was offered a similar deal. He had some Khumos on the floor and khumo was on my shortlist so I figured it was worth a shot. As I'd said before, it's probably only for 6 months anyway at the rate the £150 continentals wore out.


So I now have 4 shiny new 'Federal F595's'. They are ZR rated so should cope with my 80mph commute. They look a bit different but hey they only cost £83 ea fitted, balanced and done.
Amusingly I can't find any reviews on them whatsoever, so all the research came to nothing. The tyre guy reckons they are excellent though he would say that wouldn't he!

First impressions - the pattern would look more at home on a 2 door sports than my 4 door saloon but that's not a big issue. They are considerably quieter than the previous Bridgestone/conti mix. The ride is better - though some of that will be down to the extra rubber I now have. Grip, in so far as I have tested it seems equal too.

So, we'll wait and see.

 

[davidsl500]

Nice Tread !!

Actually they share some of the tread pattern characteristics of the F1's - Note the tyre centre is solid rubber round the circumference which is supposed to give good traction in the dry.

They aren't Kumho by the way !!

The company is called Federal and you need to buy a hat with Corks a dangling ! :

http://www.federaltyres.com.au/federal/index.htm

Still, interesting pedigree

Let us know how they go..

 

[jberks]

Thanks David, yes I knew they weren't khumo, that's what I was expecting but they gave me federals, which goes to prove the 'get what you're given' principle on these budget deals!

As you found, the only info on the web appears to be from the manufacturer who reckons they are great! Nice to hear if not exactly unbiased.

Anyway, so far so good, fairly quiet at 80 this morning and I took the opportunity to throw her round a roundabout during a thunder storm and she gripped perfectly. So, the only problem I can see now is if they wear out after 6k. If they last 10, then they will be acceptable value for money but not really any better than anything else. If I get 15k+ out of them, it will prove conventional wisdom wrong and score one for the budget boys.

watch this space .....

 

[jberks]

For general info, I thought I'd report back after 400 miles with my cheapies. It's too early to comment on wear. Grip is fine as is wet grip and noise. The only downside I can find is economy. MPG seems down. Time will tell if it improves again but whereas the computer would generally show 40-41 on the way into the car park, I'm now seeing low 39s and it's been fairly consistent. Going home, my 37 has dropped to 35 - something I generally didn't see unless I was pressing on. Economy had been slowly improving so I do wonder whether this had something to do with my old tyres slowly wearing out and the extra 5mm of rubber it now has to compress as the wheels go round, increasing resistance and I'd have seen the same effect whatever I replaced my old baldies with.

 

[Myros]

maybe it's the heat of the weather

It has been a bit hot recently. 28+C doesn't do much for your volumetric efficiency if you have been clocking it at our more usual 15-ish