UK tyre depth

neilmcl

sevenhills wrote: »

A smaller sized tyre will feel the bumps more than a large tyre, maybe the Golf has small tyres/wheels.

Wheel size has nothing to do with it. It's the tyre's profile that makes the biggest difference. The majority of larger, sportier alloys will be sitting on wide and low profile tyres and it's these that are the problem rather than small wheels and fatter tyres that can handle our poor British roads much better.

Iceweasel

neilmcl wrote: »

And a lot of new, expensive cars drive on thin, rock hard, unforgiving run flat tyres with stiff, sporty suspension. hardly giving you the feeling of "floating on air". What experience do you have of driving luxury, or even new cars?

The latest Run-Flats are supposed to be only 3% stiffer in the sidewalls - I doubt if anyone could detect 3% with the seat of their pants.

Large diameter ultra low profile tyres will defo make the ride harsher though.

I refuse to go larger than 18" and lower than 40 aspect.

neilmcl

Iceweasel wrote: »

The latest Run-Flats are supposed to be only 3% stiffer in the sidewalls - I doubt if anyone could detect 3% with the seat of their pants.

Large diameter ultra low profile tyres will defo make the ride harsher though.

I refuse to go larger than 18" and lower than 40 aspect.

Trust me, ask any driver that's swapped between RFTs and normal tyres and the majority will tell you there's a world of difference. I agree they've definitely improved in recent years and for me their benefits currently outweigh any reason to change them myself.

Iceweasel

neilmcl wrote: »

Trust me, ask any driver that's swapped between RFTs and normal tyres and the majority will tell you there's a world of difference. I agree they've definitely improved in recent years and for me their benefits currently outweigh any reason to change them myself.

I changed from the dreaded Bridgestone Potenza runflats to Continental ContiSport2 runflats - and there was a world of difference.

The latest CSC5s and CSC6s are much better yet again.

Not all run-flats are created equal.

Most people's opinions on run-flats were formed and based on the first generation which were pretty rough.

I just hope that they were not put off them for ever.

I too find the benefits far outweigh any negatives - if there are any left these days.

sevenhills

neilmcl wrote: »

Wheel size has nothing to do with it.

Just because you say so, does not make it true. A 13" wheel/tyre has very different handling properties to a 19" wheel/tyre

neilmcl

sevenhills wrote: »

Just because you say so, does not make it true. A 13" wheel/tyre has very different handling properties to a 19" wheel/tyre

Again the wheel size is irrelevant it's the profile of the tyre that makes the difference. To give you a bit of an extreme example, you do realise that Formula 1 cars run on 13" rims right.

sevenhills

neilmcl wrote: »

Again the wheel size is irrelevant it's the profile of the tyre that makes the difference. To give you a bit of an extreme example, you do realise that Formula 1 cars run on 13" rims right.

Not a good example, they have not chosen 13" for better comfort/ride.

neilmcl

sevenhills wrote: »

Not a good example, they have not chosen 13" for better comfort/ride.

OK, I'll make it simple for you as you don't seem to be getting it. The majority of every day, small and family cars are running on 15" and 16" wheels with larger profile tyres. There's a very good reason for this, it's because they offer the best comfort, economy and overall driving characteristics for those types of car. When you start looking at higher performance, so-called "sportier" models then you'll see they tend to be all on 18" wheels and above with wide, ultra low profile wheels and whilst it can be argued they're offer improved handling in a sportier environment this is usually to the detriment of overall comfort and economy.

You don't have to take my word for it but simply stating smaller wheels are inferior to larger ones when it comes to handling poor road surfaces is far too simplistic and utter codswallop.

Rhenser

sevenhills wrote: »

Here in the UK we have quite low standards when it comes to tyres. How do we compare to the rest of the world?
I have a local garage that call them selves 'German Tyres' because all there tyres come from Germany. Germany have a 4mm depth law, yet our law is 1.6mm across 75% of the tyre. Is that right?

So a tyre cab be wearing badly on the edge, yet the 3 central treads are above 2mm, so the tyres are perfectly legal.

What are the legal limits in other countries, perhaps there should be minimum standards, set by the EU?

No, I am sorry, but that is not the correct position regarding the current regulations in Germany.

Germany's regulations relating to tyre profile depth are the same as in the UK, at least for passenger cars.
That is 1.6mm across 75% of the contact surface for the entire circumference of the tyre.

The significant difference in how we use tyres in Germany compared to the UK is that in Germany we have always traditionally had winter and summer tyres. Many people have 2 sets of wheels & tyres; a nice set of rims and summer tyres for use between Easter and October, and another set of rims (often steel) with 'winter' tyres for use October to Easter.

Back in 2010, the law was clarified in Germany. What many simply referred to as 'winter' tyres were defined as M+S (Matsch + Schnee / mud & snow). This means all weather/ all year tyres are included so long as they are M+S certified.
So what the regulations effectively now mandate is that Summer Tyres are not permitted to be used during icy conditions (snow, ice, frost, etc) - the regulations do not specify dates, only icy conditions.

The UK generally use all-weather tyres. Snowfall is rare in the UK due to it's temperate climate, which is fortunate as when it does occur, even as little as 5mm seems can bring the UK to a standstill.

The permitted (by law) profile depth in Germany is the same no matter what type of tyre, although it is generally accepted that a 'winter' tyre should always have more depth than the legally permitted minimum to be effective in handling the mud & snow it is designed for.

sevenhills

neilmcl wrote: »

OK, I'll make it simple for you as you don't seem to be getting it. The majority of every day, small and family cars are running on 15" and 16" wheels with larger profile tyres. There's a very good reason for this, it's because they offer the best comfort, economy and overall driving characteristics for those types of car. When you start looking at higher performance, so-called "sportier" models then you'll see they tend to be all on 18" wheels and above with wide, ultra low profile wheels and whilst it can be argued they're offer improved handling in a sportier environment this is usually to the detriment of overall comfort and economy.

You don't have to take my word for it but simply stating smaller wheels are inferior to larger ones when it comes to handling poor road surfaces is far too simplistic and utter codswallop.

As you say, the 15/16" wheel/tyre has better comfort and economy; they tend to not use the 13" quite so much. Minis and Metro used to have 10"-12" wheels/tyres.
Even formula 1 are pushing for larger wheels.

http://www.speedhunters.com/2014/07/formula-1-13-inch-versus-18-inch/