Tyres

[Tootall]

My ZTT is due for a pair of tyres soon, i am sure this question has been asked many times before but here i go;
Will changing from 225/45 R18,s to 225/40 R18,s make much difference to things like speedo reading, road nosie, handing etc.
Many thanks in advance.

[Alex30013k]

I would say the ride would become harder, more road noise,

But i think the change in the speedo will be so little its not worth worrying about?

[GreyGhost]

My ZTT is due for a pair of tyres soon, i am sure this question has been asked many times before but here i go;
Will changing from 225/45 R18,s to 225/40 R18,s make much difference to things like speedo reading, road nosie, handing etc.
Many thanks in advance.

Hello Toots

It's all very well changing to a 40 tyre but do take into consideration that the wheels are built to optimally use a profile of 45 not 40. Therefore in high stress conditions they mail fail to perform as the correct profile tyre.
The handling will be compromised but not to any great extent until the maximum stress situation.
There will be little or no difference in speedo readings as the rolling radius remains very nearly the same. (Taking into account + or - 10% error on speedo readings).
I cannot offer an opinion an noise or wear as I have not any real world experience of the 40 profile.

Personally I would stick with the manufacturers recommendations for tyre sizes, They did as you are aware spend many millions developing the cars to run on a particular size tyre.

I am aware that the tyre size you propose has been used by others so I would wait for their opinions before proceeding.

[Roverron]

Also consider the insurance implications of fitting a size not listed by the manufacturer....

Ron

[actros]

Hello Toots

It's all very well changing to a 40 tyre but do take into consideration that the wheels are built to optimally use a profile of 45 not 40. Therefore in high stress conditions they mail fail to perform as the correct profile tyre.
The handling will be compromised but not to any great extent until the maximum stress situation.
There will be little or no difference in speedo readings as the rolling radius remains very nearly the same. (Taking into account + or - 10% error on speedo readings).
I cannot offer an opinion an noise or wear as I have not any real world experience of the 40 profile.

Personally I would stick with the manufacturers recommendations for tyre sizes, They did as you are aware spend many millions developing the cars to run on a particular size tyre.

I am aware that the tyre size you propose has been used by others so I would wait for their opinions before proceeding.Hi all can anybody put a light on this ? i have been told that in Germany you must have a certain amount of tread depth can anybody say what it is.
bri :cool2: :driving:

[Dave Goody]

Hi all can anybody put a light on this ? i have been told that in Germany you must have a certain amount of tread depth can anybody say what it is.
bri :cool2: :driving:

I used to travel to Germany regularly in my 75 and as the car was a lease vehicle I used to have regular upsets with the lease company as they would not change the tyres until they reached uk minimum 1.6mm ? in Germany I think it is 3mm which is why 2nd hand tyres appear on the market with about 3mm of tread. Can anyone maybe Juergen? corroborate this? Dave

[Ken]

Hi all can anybody put a light on this ? i have been told that in Germany you must have a certain amount of tread depth can anybody say what it is.
bri :cool2: :driving:

Bri

All I can find is this but it don't say its the law.


Stopping distance on wet roads
For example, it is common practice in countries such as Germany to replace tyres when the tread depth has worn to 3mm,

Why don't you PM Juergen?

Ken

[actros]

Bri

All I can find is this but it don't say its the law.


Stopping distance on wet roads
For example, it is common practice in countries such as Germany to replace tyres when the tread depth has worn to 3mm,

Why don't you PM Juergen?

Ken
HI Ken & all got a pm from our friend in germany and he says that the min depth is 1.5 mm so this has cleared that point up.:bowdown:

[tigerchubs]

Tread Depth and the Law

The legal minimum tread depth for car and similar tyres in the United Kingdom and throughout the European Community is 1.6mm throughout a continuous band comprising the central three quarters of the breadth of tread and round the entire outer circumference of the tyre.

[Tootall]

Thanks for the replies people looks like if will stay O/E sizes then and refit some more B#W badged tyres :rolleyes: