Tyre size and rating 996
Discussion
I have 18 wheels and am currently running the vehicle on 225 ZR 40 front and 265 ZR 35 back all weather tyres. These are the correct size tyres for the winter tyre option. The summer tyre option has the same size for the front, but the back option is 285 with a profile of 30. All these sizes give the same rolling circumference for each wheel.
I don't want to change between winter and summer tyres. However, when I look on the various web sites for a 285 all weather I cannot find one. All the tyres of this width and profile are marked as summer.
There is nothing which says I cannot run on 265 ZR 35 all weather all year round at the back. These tyres have the correct load and speed rating and are within the width tolerances for back wheels.
Is it the case that 285 30's are only made as a summer tyre?
I don't want to change between winter and summer tyres. However, when I look on the various web sites for a 285 all weather I cannot find one. All the tyres of this width and profile are marked as summer.
There is nothing which says I cannot run on 265 ZR 35 all weather all year round at the back. These tyres have the correct load and speed rating and are within the width tolerances for back wheels.
Is it the case that 285 30's are only made as a summer tyre?
The correct rear tyre size for your car is the 285/30 18 for summer tyres, for winter tyres, the recommendation is for a taller/narrower tyre,hence the 265's you have fitted.Nothing wrong with keeping the all weather tyres fitted all year round,it just that they'll wear down more quickly on warmer roads and offer less grip and less precise handling over the summer.Your call tbh, if you are happy,and are not going to do track days or tear around at high speed, then leave what you have fitted.
That's the view that I take, in that I cannot be found at fault by an insurance company in running the right size (265) all weather tyres in summer. However, if I have on 285 summer tyres on in winter I could be found at fault in the event of a claim. In terms of my driving on UK roads I don't think I would notice the difference between 265 and 285 tyres.
I had wondered if my unsuccessful search for 285 all weather tyres had just been because of the current time of year (May/June) in that they would not be available.
I have another vehicle on which I run mud and snow tyres throughout the year, as I sometimes drive that vehicle in Alpine regions when snow tyres are mandatory. That seems a fairly clear cut issue.
I had wondered if my unsuccessful search for 285 all weather tyres had just been because of the current time of year (May/June) in that they would not be available.
I have another vehicle on which I run mud and snow tyres throughout the year, as I sometimes drive that vehicle in Alpine regions when snow tyres are mandatory. That seems a fairly clear cut issue.
My car is 2003 facelift model. The handbook is a matching date in terms of its printing.
The handbook says the following for 18" wheels with either 7.5/8 J Front and 10J rear rims:
Summer. Front 225/40 ZR 18 Back 285/30 ZR 18
Winter. Front 225/40 R 18 88 H M&S. Back 265/35 R 93 H M&S
For winter there is no ZR Rating, but clearly the car needs ZR and for summer there is no weight rating stated.
I have therefore taken the view 265 ZR for the rear are OK all year round as they are a specified dimension, speed and load rating. The handbook does not say that 265 should not be used in summer, which is sensible.
Furthermore, the 17" wheel for the rear is 255 for both summer and winter on a 9J rim. So by running 265's all year round I am well within all weather tolerances.
All interesting stuff
The handbook says the following for 18" wheels with either 7.5/8 J Front and 10J rear rims:
Summer. Front 225/40 ZR 18 Back 285/30 ZR 18
Winter. Front 225/40 R 18 88 H M&S. Back 265/35 R 93 H M&S
For winter there is no ZR Rating, but clearly the car needs ZR and for summer there is no weight rating stated.
I have therefore taken the view 265 ZR for the rear are OK all year round as they are a specified dimension, speed and load rating. The handbook does not say that 265 should not be used in summer, which is sensible.
Furthermore, the 17" wheel for the rear is 255 for both summer and winter on a 9J rim. So by running 265's all year round I am well within all weather tolerances.
All interesting stuff
Hilux2400 said:
My car is 2003 facelift model. The handbook is a matching date in terms of its printing.
The handbook says the following for 18" wheels with either 7.5/8 J Front and 10J rear rims:
Summer. Front 225/40 ZR 18 Back 285/30 ZR 18
Winter. Front 225/40 R 18 88 H M&S. Back 265/35 R 93 H M&S
For winter there is no ZR Rating, but clearly the car needs ZR and for summer there is no weight rating stated.
I have therefore taken the view 265 ZR for the rear are OK all year round as they are a specified dimension, speed and load rating. The handbook does not say that 265 should not be used in summer, which is sensible.
Furthermore, the 17" wheel for the rear is 255 for both summer and winter on a 9J rim. So by running 265's all year round I am well within all weather tolerances.
All interesting stuff
In my 996.1 handbook it shows 18” summer but only 17” for winter tyres. The handbook says the following for 18" wheels with either 7.5/8 J Front and 10J rear rims:
Summer. Front 225/40 ZR 18 Back 285/30 ZR 18
Winter. Front 225/40 R 18 88 H M&S. Back 265/35 R 93 H M&S
For winter there is no ZR Rating, but clearly the car needs ZR and for summer there is no weight rating stated.
I have therefore taken the view 265 ZR for the rear are OK all year round as they are a specified dimension, speed and load rating. The handbook does not say that 265 should not be used in summer, which is sensible.
Furthermore, the 17" wheel for the rear is 255 for both summer and winter on a 9J rim. So by running 265's all year round I am well within all weather tolerances.
All interesting stuff
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