Can I replace my 235/40/ZR18 91Y with a 235/40/ZR18 95Y?
Discussion
I am basically looking to replace just one of my rear tyres on the T350C as the other rear tyre was fitted afterwards following a puncture.
I currently have 235/40/ZR18 91Y fitted on the rears, but when looking around it seems that all I can now find is the same tyre but with the spec: 235/40/ZR18 95Y.
I have deduced that the 91Y tyre is a 'reinforced' tyre but the 95Y is a 'reinforced extra load' tyre.
Can I have a 91Y and a 95Y on the same axle? Does it make any difference at all as all the other dimensions and specs of the tyre are the same?
I currently have 235/40/ZR18 91Y fitted on the rears, but when looking around it seems that all I can now find is the same tyre but with the spec: 235/40/ZR18 95Y.
I have deduced that the 91Y tyre is a 'reinforced' tyre but the 95Y is a 'reinforced extra load' tyre.
Can I have a 91Y and a 95Y on the same axle? Does it make any difference at all as all the other dimensions and specs of the tyre are the same?
On a performance car,I would not run different tyre load rated tyres on the same axle,the higher load rated tyre is designed to run at a higher pressure,so if you ran the same pressure in each tyre this would have some effect on the balance and handling of the car,due to the stiffer side wall on the extra load tyre.
MK INDY said:
On a performance car,I would not run different tyre load rated tyres on the same axle,the higher load rated tyre is designed to run at a higher pressure,so if you ran the same pressure in each tyre this would have some effect on the balance and handling of the car,due to the stiffer side wall on the extra load tyre.
Im with this man, I wouldnt run different ratings on the same axle.
The difference is what load weight the tyre is designed to support and work well with.
This often translates to stiffness of the sidewall. Since a TVR is unusually light, the problem is getting a tyre, which is correct in other ways, with a sidewall soft enough to suit the TVR.
Sticking odd tyres on an axle can produce odd results and is best avoided. You will probably get away with it without noticing the difference. Until one day it turns around and bites you.
This often translates to stiffness of the sidewall. Since a TVR is unusually light, the problem is getting a tyre, which is correct in other ways, with a sidewall soft enough to suit the TVR.
Sticking odd tyres on an axle can produce odd results and is best avoided. You will probably get away with it without noticing the difference. Until one day it turns around and bites you.
Thanks for all the comments - arguments seem to make sense.
Just got off the phone with a very helpful Mr Denton who took time out of his day to answer my questions and in his opinion it really will make very little difference going UP a load index on the tyre if all other spec and brand are the same on the axle. It is a big No No to go down a load rating but in the real world going up is fine and does not require different pressures etc..
Apparently many of the tyre maufacturers to save costs actually manufacture a large number of tyres to a higher load rating and badge them up with lower load indexes to suit manufacturer requirements. This way they produce 1 tyre across 4 product ranges which saves manufacturing costs.
Big thanks to that man Bomber Denton....
ETA...
Also just had a call back from Pirelli Technical and whilst they have never conducted tests on vehicles with that spec of tyre and two different load ratings, they see no reason why it would affect the car adversely.
Just got off the phone with a very helpful Mr Denton who took time out of his day to answer my questions and in his opinion it really will make very little difference going UP a load index on the tyre if all other spec and brand are the same on the axle. It is a big No No to go down a load rating but in the real world going up is fine and does not require different pressures etc..
Apparently many of the tyre maufacturers to save costs actually manufacture a large number of tyres to a higher load rating and badge them up with lower load indexes to suit manufacturer requirements. This way they produce 1 tyre across 4 product ranges which saves manufacturing costs.
Big thanks to that man Bomber Denton....
ETA...
Also just had a call back from Pirelli Technical and whilst they have never conducted tests on vehicles with that spec of tyre and two different load ratings, they see no reason why it would affect the car adversely.
- This was not a recommendation or OK from Pirelli in any way but a generic comment that going UP the load rating is not considered a huge problem**
Edited by stub101 on Thursday 8th October 13:50
Maybe thats why it is so hard to get tyres that really are suitable for a lightweight car?... I can still recall someone on here replacing TVR T1S's with generic T1S's complaining about the significant difference (was subjected to much 'you haven't christened them properly' debate ).
Just sticking the 'stiffer' tyre on the drivers side, might be a good tip for Fester anyway
car screams for mercy when he just sits in it from what he has fessed up to
Just sticking the 'stiffer' tyre on the drivers side, might be a good tip for Fester anyway
car screams for mercy when he just sits in it from what he has fessed up to
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