Tyres - Different Aspect Ratio on same car!

[Candive]

I purchased a Holden privately. When I inspected the cars tyres, they all looked in good condition with a lot of tred left. Today I got a flyer from one of the local tyre shops and I became curious as to how much it was going to cost me to replace my tyres in the future. I went out to read the side walls and I was surprised to find the following anomaly. Three tyres are 225/R50/16 and the one on the passenger rear is 225/R55/16. Odd?

Now the tyres are in very good condition and I don't really want to replace a perfectly good tyre unless I really have to. Obviously, different size tires are an issue on the same vehicle but is 55 versus 50 something to be really concerned about?

[GetToDaChopa]

Mine are like that on the VH. The front has a lower profile than the back. Now that you bring it up i'd like to know as well, if it will be a problem.

[Calaber]

Different profiles on the same axle are a problem. Different profiles at each end of the car are not necessarily.

If you mix profiles on the same axle, you could have a larger radius on one side of the car than the other, meaning that one wheel is spinning faster than the other at any speed. If the wheels are connected through a differential, you can imagine what this means to the diff. It is constantly compensating for the varying revolutions from one side to the other. There are other problems too and anybody who has different tyre sizes on the same axle needs to get the problem fixed.

[VKCOMMO]

I purchased a Holden privately. When I inspected the cars tyres, they all looked in good condition with a lot of tred left. Today I got a flyer from one of the local tyre shops and I became curious as to how much it was going to cost me to replace my tyres in the future. I went out to read the side walls and I was surprised to find the following anomaly. Three tyres are 225/R50/16 and the one on the passenger rear is 225/R55/16. Odd?

Now the tyres are in very good condition and I don't really want to replace a perfectly good tyre unless I really have to. Obviously, different size tires are an issue on the same vehicle but is 55 versus 50 something to be really concerned about?

the 55 will wear more than the 50 on the inside... to save the diff id say move the 55 to the front if you really don't want to buy new tires

[GetToDaChopa]

the 55 will wear more than the 50 on the inside... to save the diff id say move the 55 to the front if you really don't want to buy new tires

How will it wear more? if anything the 50 will wear more since it's doing more revolutions, even then you prob won't notice it.

[VKCOMMO]

the inside of the wheel will be taking alot of the wright, and not spreading it out evenly.. its just like when your alignment is out

[Candive]

Thanks for the advice guys. In the end I decided to buy an R50 to match the other 3 and used the R55 as the spare. The fellow at the tyre shop told me that the vehicle originally came with R55's. Obviously they needed replacement so the previous owner used the good spare and bought three new tires. He probably chose the R50's because they were on sale. He then took the best of the worst R55's and put it in the boot as the spare.

As time goes on, I'll probably migrate back to the R55's. It may be in sets of two so that I keep the same size tyre on the same axel. As for the new tyre, I got it at Marks and Walling in West Ryde.

Thanks again