E89 winter tyre size question.

[brittas]

I have a set of winter tyres from my old car. These are 245 /40 /18.

I will be buying a set of non staggered wheels for these tyres next winter. Normally the wheels are 8J
The recommended size for a non staggered set of 18" are 225/ 40 /18.

Will 245/40/18 x4 be ok to use as a winter set on a 8J wheel?

 

[David-H]

Should be OK as long as you have the right offsets on the new rims.

 

[sars]

The handbooks recommended size for winter tyres is 225/45/17, but there is no problem in going to 225/40/18. If your car has a manufacturers warranty then I would personally stick with the recommended tyre sizes, that's just because I would not run the risk of a potential transmission/suspension/steering claim being rejected because of the fitting of a wrong sized wheel, there are also insurance implications too.

If you are out of warranty, the implications for fitting wider and thus larger diameter tyres are: -

1 - Slightly increased stress on the steering mechanism
2 - Changed speedometer error (This may well be a benefit as they read fast, as you will actually be going faster for the same indicated speed)
3 - Poorer fuel economy
4 - A car less quick to accelerate.

Many on here have changed diameters without issue and Engineers inherently design safe with excess safety built in, so.......

 

[brittas]

It is 245/40/18 I will be fitting .225 would be fine. I believe 245 is the maximum width for a 8J wheel. I may try and sell these tyres next winter and put correct ones on. Don't want to take any risks.

 

[KERMIT1970]

It is 245/40/18 I will be fitting .225 would be fine. I believe 245 is the maximum width for a 8J wheel. I may try and sell these tyres next winter and put correct ones on. Don't want to take any risks.

I fitted square winter set up on 18's after speaking to techs at BMW was going 245/40/18 but told to go 225/40/18 on 8j rims. Fitted 20mm spacers to rears as I felt they look too far in the rear arch. :