255/60 R17 instead of stock 235/65 R17s?

[omodos]

Originally Posted by powers1

Sorry,I am bit late to this ,but just noticed it!Plus its also an ongoing thread!
If you say that Michelin claim that 255 is ok on a 7.5" rim,then they must have said it!I am sure BMW disagree ,otherwise they wouldnt fit a 255 on 8.5" and 9" rims ?
A 235 on a 7.5"(190.5) rim already sticks 2.2 cms on either side of the rim,a 255 on the same rim will increase that to 3.75 cms,creating even mode body roll.Ok for off road ,basically.I wouldnt want to drive it on the road going round curves with it,as it would also put too much strain on the tyre wall...eventually cutting it!

my 255 avon rangers spec says required rim is 8", but range is 7 -9 inch

[JCL]

Originally Posted by omodos

...just wondering if it is an alloy leak whether the leak could manifest itself only when car is in motion and alloy is under stress?

No. But if it is around the rim where the tire seals to the rim it can leak depending on the position when it is parked, ie sometimes and not others, depending on whether the area leaking is down or up.

[TwinsPoppa]

Originally Posted by omodos

my 255 avon rangers spec says required rim is 8", but range is 7 -9 inch

Per Tire Rack

Measured Rim Width

The measuring rim width is the industry standardized rim width upon which the tire must be mounted in order to confirm it meets its dimensional targets. Because the width of the rim will influence the width of the tire, a standard rim width for every tire size is assigned and must be used. This standardized measuring rim width allows all of the tires produced around the world to meet the same dimensional standards and therefore, be equivalent with regards to their physical size. The measuring rim width is sometimes referred to as the tire's "design rim width."


Rim Width Range

Because tires have flexible sidewalls, a single tire size will fit on a variety of rim widths. A tire's rim width range identifies the narrowest to the widest rim widths that the tire is designed to fit. The width of the rim will influence the width of the tire. A tire mounted on a narrow rim would be "narrower" than if the same size tire was mounted on a wide rim. NOTE: Because the overall diameter of a steel belted radial is determined by the steel belts, there is little, if any, change to the overall diameter of the tire due to differences in rim width.

WARNING:
Just because you can mount a certain tire size on a specific wheel width does not mean its ok to use that tire/wheel combination for your specific application.
You have to take into acct other Tire/Wheel specs to determine if it is okay to use in your application - like wheel offset, tire aspect ratio, tire overall diameter, etc.

[powers1]

Originally Posted by omodos

my 255 avon rangers spec says required rim is 8", but range is 7 -9 inch

Your OE 255s sit on 8.5"x18 wheels and the OE 19" set up,fits 255s on 9" wheel!
Anyone can do what they want!Maybe someone can fit a 255 tyre on 7.5" rim and give us some feedback!

[TriX5]

I have a set of Pirelli winters mounted as follows:

255/45 on 7.5x17
285/40 on 8.5x17

Looks fine, drives fine. YMMV and this is no guarantee for anyone else. It is simply a combo I happen to own and have driven. Clearly the OD of those tires is not a really good fit to an X5 but I used them for a few months until I could get a set of 18s.

Also, they're for sale but probably work better on a 3 or a Z4.

[omodos]

Originally Posted by JCL

No. But if it is around the rim where the tire seals to the rim it can leak depending on the position when it is parked, ie sometimes and not others, depending on whether the area leaking is down or up.

Hmmm not good news then, had audible leaks/then visible leaks once tires sprayed with soapy water solution on the front where tires seal with rim, and garage removed cleaned rims and applied bead sealer and leaks stopped...been religiously checking tire pressure cold and they are constant..although i read you lose 1psi per month through tire anyway as it is permeable...

[omodos]

Originally Posted by omodos

Thanks Fraser for the reply, will bear this in mind, at the moment one of my front tires seems to be losing air about 0.2bar per week (dropped from 2.2 bar to 2.0bar) just hoping not a cracked alloy will ask tire place to dunk it in water rather than use a soapy water spray only to find leak...just wondering if it is an alloy leak whether the leak could manifest itself only when car is in motion and alloy is under stress?

Ok my 0.2 bar or 3psi loss per week on one side was due to a pinhole sized puncture in the tread! had to really push garage to take it off and check (me owing him about 150 dollars for the used alloys could have been the reason for this reluctance) anyway sprayed with water it showed a tiny leak...and they plugged it so far so good

[JCL]

Well it is good news, since that could have been your slow leak on the other tires. Cleaning and sealing the bead is all it takes.

You mention plugging the tire in your other post. Hope they plugged it from the inside with a combination inside patch/plug, and didn't just stick a plug in it from the outside.

[omodos]

Yup both used, but having said that both my previous repairs the garage just plugged the hole from outside with no problem....