Will 245/40/18 tyres fit 8" wide rs4 wheels

**rhencullen1989** · 23-07-2009,10:04 PM

Hi, i currently have Goodyear eagle F1 GSD tyres on my 2004 s-line quattro, which has the standard 18" 5 spoke ronal rs4 wheels.

I want to buy the same tyres again but they are not available in 235/40/18. Will 245/40/18 fit or will they rub somewhere, basically they will be 10mm wider (5mm extra inside and 5mm extra outside).

**kite** · 23-07-2009,11:52 PM

F1 GSD have been replaced with assymetric (sp) tyres.
I have just replaced all 4, 235/40/18, paid just a smidge over £500

**rharris** · 23-07-2009,11:59 PM

And these won't be 10mm wider

40% of the 10mm will be the sidewall. so 4mm extra height and 6mm extra width...

but anyway, it seems someone has provided an answer on availability of the sizes you currently run....

**xenon** · 24-07-2009,08:03 AM

Originally Posted by rharris

And these won't be 10mm wider

40% of the 10mm will be the sidewall. so 4mm extra height and 6mm extra width...
.

Sorry, but you are wrong. 245 is the width of the tyre in millimeters which in my book is 10 mm more than 235 mm. However, you are correct in saying that the sidewall will be 4 mm higher which results in the tyre being 8 mm bigger in diameter

**rharris** · 24-07-2009,09:25 AM

Yeah; sorry - you are right. I always though that value was the 'length' of rubber that goes from rim-to-rim (sidewall+tread+sidewall) and then the second value the % of that which was sidewall - but you're right it is just the width of the tread part.

Learn something new everyday

**rhencullen1989** · 24-07-2009,12:14 PM

I know that Goodyear do the new Eagle Assymetric tyre, but it does not LOOK as good as the older F1 GSD tyre which looked like a cut slick.

So, will 245 width fit or will it rub/mess up the handling. Someone must have tried to fit wider tyres, what about insurance, will they decline to pay out in the event of an accident because the tyres were the incorrect size?

**xenon** · 24-07-2009,01:34 PM

If the tyre and/or rim is not a standard fitment for your car the you declare to your insurance company. Some will not be bothered unless the tyre comes outside of the bodywork.
On a practical level, the tyres will fit the rims OK but cannot say if they will rub or not (you haven't mentioned what car you intend on fitting the wheels to). You could try checking the clearances yourself to determine if there is enough to accommodate the wider tyre. If you are still unsure then you could take it to a tyre specialist and they may be able to advise whether the wider tyre will fit OK or not.

**symonc1** · 10-08-2009,07:31 PM

245/40/18 means 40mm high of rim 245 means total width below tire tread.... so 245mm wide.............
but did you no your wheel will be 9.5 inch wide not 8" same gose for the 18" it will more likly be 19.5"............ edge to edge...

**rharris** · 10-08-2009,07:40 PM

the 40 is a % of the 245 - not 40mm...

**symonc1** · 10-08-2009,07:44 PM

mate i can see where your coming from but after making around 4000 tire a month i got the jist of what the rite sizes mean......... no %just basic mm ....cheers buddy