tyres 225 want to put on 245

[DanGB]

when your parking at slow speeds mate.

[The Wheel Man]

when your parking at slow speeds mate.

So how much force do you think is needed to compress 3mm of rubber with a car?? 

[Hurdy]

Swap the TTS alloys as well they are 8" wide and will look much better with the 245's. Add to that the missis rolling on Monza's on 225 sections and it should slow her up a bit

[Teutonic_Tamer]

The 245/35/18 is 6mm smaller in diameter than a 225/40/18,

Huh - actually more like 8 or 9mm difference in diameter!  4.5mm is the radius, and therefore the ride height! 

(225/40 ZR18 has an overall dia of 637 to 645mm - depending upon manufacturer [Toyo or Mich], whereas 245/35 ZR18 has an OD of 629mm [Toyo])

take into account the squashing effect and they will be about the same.

WTF are you on about?  If the load rating and the tyre pressures are the same, then the "squashing effect" will be identical, therefore the ride height will 4.5mm lower!

TBH, ive fitted 245 to a 7.5 rim before and i diddnt like the look..... each to there own though!!

Yup, agreed, ETTO.

And just to clarify, a 245 is NOT recommended for a 7.5" rim - with 8.0 to 9.5 being the recommended rim widths.

took them off wifes new tts cos the buffers on the side didnot protect the wheels u know what i mean 2 scuffed wheels in 2 days of picking it up.

The so called "rim protector" is a load of rubbish IMO.  How is a small strip of rubber 3mm deep going to stop 1200kg of car from hitting a wheel on a kurb? 

Ahhhh, but different tyre manufacturers use different methods of "rim protectors".  Pirelli, along with most of the Jap and Korean tyres use the useless rubber "lip" mentioned.  However, Michelin, the latest Continental, and Dunlop - all use the entire height of the sidewall as a rim protector.  This method is noticably more useful than the pathetic 3mm lip still used by inferior tyre manufacturers.

[trix]

i think i will just try them all a bit two technical.will they or wont they rub that was the question.x

[The Wheel Man]

Ref TT: Agreed on the OD, got my sums wrong (no surprise there!)

What i mean by the squashing effect is that the 245 tyre will be pushed in by the 7.5" rim.  The majority of the width will overhang the alloy but i would have thought that there would be a small increase in the height of the tyre (based on no more than what i think would happen, i woulddnt fit this combo to a customers car so i cant say for sure)

i think i will just try them all a bit two technical.will they or wont they rub that was the question.x

I think that joesgti answered you question on this

[Teutonic_Tamer]

Ref TT: Agreed on the OD, got my sums wrong (no surprise there!)

OK, no worries.  Afterall, what's a few mm between mates? 

What i mean by the squashing effect is that the 245 tyre will be pushed in by the 7.5" rim.  The majority of the width will overhang the alloy but i would have thought that there would be a small increase in the height of the tyre (based on no more than what i think would happen, i woulddnt fit this combo to a customers car so i cant say for sure)

Ahhhh, I see exactly now.  Yes, agreed, the 245 on a 7½" rim will have a "ballooning" effect, an un-natural kind of bulge in the sidewall.      I suppose it's no different to the current trend of "stretching" - which, IMEVHO, must be THE worst mod going - I think that particular trend looks really aweful.      ETTOT.