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Kind of...

The profile number is actually a percentage of the tread width so theoreticaly it will, but like I said, the attessa system can handle a small amount of variation. I think it was Sydneykid that stated 5-10% so maybe PM him and ask where he got that info, and you should be able to calculate the difference from there.

But no, the width itself won't make a difference.

Do you guys think it'll be okay to put the current 215/50's in the front and get new 225/50's for the rear? The tyre width shouldn't matter to the rolling diameter should it?

I suggest you get the same size tyres front and rear - the profile is calculated as a percentage of the width, so if you have different widths front and rear, but the same profile, then the rolling diameter will still be different, so you'll run into the same problems again.

eg 225/50/17 works out as:

225 = width of the tyre tread surface in millimetres,

50 = 50 percent of the tyre width

17 = made to fit a 17" diameter wheel.

Basically, and changes you make towards going to a wider or narrower tyre, or lower or higher profile, they all affect the total rolling diameter of the wheel and tyre combo...

I suggest you get the same size tyres front and rear - the profile is calculated as a percentage of the width, so if you have different widths front and rear, but the same profile, then the rolling diameter will still be different, so you'll run into the same problems again.

eg 225/50/17 works out as:

225 = width of the tyre tread surface in millimetres,

50 = 50 percent of the tyre width

17 = made to fit a 17" diameter wheel.

Basically, and changes you make towards going to a wider or narrower tyre, or lower or higher profile, they all affect the total rolling diameter of the wheel and tyre combo...

I see, i'll look for the appropriate ones then.

Are these calculations right though?

Front 215/50 = 107.5

with either (rears)

A. 225/50 = 112.5

B. 235/45 = 105.75

If I go with A, the percentage is 107.5/112.5 = approx. 5% diff.

If I go with B, the percentage is 105.75/107.5 = approx. 2% diff.

Side question... what's the funny vibration/fart it does when i turn the engine off? It's like a vibration lasting a second, feels weird. Feels like it's coming from the drive or something.

Edited by webng
Side question... what's the funny vibration/fart it does when i turn the engine off? It's like a vibration lasting a second, feels weird. Feels like it's coming from the drive or something.

Apparently this happens if your 50/50 torque split button is on.Mines definitely OFF though, strange...

definately ! the roads into and out of Strathalbyn were "nicely" paced :P

good to see my Stag kept up power wise with the best of them - great to know :D handled brilliantly thru the faster twists as well

definately ! the roads into and out of Strathalbyn were "nicely" paced :ninja:

good to see my Stag kept up power wise with the best of them - great to know :thumbsup: handled brilliantly thru the faster twists as well

It looked and sounded GREAT from the back for sure!

  • 4 weeks later...

Hello all from across the pond!

I'm researching a problem that I'm having over here in the UK, and was wondering if you managed to find a solution to your issue with the 4WD light coming on.

I have a Stagea over here, exhibiting exactly the same symptoms. All 4 tyres are the same, all replaced at the same time, but I get the slight juddering while driving along at constant speed occasionally.

Sometimes it can go for weeks without happening, sometimes as soon as I get to the end of my road it'll start.

If I turn it off and on (Microsoft Reboot Engineer tactics) it works fine after that (sometimes).

Did you find a fix for the problem at all?

Hello all from across the pond!

I'm researching a problem that I'm having over here in the UK, and was wondering if you managed to find a solution to your issue with the 4WD light coming on.

I have a Stagea over here, exhibiting exactly the same symptoms. All 4 tyres are the same, all replaced at the same time, but I get the slight juddering while driving along at constant speed occasionally.

Sometimes it can go for weeks without happening, sometimes as soon as I get to the end of my road it'll start.

If I turn it off and on (Microsoft Reboot Engineer tactics) it works fine after that (sometimes).

Did you find a fix for the problem at all?

Have you checked your Attessa fluids? Drivers side, in the boot, in the little parcel shelf like bit. There is the atessa resevoir in there. You can use Auto transmission fluid to top up.

My juddering was rectified after i changed the tyres so the rolling dimensions were very very close.

under the front passenger seat is a cable that runs from the attessa computer to the ecu, I think.

mine was 'perforated' when we installed a cdstacker under the seat. 4wd flashed randomly and had me rather stressed.

check the cable for abrasions, check the fluid too, might require a bleed ?

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