Different Front And Back Set Of Tyres Stagea Nm35

[samuri]

NM35 stagea axis autech

Are there any recriminations from running 245 45 18 tyres on the front

in particular the aspect of attessa

awd handling ,safety ,legality or speedo readings or anything serious

and running 225 45 18 on rear.?

back tyres are average quality and 12,000k old.......

front tyres will be new and excellent Goodyear Eagle F1 Asymmetric 2

I am a little concerned I may cause mechanical damage from a post elsewhere on the stagea awd

Edited February 8, 2016 by samuri

[Brick]

I have never seen someone run wider tyres at the front. Interesting.

Basically though, the system can deal with something like a 2% variance in tyre size front to back so it can deal with uneven tyre wear.

[KiwiRS4T]

It is the rolling circumference that matters so you will need to measure them. They will be different but maybe as Josh says not enough to cause a problem.

[scotty nm35]

Personally I wouldn't, just run the same size tyres to protect your attessa clutch packs and driveshaft uni's.

[sav man]

I had 245/45/18 fitted to the front of my car by mistake and still had 245/40/18 on the rear. The car hated life, it shuddered all the time and the 4wd light kept coming on.

Tyre place fixed it up pretty quick and got 245/40/18 all around and it fixed the problem. I only used the car for town work while I was waiting for the correct tyres

[samuri]

I have never seen someone run wider tyres at the front. Interesting.

Basically though, the system can deal with something like a 2% variance in tyre size front to back so it can deal with uneven tyre wear.

Its not a problem to have the larger tyres at the back but I thought having the superior handling and better grip tyres at the front might be safer?so have 245 45R 18 on the front not 225 45R 18

also is there a legal component to this as I don't want to void my insurance

Also 2 % of 225 is 4.5. what figure are you refering to????????????

tyres already paid for and fitted on Friday. first time via internet so cant easily cancel

[samuri]

Personally I wouldn't, just run the same size tyres to protect your attessa clutch packs and driveshaft uni's.

Hi scotty

your exhaust modification on my car is great .

I don't understand comments at all about about attessa clutch packs about drive shaft unis.

Also how does damage occur ,what type of damage?is this damage catasro@pic or justminor additional wear

Would I know or somehow experience this damage?

Would like to sort this out before Friday,replacement day

thanks

[samuri]

Mr Brick above made the comment about 2 percent variation was ok.

But is that contrary to scottys opinion?

starting to get confused with possible conflicting information.

thanks everyone

[KiwiRS4T]

To be quite safe you should run the same tyres front and rear although small differences will occur anyway as tyres wear.

It is the rolling circumference that matters not the width.

The aspect ratio (the 45 in your tyre size) is not the height of the tyre - it is the height expressed as a percentage of the width so if you have different widths you will also have different heights which can make a significant difference to your rolling circumference. This can result in damage to the atessa (google for the long explanation). The damage in the long term can be serious in the short term it can make for unwelcome vibrations and shuddering.

If you haven't already got the tyres you may be able to get the figures from the makers specs but really you are better off to run the same tyres front and rear.

[scotty nm35]

Hi scotty

your exhaust modification on my car is great .

I don't understand comments at all about about attessa clutch packs about drive shaft unis.

Also how does damage occur ,what type of damage?is this damage catasro@pic or justminor additional wear

Would I know or somehow experience this damage?

Would like to sort this out before Friday,replacement day

thanks

Bob is on the money, just get a full set of whatever tire you are buying, even if it means getting a cheaper option. I have changed enough front tailshafts to know they are prone to wear without this extra unwanted vibration and loading, there is no give in the Attessa system, (there is no centre diff), just a clutch pack that binds the two axles together essentially. Something has to give and long term it will be the front uni due to it's small size.

The other option is to drop the front shaft for now and drive in RWD until you can buy the other pair.

[Daleo]

It's been my experience that the AWD gets upset with a very small amount of variance.

I had 2 worn tyres (rear), and 2 brand new tyres (front) and above 80kmh the Attessa was extremely active, and very unhappy indeed.

Drop the front shaft if you want to run that tyre combination.

[samuri]

advice heeded guys . thanks

have ordered a further 2 tyres 24518 r 45

but I have to drive 3 kilometres to Tyre shop on front and back mismatch sizes.

What sort of distance is unacceptable?

Also 45/225 and 45/245, the difference is 1.6 percent

which is apparently acceptable according to a prior post. is that true

Edited February 9, 2016 by samuri

[nickcorr]

2.7% according to my calculations... So should be okay over 3km, but take it easy....

You might also want to drive around with a speedo app open for a while as well, because with the 245/45R18s on vs. the 225/45R18s, you will be going that little bit further for each rotation. So your speedo will also be another 2.7% wrong as well...

But enjoy the new tyres... I ran Eagle F1 directionals on my ARX and loved them

[Brick]

2.7% according to my calculations... So should be okay over 3km, but take it easy....

You might also want to drive around with a speedo app open for a while as well, because with the 245/45R18s on vs. the 225/45R18s, you will be going that little bit further for each rotation. So your speedo will also be another 2.7% wrong as well...

But enjoy the new tyres... I ran Eagle F1 directionals on my ARX and loved them

For such a short distance it should be ok. Take it very easy with no rapid acceleration and it will be ok.

The 245/45 will actually bring the speedo more into an accurate number

[Jetwreck]

I tried running the 19" Rays from the V35's on mine. was about 3-4% out and it was absolutely horrible. I even went to the extent of sorting new tyres on the front to the closest rolling diameter.....it was a fail.

[Philr32]

I've seen people running 1" wider rims on the rear but same size tyres front and back which they say they have had no issues with. I guess that's not entirely relevant for this post but some extra info on a similar topic.

[datmoo]

Did some calculations when I was looking at tyres when going from my stock 17's to 18's.

Total diameters:

235/45 17" 537.55mm ⍉

225/45 18" 558.45mm ⍉

235/40 18" 551.20mm ⍉

235/45 18" 562.95mm ⍉

235/50 18" 574.70mm ⍉

245/40 18" 555.20mm ⍉

245/45 18" 567.45mm ⍉

Went with 235/45, sits nice and flush on 8.5" wide rims and makes the speedo more accurate.