Tyre question - I know, done to death, still ...

[jnwright71]

Hi All,

Help please. My Z (2.5s.i roadster) has Pirelli P Zero Rosso 225/40 R18 92Y XL on the front and Pirelli P Zero 255/35 R18 94Y XL on the rear. The car tramlines, ride and directional control is twitchy and at high speed the car just feels dangerous.

I have had all the suspension checked, new lollipop bushes (Meyle HD) fitted and full alignment done.

I am now considering changing the tyres before I give up and buy a Boxster instead So, advice please. Lots recommend Goodyear Eagle F1 Ass 2s but don't state whether these are the XL or standard load versions (I have read XL tyres can increase tramlining) ? Also, should I stick with the original 88 weight rating or go for 92 ? Bizarrely, the non XL 88Y Goodyear is 30% more expensive than the higher rated 902Y XL version !!

Thoughts please .... Ta

 

[paulgs1000]

It might be stating the obvious but

have you tried different tyre pressures? I've found just 2psi can make a big difference. I have GOOD YEAR F1s at 32 front 34 rear after experimenting.

Also how much tread do you have on the tyres? I find getting down past 4mm to 3mm or thereabouts the tyres start to feel poor again.

My Zed still tramlines and can be twitchy but this is greatly reduced by fitting non runflats and it feels part of the character of the Zed now.

I'm surprised you are still having problems with all the checks and setting up you've done.

Hope you get sorted.

 

[jnwright71]

Hi Paul,

Thanks for your reply. I have checked and played with tyre pressures. I am currently running 29F, 32R as anything above this makes the issue worse. Are your GY F1s XL or non XL ? and 88Y 0r 92Y ?

Thx.

 

[paulgs1000]

Just checked, 92Y and XL - extra load (which does seem ridiculous given a relatively light sports car - I didn't see any other option though when I bought my tyres. Have you found another version of the GOOD YEAR F1s?)

I had Falkans fitted before the GOOD YEARS and I had a long chat to their main office over best fitment. Perhaps you could Google Pirelli or GOOD YEAR UK and see if anyone could advise about the XL?

If you get any results or comments I'd be interested to hear. . . .

 

[jnwright71]

Spoke to GOODYEAR technical who recommended sticking with the 88W spec, but then confirmed that only run flats are available as an 88Y spec. The Goodyear website recommends this, Efficient Grip Performance 92Y XL or Excellence 92Y XL - so that is as clear as mud !!

www.tyreleader.co.uk lists an 88Y non run flat version, but Goodyear don't !! Confused.

Are there any members local to Peterborough who would be kind enough to lend me a set of 18 inch fronts to test (and prove tyres are the issue) before I shell out on new rubber ?

thx

 

[hopz121]

I run 34 Front and 36 Rear on my GY AS2 non run flats

Another thing worth trying is RTAB, my car was a bit like this and i had done the above like yourself, i had powerflex bushes fitted to the RTAB and hey presto car drives great

I would say this is my best mod to date and suggest trying that first before giving up

I paid around £160 fitted all in and cant get over how much difference it has made to the way the car drives

 

[jnwright71]

hi Hopz121,

Thanks for the reply. Did you have any play in the RTAB s ? And did they fit shims as well to minimise movement and future wear ?

Will definitely get these checked.

Thx

 

[Dewi]

I've just ordered Eagle F1s for my car - also a 2.5si - I could get the fronts in the original spec but not the rears so opted for XL all round. They're not being fitted 'til Monday but I'll let you know what if any difference the Good Years make. My car tramlines but it's not terrible, I've learned to live with it. Apart from that the handling is very good - always seems very planted pushing into bends and the tyres are still the originals - coming up to 10 years old now.

I put XLs on my old 1.8 MX5 to replace the original 84W Potenzas (as opposed to the 2.0 litre I had afterwards which had abysmal handling). The 1.8 was fitted with Conti Sport 3s and the extra loading made no difference to the ride at all after a few hundred miles had scrubbed them up.

 

[jnwright71]

Hi Dewi,

Did you get the Goodyear's fitted ? If so, how are you finding them ?

Cheers, James

 

[Dewi]

Hi, James, sorry for delayed replay been out tonight for my wife's birthday.

Yes, I had the GYs fitted on Monday, I did actually mention on another thread here but it wasn't well read and kind of fell down the pecking order of things. The new Good Year Eagle F1s are 92Y-F & 94Y-R and have made an incredible difference to the feel of the car. There's no more tramlining or having the wheel pulled from my hands going over potholes. It's only now I realise how bad it was - I had kind of got used to it. I took it out on the M/way for the first time today and it's rock solid - let go of the wheel and the car goes dead straight at 80mph, nothing seems to upset it. Despite the stiffer sidewalls (which are still softer than the run flats) the ride is a tad more comfy. This is now what I bought a Z4 for.

All I can say is that the cost of these tyres are money well spent - £518 fitted at my house. I checked the manufactured date before the guy started fittng them, fronts are late 2014 and rears early 2015 and both pairs have the rim protector rib. For anyone debating what tyres to get, seriously consider the GYs, they are really very very good. I'm a convert.

 

[jnwright71]

Hi Dewi,

Great news, thanks. I shall start getting some pennies together ans switch to these ASAP.

Cheers, James

 

[hopz121]

hi Hopz121,

Thanks for the reply. Did you have any play in the RTAB s ? And did they fit shims as well to minimise movement and future wear ?

Will definitely get these checked.

Thx

Hi mate, sorry missed this reply,

There was no play in the originals apparently but they were looking tired and had 100k on them, the uprated bushes have stiffened up the rear alot though and stop alot of unwanted movement and has made the car drive alot better.

No shims as they are no required on aftermarket polybushes.

Ash

 

[Jollyjoiner]

I added to a thread the other day about tyres, I've now got Kumhos all round and the car drives fine, and much smoother over the bumps