Tyre Advice - car doesn't feel right

[sunbeam_alpine]

I have spent the last 6 months tidying up an Alfa Spider, and it is now back on the road.

I'm planning to replace the tyres - they are at least 10 years old!!

I've done a few runs, both on normal roads and motorways, and the car feels what I can best describe as 'wandery', not planted on the road, and practically no feed-back.

I used to have an identical car which handled much better. The old one had (I think) 195/60/15 tyres. This one has 205/55/15 tyres (Pirelli 6000). These tyres are also giving the problem that the car is too low - speed bumps etc. have to be avoided. Luckily there are is a sump guard, which gets regular use!

So, before I go buy the new tyres, I'd like some independent advice on what is the best tyre size. I need to get the car a bit higher - it's very unnerving to drive - I can even ground out on the road if it's not very smooth.

Will 195/60/15 tyres cure the handling, or should I be looking at something else? (the car has just passed the Belgian equivalent of an MOT without any comments/criticism).

I'm hoping that someone can give me good advice here. My first Spider felt brilliant to drive, this one doesn't. It is the identical model - same year etc.

P.S. Mods - please don't move this to Alfa - my question is about tyres, not about the model.

[300bhp/ton]

doogz said:

The rolling radius of the 205's is 0.75mm larger than that of the 195's.

This is not what is causing you to hit speed bumps.

Nor is it likely to be causing the car to feel wandery. Sounds like you have some bushes somewhere wanting looked at, and the wheel alignment set up properly.

Although, it has to be said P6000's are truly dreadful tyres.

You sure about .75 of mm?

Also P6000's ain't that bad, not by a long shot.

[5lab]

what tire pressure are you running in there? If its overly high you'll get the symptoms you describe

alternitively, check for play in the bushings etc. if some of them are gone it'll add vagueness to the steering

[Gad-Westy]

300bhp/ton said:

doogz said:

The rolling radius of the 205's is 0.75mm larger than that of the 195's.

This is not what is causing you to hit speed bumps.

Nor is it likely to be causing the car to feel wandery. Sounds like you have some bushes somewhere wanting looked at, and the wheel alignment set up properly.

Although, it has to be said P6000's are truly dreadful tyres.

You sure about .75 of mm?

Also P6000's ain't that bad, not by a long shot.

Not sure about tyre size as haven't worked it out but its worth bearing in mind that there can be small differences anyway between different tyres even if they're the same 'official' size. And obviously if you wear 4mm of tread off, the car sits 4mm lower so that makes a difference too.

Have to concur with doogz though about P6000's. Maybe his wording was a little strong but they're not a good tyre. I would suggest that could account for the floaty feel on its own regardless of bushes etc..

[porka944s]

What pressures are you running at, in my 944 it felt like a boat for ages i always just put 30-32 psi no matter what car, suggested levels for the 944 are alot higher, after i did this it felt tight again.

[HellDiver]

I'd put some decent tyres on there, the P6000 (especially 10 year old ones) will be deathtraps. They do not work well on lighter cars at all.

[sunbeam_alpine]

5lab said:

what tire pressure are you running in there? If its overly high you'll get the symptoms you describe

alternitively, check for play in the bushings etc. if some of them are gone it'll add vagueness to the steering

Thanks for the replies so far. The tyre pressures are 2.2 bar. The car has just passed the equivalent of the MOT (I'm in Belgium), so surely they would identify wear in the steering?

Where could I go to get the steering checked out - garage or tyre place?

The problem is that the Alfa garages in this area aren't at all interested in working on older cars.

Edited to add - there were no advisories on the MOT

Edited by sunbeam_alpine on Tuesday 30th March 12:56

[Rawwr]

porka944s said:

i always just put 30-32 psi no matter what car

[sunbeam_alpine]

HellDiver said:

I'd put some decent tyres on there, the P6000 (especially 10 year old ones) will be deathtraps. They do not work well on lighter cars at all.

I'm planning to put new tyres on - that's why I asked the question. What I want to know is whether the tyre size was causing the handling problem so that I can buy the best size tyre for the car.

P.S. Any suggestions for the best size/make of tyre are welcome. Car is a 1990 Alfa Spider 2.0 injection. Driving is spirited cruising, not track days or really chucking it about.

[Munter]

Rawwr said:

porka944s said:

i always just put 30-32 psi no matter what car

I was thinking that! The MX5 runs 26psi standard. 30 and I'd need a new spine.

P6000s I don't like anyway. 10 year old P6000s (unless properly stored in an appropriate environment) are I'm guessing on the terrifying side of crap.

Get some nice new rubber on it in the correct "handbook" size. Set the pressures right. Then if it's still "off" take it for a full on laser 4 wheel alignment.

edit:big fan of dunlops at the moment for tyres. But I'll bet you can get goodyear f1 in the right size though which are a good bet.

Edited by Munter on Tuesday 30th March 13:01

[james_gt3rs]

10 years old!

Why leave it so long?!

[300bhp/ton]

sunbeam_alpine said:

I have spent the last 6 months tidying up an Alfa Spider, and it is now back on the road.

I'm planning to replace the tyres - they are at least 10 years old!!

I've done a few runs, both on normal roads and motorways, and the car feels what I can best describe as 'wandery', not planted on the road, and practically no feed-back.

I used to have an identical car which handled much better. The old one had (I think) 195/60/15 tyres. This one has 205/55/15 tyres (Pirelli 6000). These tyres are also giving the problem that the car is too low - speed bumps etc. have to be avoided. Luckily there are is a sump guard, which gets regular use!

So, before I go buy the new tyres, I'd like some independent advice on what is the best tyre size. I need to get the car a bit higher - it's very unnerving to drive - I can even ground out on the road if it's not very smooth.

Will 195/60/15 tyres cure the handling, or should I be looking at something else? (the car has just passed the Belgian equivalent of an MOT without any comments/criticism).

I'm hoping that someone can give me good advice here. My first Spider felt brilliant to drive, this one doesn't. It is the identical model - same year etc.

P.S. Mods - please don't move this to Alfa - my question is about tyres, not about the model.

Tyre's could be an issue, if they have gone a bit hard, warped and flat spotted they certainly could cause handling issues.

And if you want to change the tyre diameter they seem the obvious place to start.

However, if its that bad then I suspect there might be something else up. Might just be tracking/geo or it could be a bush or track rod end. Lastly maybe play in the steering simply making it feel far worse than it actually is.

Try the tyres first though.

As for size, well it depends.

A 195/55R15 has a side wall height of 117mm compared to 112.75mm for the 205/60's.

Overall it means the current tyres are 8.5mm shorter in diameter.

As for what is the right or best size, well its up to you. The rim width will limit the size ranges you can look at.

Generally wider tyres have a larger footprint and should offer more dry weather grip, they usually look chunkier and arguably better.

But are more likely to foul the body work or rub.

A taller side wall will allow more tyre roll under cornering. This helps produce a better ride, but also usually reduces the handling, although some suspension systems work quite well with higher profile tyres as they mean the rest of the suspension has less to deal with.

[jon-]

If you still have doubts about the P6000 read these two reviews about the P6000 on the Spider:

http://www.tyrereviews.co.uk/Tyres_For/Alfa-Romeo/...

As for replacements, if you don't want an obvious premium brand like a Goodyear or a Michelin I'd suggest looking at the Hankook Ventus V12 Evo, it's going very well at the moment in group tests: http://www.tyrereviews.co.uk/Article/2009-AMS-summ...

[HellDiver]

sunbeam_alpine said:

I'm planning to put new tyres on - that's why I asked the question. What I want to know is whether the tyre size was causing the handling problem so that I can buy the best size tyre for the car.

P.S. Any suggestions for the best size/make of tyre are welcome. Car is a 1990 Alfa Spider 2.0 injection. Driving is spirited cruising, not track days or really chucking it about.

My experience of the P6000 says they've got very flexible sidewalls, which will give you squishy handling.

Size is best going with the OE size, whatever that may be, assuming you have OE rims.

Finally, I'm a huge fan of the Bridgestone Turanza ER300. Good grip, pin sharp handling, and last well - I've seen 40k on the front of a Mk4 Astra out of a pair of ER300 (195-50-15).
I keep on trying other tyres and keep on ending up back with the ER300. Replaced Eagle F1-A with ER300 and handling was better on the ER300 than Goodyear's supposed "best" tyre.

They've done very well in recent tyre testing by the ADAC and AutoBild as well.

Edited by HellDiver on Tuesday 30th March 13:06

[munroman]

The Ford Explorer disaster in the US showed up that old tyres could delaminate even if unused.
I think 6 years was the figure recommended to change them at.
Also, the rubber will have lost oils and hardened, neither of which help grip.

It could be that the tyres feel bad because they are coming apart internally, so any movement on the ground isn't being fed through to the steering wheel properly.

Time for new tyres!

[300bhp/ton]

Gad-Westy said:

Have to concur with doogz though about P6000's. Maybe his wording was a little strong but they're not a good tyre. I would suggest that could account for the floaty feel on its own regardless of bushes etc..

P600's and I'd agree.

I know this tyre splits opinion, but I've only had good experience with the P6000's. On an XJ12 6.0, XJ-S V12 and there's a pair on the back of Roadster at the mo, which in all honesty seem to grip better than the Bridgestones on the front.

[Mr Gearchange]

Another vote for p6000's playing a major part - they are near useless on lighter cars.

My Puma came with P6000's as OE - when the front one's died I swapped them for BF Goodrich's - the net result was that the car tried to swap ends on every wet roundabout at pedestrian speeds.

They give awful feel, crap turn in and are like having blocks of soap on all four corners in the wet.

[sunbeam_alpine]

Thanks for all the replies!

In answer to some of them -

Why they are 10 years old - I only bought the car last year, it wasn't on the road (had been garaged for a few years), and I've only just finished tidying it up and getting it MOT'd.

The wheels are the standard Alfa ones (same as on my old spider), which had the 195's, so I guess that 195's should fit.

I'm not looking for the cheapest, but the best option.

Edit: I wish I knew what tyres my old spider had - I'd go for the same. I don't want to spend the money and get it wrong.

Edited by sunbeam_alpine on Tuesday 30th March 13:16

[300bhp/ton]

Mr Gearchange said:

Another vote for p6000's playing a major part - they are near useless on lighter cars.

My Puma came with P6000's as OE - when the front one's died I swapped them for BF Goodrich's - the net result was that the car tried to swap ends on every wet roundabout at pedestrian speeds.

They give awful feel, crap turn in and are like having blocks of soap on all four corners in the wet.

If they were OEM fit don't you think Ford would have tested them? And how would the Puma have gained a great reputation for handling (in stock OEM trim) if they were even half as bad as you claim?

Are you sure it wasn't more the fact that they were old and worn and you replaced them with new tyres which weren't worn and old?

[Mr Gearchange]

No because I did a like for like replacement onto brand new P6000's the first time. They are a poor tyre - why do you think they have the reputation that they do?

Their wet weather performance is utterly dire - just epic amounts of understeer when you got close to bothering the throttle. When I put Goodrich's on the front the back was scarily (and I do mean properly scarily) mobile and the tyres had a lot of tread left in them.

Yes the puma is a great handling car - despite it's st OEM tyres - but when you can combine that handling with improved grip it makes for a much better drive as you can actually get much more performance out of the car.