i cant seem to find a definitive pressure i should pump my tyres up to. the back of the car has been feeling a bit loose round corners recently and i think its cause the pressures are a bit low. i drive a 1999 sporting so it has the smaller wheels than the abarth. i mean to upgrade to the wheels sometime but dont have the cash right now.

thanks

Somewhere between 30 and 32 psi, front and rear will be in the ballpark.

If you don't like how it feels try lowering the tyre pressure and see if that helps, if it does lower it a bit more, if it doesn't then put a little more pressure in than you had originally. Just feel around like that, eventually you'll find a pressure that if you go up or down from it gets worse, that's the tyre pressure for ideal handling.

The other way is to do the same but with tread depth, this may or may not end up giving the same tyre pressures.

Vech Hand book for '98 sporting says
for 165-55R13
cold
medium load
front 2.1
rear 2.0
full load
front 2.3
rear 2.3
spare
2.8

remeber that's bar not psi

Ming

Handling also depends on the age of the tyre. Sidewalls can lose their rigidity, so even if the pressure is right, the tyre flexes more than it did.

Cheers

SPD

Hi Ming

x 14.5

Noel

x 14.5037738

cheers

The pedant

rallycinq said:

Handling also depends on the age of the tyre. Sidewalls can lose their rigidity, so even if the pressure is right, the tyre flexes more than it did.

Cheers

SPD

Click to expand...

Hi David
You said the rear metal elastics will pass a MoT even when they are in a terrible state, that would not help handling either?
Noel

rallycinq said:

x 14.5037738

cheers

The pedant

Click to expand...

Hi

No 'David the tease' the tyre gauge even if it is digital wont show that many digits?

Noel

told already at "cheap tyre choice" topic, iam inflating to 2.6bar F/R and back is pretty nervous at cornering and breaking is making it worse-i think this is supsension cause not tyres

Hi

2.6 is a little high

The police in UK can check inflation in the UK, especially after an accident.

Have you tried the recommended pressure, braking distance in wet must be better softer?

Noel

you wouldnt exceed max pressure written on tyre(3 bar)
police cant threat you if ullhave 2.6-i think its normal to inflate to 2.6 when heavy loaded, or driving high speeds for long period of time

high pressure will lead to worn middle tread, but xr611s are mostly worn on outside, this could help it

Hi

I understand the logic but, your outside wear is either

- you are cornering to fast
- or have wheel tracking or other suspension problems

If you are cornering too fast then the increased tyre pressure will only have a marginal effect on the outside wear, it will only wear the middle when you are accelerating or braking in a straight line.

2.6 is more then the full load pressure recommended by Fiat for your tyre configuration.

In the wet the tyre foot print on the ground will be reduced by the increased pressure with a greater tendancy to aquaplane, if you aquaplane a tyre you dont have any control.

Noel

I usually run 2.2Bar Front & Rear.

Pep0 said:

Hi David
You said the rear metal elastics will pass a MoT even when they are in a terrible state, that would not help handling either?
Noel

Click to expand...

Not quite 'terrible state' but they can pass when worn beyond normal.

See benjammo's post recently.

Cheers

SPD

Pep0 said:

Hi

2.6 is a little high

The police in UK can check inflation in the UK, especially after an accident.

Click to expand...

I'm in trouble then, I'm on 195/40R14 tyres with 36psi (2.5) front, 32psi (2.2) rear as my nominal tyre pressure. I add an extra 2 to 3 psi in for heavy loads. Anything below 34/30psi and the car gets unpredictable, especially in the wet.

GoBe said:

I'm in trouble then, I'm on 195/40R14 tyres with 36psi (2.5) front, 32psi (2.2) rear as my nominal tyre pressure. I add an extra 2 to 3 psi in for heavy loads. Anything below 34/30psi and the car gets unpredictable, especially in the wet.

Click to expand...

Well I'd plead two excuses

a) I'm going to pick up a heave load, and I wanted to get the pressures right cold
b) wide tyres, but Ive told my ins company

the front rear asymetry will help the understeer handling, worth while saying that too, normally the police are nice to me, saying things that imply you know what a black round thing does reassures them a lot.

But if you are upside down on grass they can be excessively curious.

And I understand the handling problems I frequently have to find rosary beads part way through corners that tighten up, especially in wet, when the understeer leaves no other options. My OEM tyre size and model is terrible in wet and rubber deposit conditions, ditto ice.

Noel
P.S. your footprint is not going to be good in standing water, you need to discard before 1.6mm for sure

rallycinq said:

Not quite 'terrible state' but they can pass when worn beyond normal.

See benjammo's post recently.

Cheers

SPD

Click to expand...

mine passed when they were really bad, previous owner replaced the tyres cause of strange wear pattern but could not locate the noise source...

Noel

cool thanks for the help guys. i think the tyres are a bit old but have decent tread whic could be why they feel weird, but will look into getting some new good rubber on them. i did say i wanted the Abarth wheels and as there are loads of threads about sei abarth drivers changing wheels does anyone have a set of abarth wheels they would wanna sell?