Overinflated tyres? They're a manufacturers recommendation!

[Yugguy]

Got an Insignia hire car for work for a week. Messing about with the computer I notice it's got tyre pressure monitors and they're reading 44psi all round. I think blimey, so I get my gauge out and it's right. So I look on the door jamb for the pressure sticker and on there it states that normally it should be 32, 30, but for economy 44 all round.

Now I'd always understood that over-inflation reduces grip and wears out the centre of the tyre. I'm all for saving fuel bills but not at the expense of those.

Very odd.

 

[pgarner]

i can understand how it works through the less grip, less rolling resistance but im sure the cost of 4 tyres earlier is going to be more than whats been saved

 

[MickieH]

Bit dodgy that.

Did you have a look at the tread on the tyres as they're obviously running it like that normally?

Not something I'd try, I prefer grip and safety to economy any day.

 

[HDi fun]

44 seems very high. Slight over-inflation is generally good for tyre life as it reduces sidewall flexing and therefore reduces heat build up. The only downside is a slightly harsher ride. But I'm thinking of 10% max.

28 PSI to 44 psi sounds a bit suspect. You're likely to just wear out a central band of tread and have tiptoe handling and grip.

 

[obi_waynne]

It could be a mis print I suppose, did they mean 34 psi?

 

[geraint13]

i keep mine on 36psi. Max is 44psi written on the tyre

 

[Yugguy]

Doubt it's a misprint, might be I guess. I let them down to 32, 30.

 

[HDi fun]

i keep mine on 36psi. Max is 44psi written on the tyre

The 44 on the tyre is a maximum safe pressure and has nothing to do with the correct pressure for the intended application.

 

[turbonutter69]

I think I know why it's got 44psi in.

Got an Insignia hire car for work for a week. Messing about with the computer I notice it's got tyre pressure monitors and they're reading 44psi all round. I think blimey, so I get my gauge out and it's right. So I look on the door jamb for the pressure sticker and on there it states that normally it should be 32, 30, but for economy 44 all round.

Now I'd always understood that over-inflation reduces grip and wears out the centre of the tyre. I'm all for saving fuel bills but not at the expense of those.

Very odd.

 

[HDi fun]

I think I know why it's got 44psi in.

Go on - enlighten us.

 

[turbonutter69]

Nitrogen filled.

 

[HDi fun]

Nitrogen filled.

That wouldn't account for it. Earth's atmosphere is nearly 80% nitrogen anyway.

 

[turbonutter69]

That wouldn't account for it. Earth's atmosphere is nearly 80% nitrogen anyway.

Well my Focus has Nitrogen filled tyres now and when I checked them the other week they was exactly the same. 44psi. Usual pressure is 31psi.
Could be the reason you never know.
Next time I have a tyre fitted i'll ask.

 

[HDi fun]

Did you check them cold or after use?

 

[turbonutter69]

Cold buddy. Never bothered checking them after use.
I only checked them cause one looked squashy.

 

[HDi fun]

I'm struggling to see how nitrogen inflation can cause such a disparity.

 

[turbonutter69]

Me too. Like I said i'll ask next time I have a tyre fitted. It won't be long i'm sure i'm about due another puncture.:sad2:

 

[HDi fun]

Me too. Like I said i'll ask next time I have a tyre fitted. It won't be long i'm sure i'm about due another puncture.:sad2:

I went though a phase of replacing tyres incessantly because of a small bunch of careless contractors who dropped stuff in the road locally to here.

The worst case was early 2008 where I replaced FOUR in the space of a month due to punctures and all were less than 200 miles old.

I resent that, to be honest. Decent tyres are not cheap.

 

[turbonutter69]

I've had it like that. I had one tyre on the other month for about three days. Puncture was in the sidewall so couldn't be repaired.
Mind you saying that I don't have any repaired they get straight replaced.
I've been through four tyre's this year alone due to punctures.:sad2:

 

[HDi fun]

I'm fussy about tyres, too. But if the damage is in the tread area, not adjacent to shoulders and not in the sidewall then a repair is fine for a simple puncture.

any tearing of the rubber or carcass and it has to be chucked.

 

[turbonutter69]

They get replaced anyway regardless of what I think.
My only problem is I ran them out of Michelin Primacy's so now I have a mixed front end of Conti and a Bridgestone. Both are a grippy tyre but I feel they are little short on the Primacy's.
When I get my backside into gear i'm swapping them over for the two on the rear which are Primacy's.

 

[HDi fun]

Mixing across the axle can cause all sorts of issues. Best to do as you say, commit to a particular tyre and stick with it.

 

[turbonutter69]

If I could of I would of had them replaced with the Primacy's but I couldn't. They aren't bad I mean it's still on rails through the bends but I felt more confidence in the Primacy's.

 

[HDi fun]

You've been fond of these for ages and I'm considering fitting them to the BMW once the current set wears down a bit. Primacy HP I think is the fitment for my car.

 

[turbonutter69]

They are great on the Focus I can't fault them at all tbh.