Tyre pressures and ultra low-profile tyres

[Ext User(Jason James)]

After having a couple of tyres replaced, the fitters did their usual thing
and pumped them all to 37 psi (hot). Made for a much harder ride on the '95
Camry I use for general duties. I hadn't got around to setting them too
28-30psi when coming back from Sydney, and my back started to complain about
the shocks transmitted thru the suspension. So I dropped them back and the
extra cushioning was immediately evident.

I've often wondered about the ultra low-profile tyres on many vehicles
to-day, and how because of their low wall-height, they must be run at much
higher pressures to simply stop damage. Is this so, or does the extra width
allow lower pressures (eg 30 psi)? Do those with stuffed backs etc find this
a problem with modern large diameter rims?

[Ext User(PHATRS)]

Jason James wrote:
> After having a couple of tyres replaced, the fitters did their usual thing
> and pumped them all to 37 psi (hot). Made for a much harder ride on the '95
> Camry I use for general duties. I hadn't got around to setting them too
> 28-30psi when coming back from Sydney, and my back started to complain about
> the shocks transmitted thru the suspension. So I dropped them back and the
> extra cushioning was immediately evident.
>
> I've often wondered about the ultra low-profile tyres on many vehicles
> to-day, and how because of their low wall-height, they must be run at much
> higher pressures to simply stop damage. Is this so, or does the extra width
> allow lower pressures (eg 30 psi)? Do those with stuffed backs etc find this
> a problem with modern large diameter rims?
>
>

I have 18 inch rims and 45 profile tyres. Pressure is still no more than
40psi. I could run as low as 34 on the fronts according to factory specs
but the grip and steering feel is noticably better around 38-40psi.

I used to run a similar pressure in 50 profile tyres on 16 inch wheels.

No idea how I would cope with a stuffed back.

Ben

[Ext User(Jason James)]

"PHATRS" <nosp@m.thanks.mate> wrote in message
news:1hkao4-j7s.ln1@teri.unico.com.au...
> Jason James wrote:
> > After having a couple of tyres replaced, the fitters did their usual
thing
> > and pumped them all to 37 psi (hot). Made for a much harder ride on the
'95
> > Camry I use for general duties. I hadn't got around to setting them too
> > 28-30psi when coming back from Sydney, and my back started to complain
about
> > the shocks transmitted thru the suspension. So I dropped them back and
the
> > extra cushioning was immediately evident.
> >
> > I've often wondered about the ultra low-profile tyres on many vehicles
> > to-day, and how because of their low wall-height, they must be run at
much
> > higher pressures to simply stop damage. Is this so, or does the extra
width
> > allow lower pressures (eg 30 psi)? Do those with stuffed backs etc find
this
> > a problem with modern large diameter rims?
> >
> >
>
> I have 18 inch rims and 45 profile tyres. Pressure is still no more than
> 40psi. I could run as low as 34 on the fronts according to factory specs
> but the grip and steering feel is noticably better around 38-40psi.
>
> I used to run a similar pressure in 50 profile tyres on 16 inch wheels.
>
> No idea how I would cope with a stuffed back.

I wonder if they run softer spring rates to compensate on cars that have
these tyres fitted standard?

Jason

[Ext User(a t e c 7 7)]

Jason James wrote:
> "PHATRS" <nosp@m.thanks.mate> wrote in message
> news:1hkao4-j7s.ln1@teri.unico.com.au...
>> Jason James wrote:
>>> After having a couple of tyres replaced, the fitters did their usual
> thing
>>> and pumped them all to 37 psi (hot). Made for a much harder ride on the
> '95
>>> Camry I use for general duties. I hadn't got around to setting them too
>>> 28-30psi when coming back from Sydney, and my back started to complain
> about
>>> the shocks transmitted thru the suspension. So I dropped them back and
> the
>>> extra cushioning was immediately evident.
>>>
>>> I've often wondered about the ultra low-profile tyres on many vehicles
>>> to-day, and how because of their low wall-height, they must be run at
> much
>>> higher pressures to simply stop damage. Is this so, or does the extra
> width
>>> allow lower pressures (eg 30 psi)? Do those with stuffed backs etc find
> this
>>> a problem with modern large diameter rims?
>>>
>>>
>> I have 18 inch rims and 45 profile tyres. Pressure is still no more than
>> 40psi. I could run as low as 34 on the fronts according to factory specs
>> but the grip and steering feel is noticably better around 38-40psi.
>>
>> I used to run a similar pressure in 50 profile tyres on 16 inch wheels.
>>
>> No idea how I would cope with a stuffed back.
>
> I wonder if they run softer spring rates to compensate on cars that have
> these tyres fitted standard?
>
> Jason
>
>
I parked this morning beside a newish yankee Lux on a set of 20"

damn they are tall wheels

[Ext User(Marco)]

On Aug 3, 6:43 am, "Jason James" <a...@peace.com> wrote:
>
> I've often wondered about the ultra low-profile tyres on many vehicles
> to-day, and how because of their low wall-height, they must be run at much
> higher pressures to simply stop damage. Is this so, or does the extra width
> allow lower pressures (eg 30 psi)? Do those with stuffed backs etc find this
> a problem with modern large diameter rims?

The VE is set at 36psi all round (even those on 16 inch wheels with
high profile tyres). It's actually not too bad, I expected it to be
much harsher but I think Holden has done some work on bushes and so on
to still allow for a fairly comfortable ride. Mine's on 18 inch rims
with 245/45 series tyres and it's not bad at all. Having said that, I
don't have back problems or anything like that.

When the dealer reset the pressures at 32psi at the 3000km service
(why I don't know), the difference in steering feel and general
'vagueness' in the handling was very obvious.

Marco

[Ext User(Jason James)]

"a t e c 7 7" <"atec 77 at hotmail dot com"> wrote in message
news:46b2ae73$1@dnews.tpgi.com.au...
> Jason James wrote:
> > "PHATRS" <nosp@m.thanks.mate> wrote in message
> > news:1hkao4-j7s.ln1@teri.unico.com.au...
> >> Jason James wrote:
> >>> After having a couple of tyres replaced, the fitters did their usual
> > thing
> >>> and pumped them all to 37 psi (hot). Made for a much harder ride on
the
> > '95
> >>> Camry I use for general duties. I hadn't got around to setting them
too
> >>> 28-30psi when coming back from Sydney, and my back started to complain
> > about
> >>> the shocks transmitted thru the suspension. So I dropped them back and
> > the
> >>> extra cushioning was immediately evident.
> >>>
> >>> I've often wondered about the ultra low-profile tyres on many vehicles
> >>> to-day, and how because of their low wall-height, they must be run at
> > much
> >>> higher pressures to simply stop damage. Is this so, or does the extra
> > width
> >>> allow lower pressures (eg 30 psi)? Do those with stuffed backs etc
find
> > this
> >>> a problem with modern large diameter rims?
> >>>
> >>>
> >> I have 18 inch rims and 45 profile tyres. Pressure is still no more
than
> >> 40psi. I could run as low as 34 on the fronts according to factory
specs
> >> but the grip and steering feel is noticably better around 38-40psi.
> >>
> >> I used to run a similar pressure in 50 profile tyres on 16 inch wheels.
> >>
> >> No idea how I would cope with a stuffed back.
> >
> > I wonder if they run softer spring rates to compensate on cars that have
> > these tyres fitted standard?
> >
> > Jason
> >
> >
> I parked this morning beside a newish yankee Lux on a set of 20"
>
> damn they are tall wheels

Depending on the car, suspension height, once they get too large, they look
shithouse. The bright chrome Ninja-stars look crap any size.

Jason

[Ext User(Noddy)]

"PHATRS" <nosp@m.thanks.mate> wrote in message
news:1hkao4-j7s.ln1@teri.unico.com.au...

> I have 18 inch rims and 45 profile tyres. Pressure is still no more than
> 40psi. I could run as low as 34 on the fronts according to factory specs
> but the grip and steering feel is noticably better around 38-40psi.

Jeez...

I'm glad I don't tide around in your car. Fred Flinstone's heap of shit
would have been more comfortable.

--
Regards,
Noddy.

[Ext User(Daryl Walford)]

Jason James wrote:
> After having a couple of tyres replaced, the fitters did their usual thing
> and pumped them all to 37 psi (hot). Made for a much harder ride on the '95
> Camry I use for general duties. I hadn't got around to setting them too
> 28-30psi when coming back from Sydney, and my back started to complain about
> the shocks transmitted thru the suspension. So I dropped them back and the
> extra cushioning was immediately evident.
>
> I've often wondered about the ultra low-profile tyres on many vehicles
> to-day, and how because of their low wall-height, they must be run at much
> higher pressures to simply stop damage. Is this so, or does the extra width
> allow lower pressures (eg 30 psi)? Do those with stuffed backs etc find this
> a problem with modern large diameter rims?
>
>
The stock tyres on our Subaru are low profile, 45's I think and the ride
is firm but not uncomfortable.
I haven't checked them for a while but I run them at 32psi which is what
the dealer recommended.
If your back plays up in a Camry with 37 in the tyres I recommend you
don't ride in a 4WD Hilux with 40 psi in light truck tyres:-)


Daryl

[Ext User(Jason James)]

"Kev" <kevcat@optunet.com.au> wrote in message
news:46b39027$0$19339$afc38c87@news.optusnet.com.a u...
> Daryl Walford wrote:
> > Jason James wrote:
> >> After having a couple of tyres replaced, the fitters did their usual
> >> thing
> >> and pumped them all to 37 psi (hot). Made for a much harder ride on
> >> the '95
> >> Camry I use for general duties. I hadn't got around to setting them too
> >> 28-30psi when coming back from Sydney, and my back started to complain
> >> about
> >> the shocks transmitted thru the suspension. So I dropped them back and
> >> the
> >> extra cushioning was immediately evident.
> >>
> >> I've often wondered about the ultra low-profile tyres on many vehicles
> >> to-day, and how because of their low wall-height, they must be run at
> >> much
> >> higher pressures to simply stop damage. Is this so, or does the extra
> >> width
> >> allow lower pressures (eg 30 psi)? Do those with stuffed backs etc
> >> find this
> >> a problem with modern large diameter rims?
> >>
> >>
> > The stock tyres on our Subaru are low profile, 45's I think and the ride
> > is firm but not uncomfortable.
> > I haven't checked them for a while but I run them at 32psi which is what
> > the dealer recommended.
> > If your back plays up in a Camry with 37 in the tyres I recommend you
> > don't ride in a 4WD Hilux with 40 psi in light truck tyres:-)
> >
> >
> > Daryl
>
>
> I've been running 38psi on the ford as recommended by the fitter,
> apparently it has something to do with keeping the centre of the tyre in
> contact with the road otherwise the shoulders of the tyres wear out and
> the centre tread dosen't

Its a problem. The Ford runs 8" wide rims on the front with 225/65/14s and
if I keep them at 28 psi the outside shoulders start to wear faster than the
rest of the tread.

Jason

[Ext User(Jason James)]

"Marco" <ignition.vess@gmail.com> wrote in message
news:1186115751.207028.187300@d30g2000prg.googlegr oups.com...
> On Aug 3, 6:43 am, "Jason James" <a...@peace.com> wrote:
> >
> > I've often wondered about the ultra low-profile tyres on many vehicles
> > to-day, and how because of their low wall-height, they must be run at
much
> > higher pressures to simply stop damage. Is this so, or does the extra
width
> > allow lower pressures (eg 30 psi)? Do those with stuffed backs etc find
this
> > a problem with modern large diameter rims?
>
> The VE is set at 36psi all round (even those on 16 inch wheels with
> high profile tyres). It's actually not too bad, I expected it to be
> much harsher but I think Holden has done some work on bushes and so on
> to still allow for a fairly comfortable ride. Mine's on 18 inch rims
> with 245/45 series tyres and it's not bad at all. Having said that, I
> don't have back problems or anything like that.
>
> When the dealer reset the pressures at 32psi at the 3000km service
> (why I don't know), the difference in steering feel and general
> 'vagueness' in the handling was very obvious.

Maybe it has something to do with the reduced air-mass.

Jason

[Ext User(Jason James)]

"Daryl Walford" <dwalford@internode.on.net> wrote in message
news:13b5l1br5t0eo14@corp.supernews.com...
> Jason James wrote:
> > After having a couple of tyres replaced, the fitters did their usual
thing
> > and pumped them all to 37 psi (hot). Made for a much harder ride on the
'95
> > Camry I use for general duties. I hadn't got around to setting them too
> > 28-30psi when coming back from Sydney, and my back started to complain
about
> > the shocks transmitted thru the suspension. So I dropped them back and
the
> > extra cushioning was immediately evident.
> >
> > I've often wondered about the ultra low-profile tyres on many vehicles
> > to-day, and how because of their low wall-height, they must be run at
much
> > higher pressures to simply stop damage. Is this so, or does the extra
width
> > allow lower pressures (eg 30 psi)? Do those with stuffed backs etc find
this
> > a problem with modern large diameter rims?
> >
> >
> The stock tyres on our Subaru are low profile, 45's I think and the ride
> is firm but not uncomfortable.
> I haven't checked them for a while but I run them at 32psi which is what
> the dealer recommended.
> If your back plays up in a Camry with 37 in the tyres I recommend you
> don't ride in a 4WD Hilux with 40 psi in light truck tyres:-)

Its been a while since I could drive a 4WD any great distance.

Jason

[Ext User(Legoman)]

On Fri, 03 Aug 2007 03:40:03 GMT, PHATRS <nosp@m.thanks.mate> wrote:

>Jason James wrote:
>> After having a couple of tyres replaced, the fitters did their usual thing
>> and pumped them all to 37 psi (hot). Made for a much harder ride on the '95
>> Camry I use for general duties. I hadn't got around to setting them too
>> 28-30psi when coming back from Sydney, and my back started to complain about
>> the shocks transmitted thru the suspension. So I dropped them back and the
>> extra cushioning was immediately evident.
>>
>> I've often wondered about the ultra low-profile tyres on many vehicles
>> to-day, and how because of their low wall-height, they must be run at much
>> higher pressures to simply stop damage. Is this so, or does the extra width
>> allow lower pressures (eg 30 psi)? Do those with stuffed backs etc find this
>> a problem with modern large diameter rims?
>>
>>
>
>I have 18 inch rims and 45 profile tyres. Pressure is still no more than
>40psi. I could run as low as 34 on the fronts according to factory specs
>but the grip and steering feel is noticably better around 38-40psi.
>
>I used to run a similar pressure in 50 profile tyres on 16 inch wheels.
>
>No idea how I would cope with a stuffed back.

Keep driving around on tyres pumped up to 40psi and you will know soon
enough.

[Ext User(Legoman)]

On Fri, 3 Aug 2007 16:07:06 +1000, "Noddy" <dg4163@(nospam)dodo.com.au>
wrote:

>
>"PHATRS" <nosp@m.thanks.mate> wrote in message
>news:1hkao4-j7s.ln1@teri.unico.com.au...
>
>> I have 18 inch rims and 45 profile tyres. Pressure is still no more than
>> 40psi. I could run as low as 34 on the fronts according to factory specs
>> but the grip and steering feel is noticably better around 38-40psi.
>
>Jeez...
>
>I'm glad I don't tide around in your car. Fred Flinstone's heap of shit
>would have been more comfortable.

Tyre pressure is the new wank factor thing to get for that fully sik
street-cred d00d! Don't you know anything? If you're not running at least
the tyre's maximum inflation pressure then you're not bad-ass and the hawt
chicks won't talk to you after you've done those fully-sik burnouts in the
Maccas carpark at 3 in the morning.

I'm betting these 18" 45 series tyres at 40 psi were on a totally bitchin'
Hyundai Excel too.

Werd up to yo mutha! Fully sik.