Tyre pressure

[Alex]

I wonder if anyone knows the answer to this.....
My 2000 has 15" wheels fitted,with195 tyres and I wonder how I know what the ideal tyre pressure would be?
I'm looking for economy as much as handling......actually maybe more so.
On the modern I just look inside the door but obviously the triumph has aftermarket wheels and tyres so it pressure wouldnt be standard?

Whats everyone else run at?

[thescrapman]

15 inch wheels with 205/65-15 tyres and I run about 26.

Seems OK.

The tyres were worn slightly oddly so haven't paid too much attention to wear.

Steering is fine on the move, still heavy when parking.

There was athread discussingthis a year or so back I think.

Cheers

Colin

[Alex]

I just wondered wether with modern tyres I should run much higher pressure than Triumph recommended?
Modern cars seem to run much higher pressure's our 406 runs at about 30 maybe more and thats got practically the same size tyres fitted.

Oh and I may have asked this question before myself ;D

[thebrookster]

Aye, but do remember that our Triumphs are a fair bit lighter than most modern cars. Pressures are all to do with keeping the correct amount of tread on the road, too soft and you run on the sidewalls, to hard and you run on the centre of the tread.

At the same time, higher pressure means better fuel economy becuase less friction, whilst lower pressures mean more grip.

What you end up running depends on what type of driving you do, I personally run slightly softer for hard runs (only a bit in my case otherwise I suffer tyre roll) and harder for motorway to get better mpg. I drive accordingly when on harder as I know I have less grip.

You can start theorising about changing pressures from standard because of wider tyres, but IMHO it will not make that much of a difference.

[Alex]

The peugeot weighs about 1400kg the 2000 about 1200kg.
The triumph pressure would have been 26psi the peugeot is 36psi....quite a difference for a similar weight?
I tend to run about 28 on the 2000.....if I check them(so not very often) but maybe I'll try them a bit harder as they always look a bit soft.....
Then I'll just have to keep a check on the wear characteristics.....

[TedTaylor]

Keep an eye on how the tread is wearing - obviously it should wear pretty evenly over the whole tread surface.

If wearing more in the middle pressures are too high.  If wearing too much on the outside the pressures are too low.

Ted

[drofgum]

Hi all,
One point that may need to be thought about is that modern radial tyres don't suffer as much from the over pressure center wear as bias ply tyres for which our cars were originally designed. The steel belt does a very good job of keeping the tread from bulging in the center. This is part of the reason that modern cars can use pressures so much higher than once were common; even on tyres that are quite a bit wider. Modern suspension design, especially the bushings, allows this without the ride becoming intolerably harsh.
                                                           Cheers,
                                                           Paul

[piman]

Hello Philip,

"whilst lower pressures mean more grip."

On the contrary, that will give less grip on normal roads, i.e apart from exceptions like snow.

Personally I run 32 to 34 psi on my MK 1, on standard P.I. sized tyres, (i couldn't get the 175s I wanted)

Alec

[Lord Sorbington]

1317 wrote:

Hi all,
One point that may need to be thought about is that modern radial tyres don't suffer as much from the over pressure center wear as bias ply tyres for which our cars were originally designed. The steel belt does a very good job of keeping the tread from bulging in the center. This is part of the reason that modern cars can use pressures so much higher than once were common; even on tyres that are quite a bit wider. Modern suspension design, especially the bushings, allows this without the ride becoming intolerably harsh.
                                                           Cheers,
                                                           Paul

Plus suspension on modern cars has far less camber variation over the range of movement so doesn't rely so much on tyre flex to keep the tread in contact with the road.

[ferny]

piman wrote:

Hello Philip,

"whilst lower pressures mean more grip."

On the contrary, that will give less grip on normal roads, i.e apart from exceptions like snow.

Personally I run 32 to 34 psi on my MK 1, on standard P.I. sized tyres, (i couldn't get the 175s I wanted)

Alec

I always ran 24 (front) 26 (back) on the Herald. Gave for more grip than anything higher.

[piman]

Hello My Lord,

"Plus suspension on modern cars has far less camber variation "

I'm glad you mentioned that, so why does everyone it seems, want to put wider lower profile tyre on their 2000s?

Ferny, that may suit your Herald, and I assume you are talking radial tyres?
Incidentaly when radials first came out they were referred to as 'low pressure tyres' because of the greater tyrewall bulge.

Alec

[Tim Bancroft]

Alex,

I run my saloon at 29-30PSI, seems fine. In fact I run the GT6 at these as well.

[CRAJ]

The estate has 195/70/14 on 6x14 MOMOs, these are run at about 28psi front 33psi rear (estates always had higher pressures at the rear).
Any higher than that at the front and the already light PAS becomes 'american' if you know what I mean. ;)

Colin.