[sbasak]

Using slighly higher pressure (+ 2-3 psi) than manufacturer's recommendation usually results in stiffer ride yet better fuel ecomony.

eg.

What's your opinion on it?

[falcon]

A slightly higher pressure would improve your fuel economy, but it does have other side effects too.
Possibly uneven tyre wear.
Stiffer tyres means harder ride, and also more wear n tear of the suspension.

These are my observations with my M800 when I drove it with higher pressure for a couple of thousand kms.

[passionpurple]

even I have noticed the same tyre wear situation.. overinflation results in excess wear of the centrally located tyre threads

but also a better efficiency

[Shan2nu]

Tyre pressure need not necessarily be as per the company recomended fig. You can increase it by 2-3 psi and see if it affects tyre wear. The suspension will only suffer if the pressure is increase by a very large margin.

On a regular day, my car has 30psi(F) 29psi(R).
For my high speed drives, it's 33 (F) 31(R).
If I have to carry 5 people on a long journey, it's 33(F) 32(R).
Recomended pressure 29(F) 29(R).

Shan2nu

[imjimmy]

For my high speed drives, it's 33 (F) 31(R).

That's 4 psi more at the front and 2 psi more at the rear w.r.t recommended tyre pressure.!!
How can you do with so much of pressure, it would ruin the handling and the car might develop rattles at very rough roads at high speeds.

I understand the pt of 1 Psi increase on highways.But this seems to be too much.

[Shan2nu]

That's 4 psi more at the front and 2 psi more at the rear w.r.t recommended tyre pressure.!!
How can you do with so much of pressure, it would ruin the handling and the car might develop rattles at very rough roads at high speeds.

Firstly, i don't rip on bad roads. 2ndly, it improves the handling on my car, as the flexing of the sidewalls is reduced considerably. The steering is sharper and the road holding is brilliant.

The figures given by the company are usually comfort oriented, not ideal for performance driving. You have to set yourself a fixed figure depending on your requirements.

I haven't faced any rattles, squeaks or uneven tyre wear.

Shan2nu

[cnu]

Slightly off topic, but can any one tell me why the recommended pressure for the front tyres is more than the pressure for the rear ones for some of the cars (for eg, for the NHC the recommended pressures are 32 (Front) and 30 (Rear)). Is it just for the extra comfort for the rear seats ?

[Zappo]

Originally Posted by cnu

Slightly off topic, but can any one tell me why the recommended pressure for the front tyres is more than the pressure for the rear ones for some of the cars (for eg, for the NHC the recommended pressures are 32 (Front) and 30 (Rear)). Is it just for the extra comfort for the rear seats ?

I believe that has to do with the front load vis-a-vis the back. Since the engine bay is at the front and the front wheels bear the load they require more air pressure. Diesel cars may have a difference of 2 psi or more between the rear and fore wheels as the diesel engines are heavier.

Also, it is a known fact that more often than not the rear seat of a car goes unoccupied (I am not talking of the chauffer driven ppl ). In such cases your back will be even lighter and if the inflation were to be the same as the front wheels the rear may bounce all over the place.

[RX135]

Originally Posted by cnu

Slightly off topic, but can any one tell me why the recommended pressure for the front tyres is more than the pressure for the rear ones for some of the cars (for eg, for the NHC the recommended pressures are 32 (Front) and 30 (Rear)). Is it just for the extra comfort for the rear seats ?

Nope. You have heavy engine in front as compared to less loaded rear. Unless of course, you have rear engine car.

[sbasak]

http://www.cybersteering.com/cruise/...e/driving.html
You'll find here some reasons about front/rear tyre pressure logic.

[suman]

Originally Posted by Shan2nu

The figures given by the company are usually comfort oriented, not ideal for performance driving. You have to set yourself a fixed figure depending on your requirements.

The Fiesta talks about 30 psi on cold tyres - this may be a stupid question but how cold? I mean you may have already driven 13 kms to your pump from a cold start, is that cold enough or what? Any ideas? . Would it be a accurate guesstimate to add on 2 psi if you are checking it out in summer conditions after a 13 km drive?

[speedsatya]

Originally Posted by suman

The Fiesta talks about 30 psi on cold tyres - this may be a stupid question but how cold? I mean you may have already driven 13 kms to your pump from a cold start, ?

cold tire pressure is the pressure before the tire starts rollling ...13 kms is sufficient to heat up your tires ...and you will not get the right reading ...thebest thing is to buy a foot pump and fill air once a week before u start driving ...


http://www.discounttire.com/dtcs/infoAirPressure.dos

[suman]

Originally Posted by speedsatya

cold tire pressure is the pressure before the tire starts rollling ...13 kms is sufficient to heat up your tires ...and you will not get the right reading ...thebest thing is to buy a foot pump and fill air once a week before u start driving ...

Thanks, thats what I thought as well!

About the foot pump, does it come with a meter as well or how do you figure out if you are filling 30psi or 20?

[5u3zEr0]

Or we could inflate the tyre by 2-3psi more than normal when the tyre is hot, like I do. I inflate my car at 32 psi all round when the tyre is hot when the recommended is 28psi.

[hot_rod]

see the main thing is that the manufacturer recommends the pressure taking all aspects in consideration eg:tyre wear and tear,fuel economy,ride comfort,handling etc!so it all boils down to the way you drive your car if u want more efficieny then you can increase the psi to a max of ard 4psi than the given pressure but you will compromise on road grip and tire wear as well as ride comfort!with the rising fuel prices you think for yourself which is more important!!