Tyre pressure - how low can you go?

faffi · Sep 16th, 2011, 19:01

I'm running 196/65-15 and find the ride unpleasantly harsh, something I've also discussed in a separate topic. But I should be able to let the tyres do some of the job that the suspension fail to perform with lower pressure. Have somebody found the lower limit before tyres start to wear abnormally? Would 30 PSI be sufficient for normal low speed driving? Can one go even lower? I'm not concerned about handling.

Ninja59 · Sep 16th, 2011, 19:17

first problem with running lower pressure is you increase the resistance and therefore increase fuel consumption

usually it is best to keep around the correct pressures from volvo in my case around 32 PSI iirc on the c30 for 2 up and 36 for 4 up but it is to bouncy when only 2 up at the higher pressure.

Daim · Sep 16th, 2011, 19:53

It doesn't go by what Volvo says. The people who know what a tire can cope with, would be...? Guess! The tire manufacturer.

Contact your tire manufacturer (proper companies have a service for this) and ask what the proper pressure would be for your tire on your rims!

Why? Because every tire has a different "mould". This difference can equal a different pressure. The same counts for the rim. The rim can be for example 6.5" wide and with a 195/65 R15 tire (example still!) a pressure of say 2.5 bar would be okay. A 6.0" wide rim with the same tire could use say 2.6 bar.

I have currently 225/35 R19 on 8.5" wide rims. They are stretched a little bit. I asked my dealership. They said "2.8 bar is ideal". I wrote to Kumho and got the answer "2.2 bar at the front, 2.1 bar at the rear is ideal". I am currently 0.1 bar at the front and back below that recommendation to ease off the saw tooth caused by the Volvo specs.

My winter tires - Barums - are the mentioned 195/65 R15 on 6.5" wide rims. Volvo says "no more than 2.5 bar!" - Barum says "3.0 bar is no worry, higher would be a little too much, 2.3 bar a little too little". So before anyone here gives you a clear recommendation, contact the tire manufacturer and ask your desired specs

faffi · Sep 16th, 2011, 20:55

Good advice, Daim

faffi · Sep 16th, 2011, 21:11

Checked it out, and Michelin recommend 2.1 bar for both my summer and winter tyres. This equals 30 PSI.

Daim · Sep 16th, 2011, 22:23

See

Most people don't want to believe that, but it really is what you should do, before you even fit the tires...

Clan · Sep 16th, 2011, 23:00

Quote:

Originally Posted by faffi

Checked it out, and Michelin recommend 2.1 bar for both my summer and winter tyres. This equals 30 PSI.

the only problem there is the edges will wear prematurely, eco pressures are 38 psi ... ..

Metblackrat · Sep 17th, 2011, 09:29

A tyre that is more than 10% underinflated is an offence that leaves you with a 3 point blot on your licence.

Daim · Sep 17th, 2011, 12:11

Quote:

Originally Posted by Metblackrat

A tyre that is more than 10% underinflated is an offence that leaves you with a 3 point blot on your licence.

And who determines an underinflated tire? If the tire maker recommends that then it is recommended...

mike norman · Sep 19th, 2011, 20:16

Quote:

Originally Posted by Daim

And who determines an underinflated tire? If the tire maker recommends that then it is recommended...

BE VERY VERY CAREFUL as under inflated tyres will seriously effect handling with great potential to loss of control of the car which can have fatal IE DEATH results. BE WARNED

Sep 16th, 2011, 19:01	#1
faffi Motorcyclist Last Online: May 14th, 2015 22:34 Join Date: Jul 2010 Location: Stavanger	Tyre pressure - how low can you go? I'm running 196/65-15 and find the ride unpleasantly harsh, something I've also discussed in a separate topic. But I should be able to let the tyres do some of the job that the suspension fail to perform with lower pressure. Have somebody found the lower limit before tyres start to wear abnormally? Would 30 PSI be sufficient for normal low speed driving? Can one go even lower? I'm not concerned about handling.

Sep 16th, 2011, 19:53	#3
Daim Brit in Germany Last Online: Apr 24th, 2024 06:58 Join Date: Jan 2011 Location: Bremen	It doesn't go by what Volvo says. The people who know what a tire can cope with, would be...? Guess! The tire manufacturer. Contact your tire manufacturer (proper companies have a service for this) and ask what the proper pressure would be for your tire on your rims! Why? Because every tire has a different "mould". This difference can equal a different pressure. The same counts for the rim. The rim can be for example 6.5" wide and with a 195/65 R15 tire (example still!) a pressure of say 2.5 bar would be okay. A 6.0" wide rim with the same tire could use say 2.6 bar. I have currently 225/35 R19 on 8.5" wide rims. They are stretched a little bit. I asked my dealership. They said "2.8 bar is ideal". I wrote to Kumho and got the answer "2.2 bar at the front, 2.1 bar at the rear is ideal". I am currently 0.1 bar at the front and back below that recommendation to ease off the saw tooth caused by the Volvo specs. My winter tires - Barums - are the mentioned 195/65 R15 on 6.5" wide rims. Volvo says "no more than 2.5 bar!" - Barum says "3.0 bar is no worry, higher would be a little too much, 2.3 bar a little too little". So before anyone here gives you a clear recommendation, contact the tire manufacturer and ask your desired specs __________________ The Best Nation Is Imagination 2010 V70 (Type 135) D5 (D5244T10) Automatic (TF-80SC)

Sep 16th, 2011, 22:23	#6
Daim Brit in Germany Last Online: Apr 24th, 2024 06:58 Join Date: Jan 2011 Location: Bremen	See Most people don't want to believe that, but it really is what you should do, before you even fit the tires... __________________ The Best Nation Is Imagination 2010 V70 (Type 135) D5 (D5244T10) Automatic (TF-80SC)

Sep 16th, 2011, 19:17	#2
Ninja59 Probably Akita's Toyboy.. Last Online: Dec 27th, 2023 22:24 Join Date: Jul 2010 Location: A House.	first problem with running lower pressure is you increase the resistance and therefore increase fuel consumption usually it is best to keep around the correct pressures from volvo in my case around 32 PSI iirc on the c30 for 2 up and 36 for 4 up but it is to bouncy when only 2 up at the higher pressure.

Sep 16th, 2011, 20:55	#4
faffi Motorcyclist Last Online: May 14th, 2015 22:34 Join Date: Jul 2010 Location: Stavanger	Good advice, Daim

Sep 16th, 2011, 21:11	#5
faffi Motorcyclist Last Online: May 14th, 2015 22:34 Join Date: Jul 2010 Location: Stavanger	Checked it out, and Michelin recommend 2.1 bar for both my summer and winter tyres. This equals 30 PSI.

Sep 17th, 2011, 09:29	#8
Metblackrat Senior Member Last Online: Jul 19th, 2012 22:29 Join Date: Mar 2006 Location: Hatfield	A tyre that is more than 10% underinflated is an offence that leaves you with a 3 point blot on your licence.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)