[bravo6]

Originally Posted by saket77

7. After this trip, tire pressure figures got inverted - from 25 psi to 52 psi. I am not a math expert, neither a Physics student. Cannot comment if air pressure can double. But if it can, then one can start with as low as 15-20 psi and still get over-inflated tyres by the time he is done with his drive.

Tyre pressure reading does increase with rise in temperature. What manufacturers recommend are cold tyre pressure, meaning you need to set them before you start driving. If your nearest air compressor is 2km away, you would have to compensate for it by adding a couple of PSI to the recommeded value.

If you start out with say 5PSI less than recommended, drive for 20km, then check the air pressure, it may very well read 5PSI above recommended!

Best practise would be to overinflate the tyre slightly on your way back home (if you don't have an air pump). Park the car overnight and set the pressure using your own accurate pressure guage before heading out.

Originally Posted by gowda79

It will stay same when you are driving in the night due to the cool outside temperature which makes the tyre cool.

I would have to disagree with you. Day or night, the tyres will always be warmer after a long drive, though the difference would be lower during the night. Touch the tyre and feel it yourself.

We usually get our car tyres inflated to 30 whereas the manufacturer says 35 before going on a long road trip.

I thought we had established low pressure increases heat production and tyre wear? A lower pressure makes the ride softer, which is good for bumpy city roads, but bad for long distances, where the excess heat would cause a blow-out. Please stick to what the maufacturer recommends. They would after all have tested thoroughly to arrive at that number.

Also, a fully loaded vehicle would need a higher pressure than one with just the driver.

Originally Posted by msdivy

What is the normal or expected increase in pressure on driving continuously for 2 hours?

Originally Posted by honeybee

We had the TPMS installed on our Ikon a couple years back. While it was new I once measured it on the expressway from our home to Pune. The increase in the air pressure was of about 10 to 12 PSI while the temperature showed a similar increase too.

I too have never noticed an increase beyond 10PSI after long drives. (Disadvantage of starting early in the morning, if you forget to check the pressure the previous night.)

TL, DR:
Lower pressure + Short, city drives --> OK (for comfort), increased tyre wear
Lower pressure + Long, highway drives --> may cause blow out, increased tyre wear
Lower pressure + Long, highway drives in rains --> OK (gives more traction), water keeps the tyres cool
Recommended pressure + Long, highway drives --> Best compromise between ride comfort, safety and tyre wear
Higher pressure --> OK for smooth, dry roads. Reduced comfort, increased economy, decreased traction. Required for higher speeds

[rulerofsun]

Originally Posted by msdivy

What is the normal or expected increase in pressure on driving continuously for 2 hours?

There are a number of factors that will effect this; Read:

http://www.team-bhp.com/forum/techni...y-driving.html

or

http://www.tirerack.com/tires/tirete....jsp?techid=73

[bravo6]

A page from an old Camry's manual, showing recommended tyre pressures depending on load and speed.

@mods please merge with my previous post if required

[gowda79]

Originally Posted by bravo6

I would have to disagree with you. Day or night, the tyres will always be warmer after a long drive, though the difference would be lower during the night. Touch the tyre and feel it yourself.

Bravo, this is what i was saying and you have put it in a different way.

[bravo6]

Haha ok.

By the way, for those that claim running on Nitrogen leads to cooler running tyres, wouldn't it give you less traction since the tyres never (or take a very long time to) truly "warm up"?

[SS-Traveller]

http://timesofindia.indiatimes.com/c...w/38577687.cms

AHMEDABAD: Think twice before you unleash the speed demon on the Ahmedabad-Vadodara Expressway (NE-1). Burning rubber on this stretch could cost your life if you choose to ignore the correct tyre pressure.

In a year, this 95 km long expressway saw an alarming 92% rise in the number of accidents — the highest in recent years — from 401 in 2012-13 to 771 in 2013-14. Even though the number of deaths has gone down, the rise in accidents is a cause of concern for traffic authorities.

In nearly 15% accident cases, tyre blow-outs, overturning and skidding due to tyre pressure more than permissible limits were found to be the main reasons, revealed a recent study carried out by Ahmedabad traffic police.

Project director of the expressway H C Modi said, "At high speeds, friction between tyres and the road results in air pressure increasing. If tyres have a pressure of 32-35 PSI, it goes up to 40-45 PSI. This leads to excessive heat generation resulting in accidents. Nearly 15% accidents are because of wrong tyre pressure."

The city traffic department will now approach the National Highways Authority of India (NHAI) with the findings. It plans to recommend setting up booths that will compulsorily measure tyre pressure of all vehicles before letting them go — a pressure of 26 PSI, or pounds per square inch, will only be allowed.

Last month, four people travelling in an Ahmedabad-bound Surat vehicle — an SUV — died on the spot after the front tyre burst. The SUV turned turtle and was hit by an oncoming vehicle. The incident also left two grievously injured. Last year, 39 people died in accidents on the expressway.

Experts also point that most drivers indulge in high-speed driving, excessive cornering and frequent braking without knowing the 'tyre codes' that indicate load capacity and maximum speed, which result in accidents.

Deputy commissioner of police, traffic, Rajdeepsinh Jhala said, "Our study revealed that most commuters drive their vehicles with air pressure of 32 PSI both in the city as well as on the expressway, which can prove fatal."

The article is seriously misleading in its content. I for one will have to refuse to have my tyre pressures tampered with and reset to 26 psi. And I would certainly like to take a close look at the study purportedly conducted by DCP (Traffic) Ahmedabad which infers that driving with 32 psi on an expressway "can prove fatal".

[saket77]

Originally Posted by SS-Traveller

http://timesofindia.indiatimes.com/c...w/38577687.cms


The article is seriously misleading in its content. I for one will have to refuse to have my tyre pressures tampered with and reset to 26 psi. And I would certainly like to take a close look at the study purportedly conducted by DCP (Traffic) Ahmedabad which infers that driving with 32 psi on an expressway "can prove fatal".

Half knowledge is so dangerous. In fact, they may 'kill' a lot more people with their half baked knowledge of '26PSI'. By the time of their 'compulsory air pressure check', most tires would be running hot. And 26 PSI on a tire which has already run some good distance means an under-inflated tyre.
And if people, as owners of the car, cannot keep something as simple as cold tire pressure in check, then they do not deserve to drive a car in first place.

[Danindica]

Cemented or not, the roads weren't the problem. Our tyres were close to seventy thousand kms and four years old. They had gotten rough too. So, it was a delight to experience the velvety ride on those new Bridgestones bought in Goa; 140kmph and all. By the way, it is true that the tyres heat up quicker on cemented patches. Have seen that happening.

[Requiem]

https://www.youtube.com/watch?v=AlhgZaR30A0

This post contains the street racing elements which are prohibited on the forum, but I think people need to see how a high speed tyre blowout needs to be handled.
By not braking, and slow releasing the gas pedal, this guy contained the situation perfectly.

[AZ911]

Originally Posted by Requiem

This post contains the street racing elements which are prohibited on the forum, but I think people need to see how a high speed tyre blowout needs to be handled.
By not braking, and slow releasing the gas pedal, this guy contained the situation perfectly.

It's hard not to panic when you have a tyre burst even if at half the speed of what is shown in the video.

I think it's better and safer to opt for a Tpms which displays the tyre temperature and has warning based alerts, especially for highway diving in summers. For 8-9K, it can prove to be a lifesaver.

[nitinbose]

Interestingly, I found the same article here: http://www.wikihow.com/Handle-a-Tyre-Burst with the identical wording.

[Jack Sparrow]

Hope you did not miss the below one on the same page....

[swageo]

Any risk of tyre burst if I take on highway with all new tyres for long driver 10+h ?. Any preconditioning like (under 80kmph for first 100 km) I should follow ?

[Santoshbhat]

Originally Posted by swageo

Any risk of tyre burst if I take on highway with all new tyres for long driver 10+h ?. Any preconditioning like (under 80kmph for first 100 km) I should follow ?

No risk of tyre burst with new tyres.

Make sure you don't push too hard with new tyres as new tyres take a few 100 kms to start gripping very well.

[Jeroen]

Originally Posted by SS-Traveller

http://timesofindia.indiatimes.com/c...w/38577687.cms


The article is seriously misleading in its content. I for one will have to refuse to have my tyre pressures tampered with and reset to 26 psi. And I would certainly like to take a close look at the study purportedly conducted by DCP (Traffic) Ahmedabad which infers that driving with 32 psi on an expressway "can prove fatal".

I agree. They seem to completely disregards the advise of every car and tyre manufacturer that for high speed driving you would typically inflate your tyres by 5-8 psi over the normal cold air tyre pressure.

If anything low pressure leads to excessive heat generation, subsequent higher air pressure. I would think that the main cause of blow outs is worn tyres to start with, to low pressure and your typical Indian road surface.

Jeroen