[braindead]

Here is the problem of tyre pressures from my observation:
If the pressure is correct eg 30psi [cold], the pressure will go up to about 35psi when hot.
If the pressure is low eg 25psi [cold], the pressure will go up more due to excess heat buildup to 35psi again when hot.

But in the second case, the pressure is going to be much more unstable.
Now, when you fill up air at the food mall at the expressway, you are actually deflating 5 or so psi. The result is going to be more instability of tyre pressures - even if the tyres 'look' ok.
Also, if you add outside air to an already hot tyre, the new air is going to expand and raise tyre pressure beyond what you filled up.

Moral of the story: Checking tyre pressures cold is very important. I use and recommend a small electric air pump that runs off the onboard 12v socket. It honestly doesn't matter if the psi reading is not very accurate - as long as its somewhat consistent.

[pixantz]

Alright, this subject about tyre pressure always amazes me as to how people use their imagination about keeping certain pressures higher or lower than the recommended point. It just blows me away.

I mean, no offense, but the manufacturer has already tested everything under ALL POSSIBLE CIRCUMSTANCES and then kept the said recommendation of pressure. There is a reason why it is a certain level. Now why do people imagine that they know better than the people who made the car in the first place, is just beyond my imagination. At least in such critical things. Does anyone think that the manufacturer was not aware that tyre pressures increase on hot asphalt and hence wrongly said 30psi? I don't think so.

[paragsachania]

Originally Posted by pixantz

I mean, no offense, but the manufacturer has already tested everything under ALL POSSIBLE CIRCUMSTANCES and then kept the said recommendation of pressure. There is a reason why it is a certain level.

You nailed it!

Manufacturer recommends a tire pressure are hence recommended for driving, Period!

Additionally, most of the tires manufactured for India are made for withstanding the heat due to friction for Indian conditions.

Till date (touchwood first) I have never set the tire pressure (less or more) based on whether I am driving on highway or city due to which there was any incident/accident. The pressures were mainly based on the load factor.

The biggest "lie" we ever get to hear/read - "Accident due to tire burst" where in reality, most of these accidents would be after the driver brushed the median first and then caused the tire burst. Of course, the type of median on MPEW cannot really cause tire burst but would certainly damage your tire and rim as these are brick like blocks in most sections than continuous.

The mistakes: Running on totally bald tires, susceptible to punctures even due to small stones, Running on wrong tire pressures completely far from what was recommended, Running on a weaker tube (Yes, we still see many using tube type tires)

[bullrun87]

Originally Posted by pixantz

Alright, this subject about tyre pressure always amazes me as to how people use their imagination about keeping certain pressures higher or lower than the recommended point. It just blows me away.

I mean, no offense, but the manufacturer has already tested everything under ALL POSSIBLE CIRCUMSTANCES and then kept the said recommendation of pressure. There is a reason why it is a certain level. Now why do people imagine that they know better than the people who made the car in the first place, is just beyond my imagination. At least in such critical things. Does anyone think that the manufacturer was not aware that tyre pressures increase on hot asphalt and hence wrongly said 30psi? I don't think so.

You're right. Ford suggests 30-35 psi depending on the number of passengers and I like to keep it in the middle of the range. One should keep in mind that these tyre pressures are at ambient temperature conditions and the tyre pressure will increase or decrease in response to ambient conditions but the manufacturer has already compensated for that! Let's say maruti recommends 30psi for a car and you adjust the pressure in the morning to the recommended level. If you go on a highway run and tyre temperatures increase by about 30 degrees, a typical value for a highway run then your pressure would increase by about 3 psi using some basic physics Similarly in the night if temperatures reduce by about 10-15 degrees your pressure reduces by 1-2 psi. Either way you are operating in the 28-33 psi range which is fine.

[Thad E Ginathom]

Tyres should be filled and pressure tested when cool. Difference in temperature due to warming them up is then included in their design and the recommended pressure.

Do not reduce your tyre pressures for any such reason as highway driving!

[GJ01]

Originally Posted by sukhoi30

The cause of the accident seemed to be burst tyre.

It doesnt look like any of the tyres had suffered a tyre burst looking at the pictures. All 4 tyres look OK to me - If any one would have burst - and given that the car then hit the median and flipped - I would have expected it to be loose on the wheel rim. That doesnt seem to be the case.
Could be a lapse in driving that led the driver to hit the median, which would have caused the driver to do a massive overcorrection leading to the flip.

[kiku007]

Originally Posted by kiran_cr

Not sure if they checked the tyre pressure before venturing out on a high speed drive.
I normally reduce the tyre pressure by 1psi in winter and by 2psi in summer, than recommended pressure ratings, before venturing out on highways.

Just curious, do you also alter tyre pressure for high speed drive during Day vs night, Rain Vs No-rain etc.?

[suresh_gs]

Originally Posted by kiku007

Just curious, do you also alter tyre pressure for high speed drive during Day vs night, Rain Vs No-rain etc.?

Generally for driving during rain, it is advisable to reduce the tyre pressure by about 1-2 psi so that the contact area is more.

[ecenandu]

Originally Posted by paragsachania

You nailed it!
The biggest "lie" we ever get to hear/read - "Accident due to tire burst"

I have experienced tyre burst, twice. Well, sort of.

The first time was, when we had Opel Astra, most likely 14 years ago. It came factory fitted with GoodYear tyres. Which I believe had manufacturing defect, we had plenty of punctures in first few months. One time, it happened on highway we were doing good speed, suddenly we heard a loud pop, the driver we had then was a good chap, he handled the situation pretty well, pulled over to the side of the road without any drama. IIRC, it was front left tyre that was flat, no air at all. It was a tube burst and not a tyre burst.

Second incident also can't be classified as a tyre burst, after the Indica hit my car, I lost the front tyre pressure completely. I don't remember exactly now but I definitely felt something fishy with the steering before pulling over to the side of the road.

But I have seen videos of genuine tyre burst, it looks a lot scary. It is almost impossible to control the vehicle during front tyre bursts at high speeds, I think.

Anyone else had similar experiences?

[paragsachania]

Originally Posted by ecenandu

Which I believe had manufacturing defect, we had plenty of punctures in first few months.

Second incident also can't be classified as a tyre burst, after the Indica hit my car, I lost the front tyre pressure completely.

Both of these incidents are due to tire burst either due a defective tire an incident. However, the point I was trying to make is that most of the accidents where a car jumps the median and heads on the other side of the corridor is always classified as "tire burst" when in reality the tire would have burst after brushing with the median and not before!

So, not all the accidents are due to reasons like you mention but sadly most of them reported simply shut the case by blaming tire burst. There can be no real way to ascertain whether the tire burst before or during an accident.

[aayushnair]

Hi All,

I had gone out for a drive in the morning today at 0500 hours to Lonavla; and while returning at around 0810 hours at the turn just before Lions Point (in the forest area) was a Honda City (new type) crashed on the Left Side (wrong side for the direction it was facing in). This wouldve happened just minutes before as the people in the car (4 girls and 1 boy) were out on the road.

Some other people had also stopped (including me) to help, and I saw one of the injured (her face was hurt) being taken in to a locals Maruti Zen and driven to the hospital.

2 other girls were left behind alone (without anyone else from the group) so my wife and I decided to stay back and help. They were in total shock (obviously), offered them a ride but they just fought with each other (from the interactions we heard; they were siblings)

The car's axle was a gonner; both airbags were deployed and there wouldve been side and under body damage as well (sorry didnt take a pic as I was helping out - didnt seem appropriate).
From the interactions with the 2 girls; the driver (their friend; the car owner (another girl) was drunk and crashed at speed first into the LHS barrier with the momentum taking the car to its right into the ditch on my side of the road (towards Mumbai). If they had gone over on the LHS the situation wouldve been much different (down the slope and into the jungle - atleast 30 - 40 feet)

They had a miraculous escape.

Anyway; waited for them to complete their fight and blame games for close to 30 minutes; in vain. Both my wife and I tried convincing them to let the car be and call a towing company and get some sort of medical check up or atleast wait with their friends at the hospital; it was just going to be an easy pick for any goon (considering they had already lost their bags and their mobiles had run out of money). They just continued their now very irritating argument; and also by then 2 cars had stopped to offer support and turned away looking at their drama.

We decided to leave, considering there wasnt much they were listening to.

In this whole commotion, since we had offered help and our phones to make calls; one of their phones ended up with us (we realized this only once we were in Navi Mumbai). We went through the contact list, but couldnt find an ICE no. We received a call from them a few minutes later, have planned a meet in the eve to hand their phone over back to them.

Man, this whole holiday turned around for us; but I'm glad I stopped and tried to help and also that others did too.

Cheers,
Aayush.

[Chewbacca]

Originally Posted by suresh_gs

Generally for driving during rain, it is advisable to reduce the tyre pressure by about 1-2 psi so that the contact area is more.

IMO it is a lose-lose situation so just keep the recommonded pressure, no less no more.

Lower pressures will give better grip and breakaway/recovery but higher pressures will be better in resisting aquaplaning.

More contact area = higher the risk of aquaplaning
Choose your poison

[kiku007]

Originally Posted by kiran_cr

I normally reduce the tyre pressure by 1psi in winter and by 2psi in summer, than recommended pressure ratings, before venturing out on highways.

Incorrect. Suicidal.

Originally Posted by kiku007

Just curious, do you also alter tyre pressure for high speed drive during Day vs night, Rain Vs No-rain etc.?

Sarcasm.

Originally Posted by suresh_gs

Generally for driving during rain, it is advisable to reduce the tyre pressure by about 1-2 psi so that the contact area is more.

Incorrect. Suicidal.

Originally Posted by pixantz

Alright, this subject about tyre pressure always amazes me as to how people use their imagination about keeping certain pressures higher or lower than the recommended point. It just blows me away.

I mean, no offense, but the manufacturer has already tested everything under ALL POSSIBLE CIRCUMSTANCES and then kept the said recommendation of pressure. There is a reason why it is a certain level. Now why do people imagine that they know better than the people who made the car in the first place, is just beyond my imagination. At least in such critical things. Does anyone think that the manufacturer was not aware that tyre pressures increase on hot asphalt and hence wrongly said 30psi? I don't think so.

Correct operating procedure. Period.

[motomaverick]

Just saw this news in Facebook BTP page. Zoomcar topled near Airview from Indiranagar. No news on how this happened, driver side looks bad.

[sanjaykk]

Originally Posted by motomaverick

Just saw this news in Facebook BTP page. Zoomcar topled near Airview from Indiranagar. No news on how this happened, driver side looks bad.

Attachment 1584604

Saw this being towed away around 8:45am.