80psi in a tyre

RebelButtMunch

Hi.
I was sitting for ages today behind a guy who was topping up his car tyres. It seemed like he was at it for a while. IIRC it was a bmw3 or audi a3. Anyway when he finally pulled away and I got to the machine he had it up to 80psi ! Is that in any way normal for a car?

Atlantic Dawn

No wouldn't be normal for a car.

kirving

Was it a space saver spare tyre?

Posted it before, but I did hear of someone who just pumped up their tyres 'till they were round"

zl1whqvjs75cdy

I'm surprised the thing didn't explode in his face. Clown.

RebelButtMunch

Kevin Irving wrote: »

Was it a space saver spare tyre?

Posted it before, but I did hear of someone who just pumped up their tyres 'till they were round"

Lol.. From being parked behind it looked the same as the tyre on the other side so I guess it wasn't a space saver.

fancy pigeon

Maybe he wanted to go round.... :P

Surprised the valve didn't let go, which I've seen happen at 70psi on a car tyre....

AMGer

Is it even possible for a 3 series/A3 type tyre to take 80psi? I wouldn't have thought so.

Stoolbend

I've seen car tyres pumped over 100 psi.

People are stupid.

Sam Kade

A great way to wear the tyre at that pressure also it's a recipe for aquaplaning in this weather as there is less road contact with an over inflated tyre.

CJhaughey

Wait till they hit a pothole, the results will be..... surprising to say the least.

kay 9

I've seen it numerous times. Alot of folk keep pumping until it (looks pumped) lol. Half the forecourt guages in the country are out of calibration but not that much. Hence why I carry a pen pressure gauge m

pablo128

That reminds me. I keep meaning to show the missus how to check her tyres. If it's dry tomorrow, I might bring her down and show her and be done with it.

Armchair Andy

Sam Kade wrote:

A great way to wear the tyre at that pressure also it's a recipe for aquaplaning in this weather as there is less road contact with an over inflated tyre.

I've 38 psi on my 225 45 18 and never thought it could contribute to aquaplaning. Did a long trip on Stephens and more than once coming off roundabout got a few slips. Down to tyre pressure? Less than 5k on Michelin supersports pilot 2.

galvo_clare

Remember driving the brother's rwd Starlet years ago and knew something was wrong.
Talking to him that evening it suddenly hit me.
'What pressure do you have in the tyres?'

'80. Same as the bike.'

RebelButtMunch wrote: »

Hi.
I was sitting for ages today behind a guy who was topping up his car tyres. It seemed like he was at it for a while. IIRC it was a bmw3 or audi a3. Anyway when he finally pulled away and I got to the machine he had it up to 80psi ! Is that in any way normal for a car?

ianobrien

Armchair Andy wrote: »

I've 38 psi on my 225 45 18 and never thought it could contribute to aquaplaning. Did a long trip on Stephens and more than once coming off roundabout got a few slips. Down to tyre pressure? Less than 5k on Michelin supersports pilot 2.

Possibly. Whats the pressure supposed to be for the car empty and full?

Armchair Andy

ianobrien wrote:

Possibly. Whats the pressure supposed to be for the car empty and full?

I know it's on the door sill but can't remember. Think it's 34/38 but I always thought that was rear/front( higher on the front). Dunno why... Car was heavier than usual now that you say it.

SBPhoto

I drive an A3 Saloon with 18' wheels and i use 37psi front and back.

sdanseo

Kevin Irving wrote: »

Was it a space saver spare tyre?

Posted it before, but I did hear of someone who just pumped up their tyres 'till they were round"

kay 9 wrote: »

I've seen it numerous times. Alot of folk keep pumping until it (looks pumped) lol. Half the forecourt guages in the country are out of calibration but not that much. Hence why I carry a pen pressure gauge m

I remember a gauge in Athlone that didn't work at all once, coming home from Galway. Old manual type. I'm sure it's not uncommon.

To be fair, the lady in the shop did warn me to be careful. Got the impression it had probably been like that for weeks or months.

Hal1

There'll be some bang out of that when they let go, and yer man will not half **** himself .

ianobrien

Armchair Andy wrote: »

I know it's on the door sill but can't remember. Think it's 34/38 but I always thought that was rear/front( higher on the front). Dunno why... Car was heavier than usual now that you say it.

The plate will have 4 or 5 pressures on it. Front and rear empty (driver/passenger and empty boot). It will have the same full (4 passengers and a full boot). The spare pressure could be written there also.

The VAG MQB runs rather high tyre pressures. Mine says 40psi front and back for a loaded car.

Del2005

RebelButtMunch wrote: »

Hi.
I was sitting for ages today behind a guy who was topping up his car tyres. It seemed like he was at it for a while. IIRC it was a bmw3 or audi a3. Anyway when he finally pulled away and I got to the machine he had it up to 80psi ! Is that in any way normal for a car?

Someone posted a while ago that they look at the maximum pressure allowed on the tyre and pump it to that. Didn't realise that others where doing it, at least that poster now knows the correct pressure.

What makes it even worse is the rise of ditch finders being the 1st choice for the majority of motorists. Over inflated tyres that don't grip at the best of times, no wonder insurance is going up. But sure it's only speed that kills so once they don't exceed 80km/h they are fine.

I know that there is a part of the driving test that includes questions on daily checks and how to do them, does it include knowing the tyre pressure or just how to check it?

Senecio

Talk of poorly calibrated pumps in garages reminds why this was the best €30 I've spent on my cars.

http://www.amazon.co.uk/Michelin-Hi-Power-Inflator-Detachable-Digital/dp/B000V5IG5U

Del2005

sdanseo wrote: »

I remember a gauge in Athlone that didn't work at all once, coming home from Galway. Old manual type. I'm sure it's not uncommon.

To be fair, the lady in the shop did warn me to be careful. Got the impression it had probably been like that for weeks or months.

If people had more respect for expensive equipment then petrol stations air gauges would work correctly, but people want compressed air for free and then throw the gauge onto the ground to drive over it as they leave the forecourt.

Bigcheeze

Could this cause serious injury or deafness if it blew while pumping? I've heard of truck tyres killing people.

The garage pumps should really be limited to below 40psi . People are idiots and some probably get mixed up with bar and psi.

challengemaster

Bigcheeze wrote: »

Could this cause serious injury or deafness if it blew while pumping? I've heard of truck tyres killing people.

The garage pumps should really be limited to below 40psi . People are idiots and some probably get mixed up with bar and psi.

Deafness would be the least of your worries if it blew in your face.

galvo_clare

I use the lines to blow up my bike tyres to 80psi and I'm sure I'm not alone.

I once pumped tyres on a hand trolley, forgetting that the tyre had a tiny volume.
The plastic wheel shattered with an almighty bang. I was a bit worried about opening my eyes again in case I was blind but all was well.
Then I looked down at the blood dripping from my hand.
I threw the trolley and the tyre - which had flew across the forecourt - into the van and drove myself to A & E where they stitched me up.
Very little pain until later - think I was in shock.

Bigcheeze wrote: »

Could this cause serious injury or deafness if it blew while pumping? I've heard of truck tyres killing people.

The garage pumps should really be limited to below 40psi . People are idiots and some probably get mixed up with bar and psi.

CJhaughey

challengemaster wrote: »

Deafness would be the least of your worries if it blew in your face.

You would likely have no face if it blew up in your face.

Dr_Colossus

corks finest

CJhaughey wrote: »

You would likely have no face if it blew up in your face.

Yep,never again need to buy a Halloween mask

TallGlass

fancy pigeon wrote: »

Surprised the valve didn't let go, which I've seen happen at 70psi on a car tyre....

That valve would be off like a bullet and my guess some poor innocent person would take the hit from it.

Sure even when I am putting air into my tyres on the car I always try to stand/kneel with my back to the tyre and never have my face down there, just on the off chance it blows or shoots something out.

You got to be very careful down there, some serious pressures not to be messed with.

9935452

Del2005 wrote: »

If people had more respect for expensive equipment then petrol stations air gauges would work correctly, but people want compressed air for free and then throw the gauge onto the ground to drive over it as they leave the forecourt.

True , a lot of people have little respect for things like this.
In a lot of places in england you end up paying for air at the machine.

Bigcheeze wrote: »

Could this cause serious injury or deafness if it blew while pumping? I've heard of truck tyres killing people.

The garage pumps should really be limited to below 40psi . People are idiots and some probably get mixed up with bar and psi.

The most dangerous wheels were the old style truck wheels, where when you were taking off the tyre , you had to remove a steel band/ring. If the steel band wasnt put back in correctly , when you pumped the tyre it could end up flying . I was always advised to pump these from the opposite side of the wheel with the band facing down.

It would be easy to limit the pressure to 40psi as most compressors have regulators but wouldnt really be practical. There are a good few reasons to pump above 40 psi. Space savers go to 60. i have a ifor williams which needs 90psi. Small trucks 60 , supersingles 100 psi , to name a few

Into The Blue

kay 9 wrote: »

i carry a pen pressure gauge

Where do you get it calibrated?

corks finest

TallGlass wrote: »

That valve would be off like a bullet and my guess some poor innocent person would take the hit from it.

Sure even when I am putting air into my tyres on the car I always try to stand/kneel with my back to the tyre and never have my face down there, just on the off chance it blows or shoots something out.

You got to be very careful down there, some serious pressures not to be messed with.

youre def a double johnny man,to be sure,to be sure.:P

tayto lover

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

Joe 90

Sam Kade wrote: »

A great way to wear the tyre at that pressure also it's a recipe for aquaplaning in this weather as there is less road contact with an over inflated tyre.

According to a textbook on aircraft design the formula for the apped at which aquaplaning occurs in knots is 9 * the square root of the tyre pressure in psi. That is for a tyre with no tread of any form, bald to you and me but don't forget that aircrafat do not have to corner like cars.

Make sense if you think about it, the tyre pressure is the pressure on the ground and one woukd expect the aquaplaning speed to increase with ground pressure.

I've only encountered what I would definitely call aquaplaning once and it is scary. Really scary, hoping that you will slow down before making contact with the scenery.

TallGlass

corks finest wrote: »

youre def a double johnny man,to be sure,to be sure.:P

I rather a bit of a blow of the wind up the arse than a blow to the face if you know what I mean.

Tigger

Joe 90 wrote: »

According to a textbook on aircraft design the formula for the apped at which aquaplaning occurs in knots is 9 * the square root of the tyre pressure in psi. That is for a tyre with no tread of any form, bald to you and me but don't forget that aircrafat do not have to corner like cars.

Make sense if you think about it, the tyre pressure is the pressure on the ground and one woukd expect the aquaplaning speed to increase with ground pressure.

I've only encountered what I would definitely call aquaplaning once and it is scary. Really scary, hoping that you will slow down before making contact with the scenery.

The tyre pressure isn't the pressure on the ground it's the pressure in the wheel
When the tyre shop pump you're tyres they are off the car
What is the change when you check them again on the car ? Does it change ?

deandean

That driver probably has a slow puncture that he couldn't bother fixing.
So he pumps the tyre up to 80psi and he gets 2 or 3 days out of it.
Deadly stuff.

TallGlass

deandean wrote: »

That driver probably has a slow puncture that he couldn't bother fixing.
So he pumps the tyre up to 80psi and he gets 2 or 3 days out of it.
Deadly stuff.

Yeah day or two out of the car if he keeps it up :pac:

Skatedude

I always set the pressure on the pump to be much higher then i need ie 60psi, that way the compressor charges up more and you can inflate your tires quicker, you simply stop pumping when the tyres are at the correct pressure, ie 32psi.

If you set the pump to 32psi etc, it just takes much longer as the compresser pump dosent run as much. but this only applies to the newer pumps where you can input the desired pressure in advance.

Or his tyres are actually at 80 and will go off like a bomb if he hits a pot hole.