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Petrol station tyre pressure pumps

Hi,

My car tyres are on the low side it seems, and I've never been to a petrol station to use their tyre pressure pumps and wondered if anyone could give me a quick explainer on how to use them correctly (motoring newbie here..)

Also, I've checked my car tyres to see if it gives an idea of how much to inflate them by and as they are all different manufacturers, it seems tricky to ascertain. My manual gives a list of how much to add for different tyre sizes, but I'm confused.

Any pointers gratetfully appreciated.

Thank you

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Reply 1
Original post by Aky786UK
Hi,

My car tyres are on the low side it seems, and I've never been to a petrol station to use their tyre pressure pumps and wondered if anyone could give me a quick explainer on how to use them correctly (motoring newbie here..)

Also, I've checked my car tyres to see if it gives an idea of how much to inflate them by and as they are all different manufacturers, it seems tricky to ascertain. My manual gives a list of how much to add for different tyre sizes, but I'm confused.

Any pointers gratetfully appreciated.

Thank you

There should be a sticker somewhere on your car with tyre pressures. Either in fuel filler flap or somewhere on your driver door sills is the usual place.
Yeah, there should be pressures for the car being either fully laden or unloaded in both the owners manual and (usually) on a plate inside a door sill somewhere.

The pump should have clear instructions on it. I would just make sure that you park close enough that you can get the hose around the far side of the car easily. If you look on YouTube for 'petrol station air pump' there are a few guides.

I am a mechanical imbecile and even I have managed to this on more than one occasion, so there can't be that much to it :smile:
Reply 3
Do not use whatever pressure you find on the sidewall of the tyre. This is the maximum pressure the tyre is rated for before it starts to become unstable and liable to a blowout. You'll have massively reduced traction, and increased tyre wear.

As others have said, your recommended pressure can be found either in the driver's door jamb (near the catch where the door lock clicks on to), or inside the fuel filler cap (German cars like to do this).

On the sidewall of your tyres will be the tyre's size. It is recorded as (for example) 205/55R16. The first number is the effective width of the tyre in mm, the second number is the tyre sidewall as a percentage of the width (55% of 205mm) and the third number is the diameter of the metal wheel in inches.

All you need to do is match that number to the number on the sticker or in the manual. If it's only ever you or maybe one passenger in the car use the lower of the two indicated pressures. If you often drive fully loaded with passengers or with heavy items in the boot use the higher of the indicated pressures. Make sure you use the right pressures for front and rear as they're often different.

Pressure is often given in PSI, but it may be given in bar or kPa as well. 1 PSI = 6.9kPA = 0.07 bar. Remove your dust caps as soon as you park up in the air pressure bay. When you walk up to the machine set your pressure first - they're often in PSI as standard but if you press and hold the unit button it should change to bar. Set the pressure you require. Insert your money (usually 50p) and then once the compressor starts up, hold the wand to each valve stem until the machine beeps at you. It will automatically release air if the pressure is too high so don't worry about that. Once you're done don't forget to put all your dust caps back on. You can easily do all four tyres in the time it gives you - you should probably check the pressure on your spare tyre as well. It's usually higher so check the manual for that pressure too.

Once you've done it a couple of times it's very easy.
Reply 4
Original post by Aky786UK
Hi,

My car tyres are on the low side it seems, and I've never been to a petrol station to use their tyre pressure pumps and wondered if anyone could give me a quick explainer on how to use them correctly (motoring newbie here..)

Also, I've checked my car tyres to see if it gives an idea of how much to inflate them by and as they are all different manufacturers, it seems tricky to ascertain. My manual gives a list of how much to add for different tyre sizes, but I'm confused.

Any pointers gratetfully appreciated.

Thank you

Everybody's already said all there is to say.

The pressures will also be in you car manual - mine aren't on my door or cap for whatever reason.

If you have to travel a distance to get to the petrol station, your tyres will have warmed up, and the air inside expanded. I usually increase my PSI by about 2 or 3 because of this, so 29->32, and 35->38 but that's up to you.Your manual might say what to do in this situation.
Reply 5
You can also get compressors to keep in the car. I've had one for years. Inexpensive and very handy.
Reply 6
Original post by Nuffles
Do not use whatever pressure you find on the sidewall of the tyre. This is the maximum pressure the tyre is rated for before it starts to become unstable and liable to a blowout. You'll have massively reduced traction, and increased tyre wear.

As others have said, your recommended pressure can be found either in the driver's door jamb (near the catch where the door lock clicks on to), or inside the fuel filler cap (German cars like to do this).

On the sidewall of your tyres will be the tyre's size. It is recorded as (for example) 205/55R16. The first number is the effective width of the tyre in mm, the second number is the tyre sidewall as a percentage of the width (55% of 205mm) and the third number is the diameter of the metal wheel in inches.

All you need to do is match that number to the number on the sticker or in the manual. If it's only ever you or maybe one passenger in the car use the lower of the two indicated pressures. If you often drive fully loaded with passengers or with heavy items in the boot use the higher of the indicated pressures. Make sure you use the right pressures for front and rear as they're often different.

Pressure is often given in PSI, but it may be given in bar or kPa as well. 1 PSI = 6.9kPA = 0.07 bar. Remove your dust caps as soon as you park up in the air pressure bay. When you walk up to the machine set your pressure first - they're often in PSI as standard but if you press and hold the unit button it should change to bar. Set the pressure you require. Insert your money (usually 50p) and then once the compressor starts up, hold the wand to each valve stem until the machine beeps at you. It will automatically release air if the pressure is too high so don't worry about that. Once you're done don't forget to put all your dust caps back on. You can easily do all four tyres in the time it gives you - you should probably check the pressure on your spare tyre as well. It's usually higher so check the manual for that pressure too.

Once you've done it a couple of times it's very easy.


Thank you

Looking at one of my tyres it definitely needs a full pressure job but the other tyres could benefit from a snall incremental boost but how would I decide how much pressure to set it up for? don't want to overinflate.
Reply 7
Original post by Aky786UK
Thank you

Looking at one of my tyres it definitely needs a full pressure job but the other tyres could benefit from a snall incremental boost but how would I decide how much pressure to set it up for? don't want to overinflate.

As others have said, your recommended pressure can be found either in the driver's door jamb (near the catch where the door lock clicks on to), or inside the fuel filler cap (German cars like to do this).

On the sidewall of your tyres will be the tyre's size. It is recorded as (for example) 205/55R16. The first number is the effective width of the tyre in mm, the second number is the tyre sidewall as a percentage of the width (55% of 205mm) and the third number is the diameter of the metal wheel in inches.

All you need to do is match that number to the number on the sticker or in the manual. If it's only ever you or maybe one passenger in the car use the lower of the two indicated pressures. If you often drive fully loaded with passengers or with heavy items in the boot use the higher of the indicated pressures. Make sure you use the right pressures for front and rear as they're often different.
Reply 8
Hi,

I'm in a slight panic as I went to the tyre pump this morning to boost my front tyres and they seem worse than before I went in! I did everything as I normally did however on the machine I noticed, it gave me a first number (6) then it changed to E1? It did this on both tyres as I was trying to put air in them. As I said, they look worse for having tried to put air in, not sure what's happened.

Thanks
Original post by Talon
You can also get compressors to keep in the car. I've had one for years. Inexpensive and very handy.

If you are that worried, buy a cigarette lighter socket powered air compressor with an automatic pressure cut off.

I’ve got one, its so easy to use. Set the pressure you want on the compressor, press start and it will inflate it to the set pressure automatically. No need to faff around at a petrol station, feeling pressured because of the shut off timer, people queuing behind etc.

Plus petrol station air pumps can be inaccurate because they get a lot of abuse, run over etc. I wouldn’t trust them. I brought a battery powered tyre pressure checker for spot checks. I use that to check my pressures once a month. If low, the compressor comes out for a quick inflate.
Running low tyre pressures on the motorway can be fatal. The tyre will deform a lot more than usual, stressing the belts inside and causing it to overheat. You can then get a blow out and you might not be surprised to hear controlling your car on 3 tyres at 70mph is almost impossible. Correct tyre pressures are vital for safety.
Reply 11
Original post by Aky786UK
Hi,

I'm in a slight panic as I went to the tyre pump this morning to boost my front tyres and they seem worse than before I went in! I did everything as I normally did however on the machine I noticed, it gave me a first number (6) then it changed to E1? It did this on both tyres as I was trying to put air in them. As I said, they look worse for having tried to put air in, not sure what's happened.

Thanks

6? 6 what? PSI? Bar? I would hope neither of those!
Reply 12
Original post by IWMTom
6? 6 what? PSI? Bar? I would hope neither of those!

I do my tyre pressure with PSI so would assume it's for that. 6 appeared, then it went to E 1 after that.
Reply 13
Original post by Aky786UK
I do my tyre pressure with PSI so would assume it's for that. 6 appeared, then it went to E 1 after that.

E1 is an error. Use a different pump.
Reply 14
Original post by IWMTom
E1 is an error. Use a different pump.

Yeah, I will do. Just not sure why my tyre pressure decreased as I was doing it?
If there was a problem with the valve then the pump may have let more air out than it was putting in.
Reply 16
Original post by Aky786UK
Yeah, I will do. Just not sure why my tyre pressure decreased as I was doing it?

The pump was defective.
Original post by Aky786UK
Hi,

I'm in a slight panic as I went to the tyre pump this morning to boost my front tyres and they seem worse than before I went in! I did everything as I normally did however on the machine I noticed, it gave me a first number (6) then it changed to E1? It did this on both tyres as I was trying to put air in them. As I said, they look worse for having tried to put air in, not sure what's happened.

Thanks

Faulty pump. E1 is definitely an error code.

Get yourself a tyre inflator that you can carry around in your car. That way, should you suddenly discover a slow puncture or something, you can at least pump the tyre up there and then and limp the car home.
Original post by relivemyyouth
You can then get a blow out and you might not be surprised to hear controlling your car on 3 tyres at 70mph is almost impossible. Correct tyre pressures are vital for safety.

Almost impossible is a bit of a stretch, though I think it really depends on the nature of how the tyre goes.

And yes, I've had the unfortunate experience of having to do that. A lorry drifted over as I was overtaking him at a set of (at the time) unused lights doing 70... I was paying more attention to what he was doing after noticing he was drifting over a bit and didn't notice I had done the same, clipped the kerb and put dents in both the front and rear rim. The front rim was bent so much that the tyre instantly deflated.

Let's just say the lorry driver wasn't particularly pleased when I was slowing down having just overtaken him.
Original post by Aky786UK
I do my tyre pressure with PSI so would assume it's for that. 6 appeared, then it went to E 1 after that.

I hope it was just a bad reading, cause my god...Surely you'd notice a tyre that low.

Eyeballing it is a pretty poor way to go about it tbh. It vaguely works on the wheels carrying more weight (so usually the front). But for those that aren't? Largely useless unless the pressure is ridiculously low. There have been odd times where I've, admittedly, neglected to check the pressure for a while and I've come to the back tyres, which look perfectly fine and appear well inflated. Only to find they're sitting at like 1.3 bar (1.8 recommended, though I usually run them at 2.0)
Reply 18
Hi,

Sorry to dig up this thread but my query is relevant, my wife is asking for recommendations for my own birthday gift (it's fine, not fussed about the day tbh) but was looking at a tyre inflator to keep in the car.

Are ones that are decently priced, easy to use that folks can recommend?

Thank you
Original post by Talon
You can also get compressors to keep in the car. I've had one for years. Inexpensive and very handy.


I havent got one myself but i know people who have and yeah they are qute handy.

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