After returning home from hols and a heavily laden vehicle it was time to reduce the tyre pressure. I found myself thinking that I had not seen anybody else doing this, infact it is rare at all to see anybody checking tyre pressure in filling stations.

Do people just not bother or can you get accurate equipment to do this at home?

I realise that if pressure is either very high or very low it would be dangerous but how critical is it to stick to the book pressures?

within a few pounds either side will be fine.
I tend to run mine quite high as i do a lot of motorway driving.

I've never bothered to increase it for a heavy load, but i do check them about once a month.

A few pounds either side should be OK, but be careful if you're carrying a heavy load or...ahem....going at speed.

The other thing is that your fuel consumption will be worse for low pressure, and if you start hearing a 'squek' when you corner your tyre pressure definitely needs checking.

Joe

remember that the only thing conecting you and the car to the road are those 4 small areas of rubber - a car is pretty heavy and can travell relatively fast.
as Cyclone and JoePritchard pointed out a couple of pounds either way wont be to critical.
I check mine prob a couple of times a week - If you do it regular to start with you get used to when they 'might' need checking
the thing to remember is that if to high or low, alters the profile of the tyre in contact with the ground so that it looks (check out sideways on as if a smiley) : ) too much , or: ( to little - both reducing the area in contact - also worth baring in mind is that to low could also affect the tyres adhession to the rim.
all this is just idle chatter till youre carrying a load and someone hits you from behind! (happend to my brother - one of the things that saved the vehicle from being flipped was loading correctly and the other was correct adhession (tyre pressure). (the thing to remember is that it is not your driving skills at test but the stupid ****** who hits you out of the blue.
I learnt as a bike rider where it is maybe more critical (except when there's a person/child walking out in front of you!)but serves just as well for me in car - try a test for yourself (off road off course! :-) ) get to a set speed (something safe like 15/20 mph max) and try emergency stop. Now let some air out and try - notice the extra skid - not too bad on straight but as soon as you try any sort of manouver your ***** especially in the wet!!!
try on empty car park, air field(disused!)etc - there is nothing like leaning for yourself.
go easy
Frankieboy

Thanks you lot for your advice I shall try to be more vigilent.