tyre pressure

[sunflower]

I'm taking my car on holiday soon - fully laden with 4 people & luggage

How much do I need to increase each type's PSI by

[Dave Brand]

Originally posted by sunflower
I'm taking my car on holiday soon - fully laden with 4 people & luggage

How much do I need to increase each type's PSI by

Read the manual!

[medler]

From my observation of people going on holiday in their cars, these seem to be the standard pressures.
Left front 32psi right front 25psi and cutting out on the edges, left rear 25psi and right rear less then 10psi, spare should be flat and illegal. If you have a caravan then those tyres should not exceed 15 psi and should be severly perished.

[garcon]

Yep, follow medler's guidelines and you should be fine

Alternatively, do as Mr Brand says and R T F M !!

Failing that, ideally you should probably increase by around two psi, though depending on the car it'd probably be fine unchanged (assuming they're anything close to correct to begin with...)

That reminds me - must check tyre pressures/oil in themorning...

[sunflower]

I wish I hadn't even bothered posting this when all I've got are nasty replies!!!

If my manual gave the info I wanted, do you not think I wouldn't have had to ask.

Don't be so critical

[bella]

what they meant to say () was it really does depend on your particular car as much as it does normally. if it doesn't say, you need to ask a dealership if they can help out. and remember once you get there to change the pressures back if you're worried about tyre wear.

[Airhead]

yes read the manual then add about 4 lbs/psi.

Because they give advice that is under the appropriate pressure to ensure a good nice comfy ride.

By increasing yor tyre pressure you will save fuel, save money on tyres (they last longer) and increase your handling in the dry.

[Bluebottle]

Sunflower, I posted a reply before your second post which seems to have gone missing! I came to your defence by suggesting that perhaps you didn't have the handbook, ah well, I tried

Moffy, I wore out a set of tyres on my Granalcon because I didn't lower the pressure during a summer interspersed with fully laden + trailer and solo driving up the M1 to work and back!

[carrera]

Many cars have a tyre pressure setting guide stuck on the B pillar.

[Dave Brand]

Originally posted by sunflower
I wish I hadn't even bothered posting this when all I've got are nasty replies!!!

I had no intention of being nasty.....just stating the obvious, really.

If my manual gave the info I wanted, do you not think I wouldn't have had to ask.

If the manual doesn't give the information it's because it's not necessary.

[garcon]

Sorry Sunflower - didn't mean to be nasty.

It's just that I work with lots of techies in IT, and time and time again the last thing they resort to after days of trying to rebuild a system from scratch is to read the manual. Then they find something obvious they should've done in step 2...


Ah well.

For most of the cars I've owned, the manual suggests adding around 2 psi if you're travelling fully laden. I tend to keep it around that level anyway (when I actually bother checking! )

[noise boy 2]

I seem to recall reading somewhere that you should increase tire pressures 4psi for extended high speed (freeway here in the USA) driving, but I can't remember where I read that. Robert

[Flatspot]

Personally I would just inflate your tires to the max. pressure printed on the side of the tire. Its all there in little letters. Something like "Max.Pres.42PSI" This is better than the manual (you don't have) anyway. Especially if you are not running the original tires that came on the car. Do this when the tires are cold (first thing in the morning before you've gone far) as they will build a little pressure on their own as they heat up.

Have a great trip!

[Dave Brand]

Please, for your own safety ignore the bad, even dangerous, 'advice' you have been given in this thread.

I will reiterate: read the vehicle handbook, or the tyre pressure sticker on the vehicle, & inflate your tyres to the pressures recommended by the manufacturer. If the manufacturer does not recommend higher pressures for fast driving/heavy loading it is not necessary.

Inflating your tyres to the maximum pressure shown on the tyre wall will give, typically, 50% overinflation above the recommended pressures......a car in this condition is dangerous.

The vehicle manufacturer knows more about your car than any well-meaning 'experts'. Manufacturers can't afford to give bad advice - they are the ones who will be facing the product liability lawsuits if things go wrong.

[BertMk2]

I'd agree with the above - if in doubt just check with your local main dealer, they'll be able to give you any info you need regarding tyre pressures (don't forget the spare!).

It's worth double checking the condition of your tyres before you leave as well - worn tyres and unsightly bulges aren't a good idea, better to get new tyres than have a blow out (also 3 points on your licence per dodgy tyre is a bit of an incentive).

[Airhead]

Jesus Dave that's a bit hard core -

4psi over the recommended inflation pressure ain't gunna send anyone into the wall at speed!

[garcon]

True, but Flatspot's advice is dangerous. Maybe that's where he got his name. After all, if it all goes wrong in Slat Lake City, there ain't much to hit...

[Airhead]

The thing with manufacturers maximum pressures is that people don't check their tyres when they are cold. So, to cover this, and to avoid complaints on poor ride performance they usually understate the maximum pressure.

I don't believe that Flatspots advice (42psi) is all that dangerous for radial tyres of a medium profile.

If we are talking cross ply tyres with a high profile - then yes, 34psi will do.

[TimD]

Well, think about this one - the same radial tyre could equally fit a late-model VW Beetle or an early VW Golf. One has a big empty space above the front wheels and is powered at the back, the other has a ruddy great engine slung above the front wheels which drive at the front.

Believe me, pump the tyres up to the tyre manufacturer's maximum tolerance levels and you WILL feel the difference. The Bug will also try to hurl itself at the scenery at the slightest whim, while the Golf will indulge in snap turn-in.

Perhaps if Sunflower could furnish us with the model and year of the car in question, perhaps someone with a manufacturer's service schedule might be able to help.

[Dave Brand]

Originally posted by AMoffat
I don't believe that Flatspots advice (42psi) is all that dangerous for radial tyres of a medium profile.

OK, for my car the recommended pressure are 29 lb/sq in front, 30 lb/sq in rear. In the 11 years I've had it, I've never seen any need to deviate from these figures - the very even tyre wear I get indicates that the manufacturer got it pretty well spot on.

The maximum pressure marked on the tyre sidewall is 44 lb/sq in. That won't affect safety?

[sunflower]

Panic over I've maticulously read my manual again & must have somehow skipped the tyre pressure data page - it was there all along!

I'm not going to hide my head in the sand in shame as I DID read the manual

Normal load - 30 front & 23 back (psi)which I already knew
Full load - 35 front & 40 back

My tyres are 14" radial low profile

[Bluebottle]

Don't worry 'flower, it made for a good thread!!

Have a good holiday, and drive carefully

[Dave Brand]

Originally posted by sunflower
Panic over I've maticulously read my manual again & must have somehow skipped the tyre pressure data page - it was there all along!

It does suggest that the manual leaves something to be desired if such vital information is so difficult to find!

Interesting numbers - what's the vehicle?

[sunflower]

I drive nothing but carefully - believe it or not I've passed an advanced test

My car's a plain, non-sporty, 1.2 current shape corsa.

Within a week of buying it next door's cat sprayed on it & scrapped it's claws along the back bumber (body coloured one) - wasn't too happy about that!

[sunflower]

That reminds me - must ask someone to water my sunflowers