What tyre pressure do you run at?

[GreyRex]

Hi everyone,

Can't really remember a thread about this and thought i'd see what people comments are on this topic. I've got 17's on my SRi Barina and run them at about 33/34psi. I went to a tyre place recently and he said to run them at 40... so now im confused. I know its more subjective than anything and depends on your car and driving style, but what do we all think? This guy said obviously they'll ride harder, but they'll last longer. Any comments welcome

[MatsHolden]

40 all around for my 17's mate. Main reason is so that if i get a puncture i have a little more time to notice it before the tyre side wall is rooted, and that's what the bloke at TyrePower reccomended; where I got my wheels and tryes from. I always ran the 15's at 38 anyway, I never take any notice of the factory placard because they are always for best comfort.

[PaulyJ]

I run mine at 36 all round, but maybe i'll put some more pressure into them now.

[Calibrated]

uhm..i have no idea what the conversion is..

i ran my cars at 2bar - 2.2bar. depending on where i was going, load, etc..

for the drags i dropped the front wheels to 1.7bar..

[oneightoo]

1 bar = 14.504psi at sea level

therefore,

40psi = 2.758 bar
38psi = 2.62 bar
36psi = 2.482 bar
33psi = 2.275 bar

1.7 bar = 24.656psi
2 bar = 29.008psi
2.2 bar = 31.908psi

[oneightoo]

bar is used mostly with weather readings. psi is mostly used for other pressure readings.. in australia that is..

[dieselhead]

i run at 38 psi front and 35 psi rear. tyres are 225/40/R18. a good compromise between comfort and handling imho.

[Deighty]

Hi everyone,

Can't really remember a thread about this and thought i'd see what people comments are on this topic. I've got 17's on my SRi Barina and run them at about 33/34psi. I went to a tyre place recently and he said to run them at 40... so now im confused. I know its more subjective than anything and depends on your car and driving style, but what do we all think? This guy said obviously they'll ride harder, but they'll last longer. Any comments welcome


Have an Astra SRI T - 17's with 40psi all round. Seem to wear very evenly. No problems. Have had 40 psi all the time. Owned the car since brand new for 3.5 years. :)

[Bill_G]

I'm running 38psi all round on my Vectra-B V6 hatch with factory alloys and 205/60/R15 Goodyear Eagle GAs. The ride's a bit harsh, but with -1 degree of camber (negative) it handles exactly the way I want it to at highway speeds.

[luvpsi]

i run 40 on the front and 38 at the rear. The tyres are 215/45/17

[btm]

i run 36 front and 34 rear on my stock SRi 16s

[Vectracious]

Been running 40 all round on a number of cars for a number of years - yes the ride is harder, but the improvement in handling outweighs that, especially in the Astra where the higher profile (stock) tyres will flex on the sidewalls more...

[GreyRex]

Guess I was out of the loop on this one. Will go and put the extra psi in them when I can. Be interesting to see what difference there is:)

[woody]

i run 36 front and 34 rear on my stock SRi 16s


Same - stock Sri 16" - Same pressures as BTM - seems to give best performance for grip/fuel without compromising the braking capability or ride.

[woody]

Guess I was out of the loop on this one. Will go and put the extra psi in them when I can. Be interesting to see what difference there is:)

don't go too high or you'll start to notice the wear in the centre of your tyre is higher than the edges, this is because the tyre will start to baloon in the centre the more pressure you put in. the best balance for general driving is when the full span of the tyre is in contact with the road without too much sag - sag, ie a low pressure in tyre will cause excessive wear on the edges of the tyre and also decrease your fuel economy.

Run hard tyres for track or drag, soft for sand and mud medium for road.

[Bill_G]

Nobody, including myself, has so far mentioned that tyre pressures need to be checked while cold, which may be a tad difficult if you've just been driving around on them, as pressures increase substantially when the tyres are hot.

The easiest way of overcoming this problem is to overinflate all four tyres by around 5psi just before getting home, then wait for several hours until the tyres have cooled to ambient temperature, and release the excess air until the pressures are correct.

[WLD-18L]

in my 215/45/17 i run 36 allround.

im lucky enough to own a air compressor

[woody]

Nobody, including myself, has so far mentioned that tyre pressures need to be checked while cold, which may be a tad difficult if you've just been driving around on them, as pressures increase substantially when the tyres are hot.

The easiest way of overcoming this problem is to overinflate all four tyres by around 5psi just before getting home, then wait for several hours until the tyres have cooled to ambient temperature, and release the excess air until the pressures are correct.

Very good point there Bill. if you drive lazily from your house to the local servo (within 5 k's) and you started off with cold tyres, you'll be within 1/2 a psi of the cold pressure when you get there.

[dustbug]

Running 40psi on my 20's, i may try something a bit higher next time i fill up with air, maybe 42/44psi. 225/30R20

[Bill_G]

Very good point there Bill. if you drive lazily from your house to the local servo (within 5 k's) and you started off with cold tyres, you'll be within 1/2 a psi of the cold pressure when you get there.I expect that's probably true at night or when it's raining, but when the road surface is hot enough to fry an egg, as it usually is in Brisbane at this time of the year, I strongly suspect that the tyres are going to reach their operating temperatures very quickly indeed.

Nevertheless, Woody, you make a rather interesting point and I'm sufficiently curious that I'll test that hypothesis around midday tomorrow by periodically recording my tyre pressures over a distance of 5km or so, then I'll post the results here.

[EL BURITO]

42PSI all round on my 17's

[dieselhead]

42 psi! this thread started to look like an ebay auction guys :D
isn't that too high? i know a 20" would be ok at that pressure, but a 17"? just asking here, not telling...

[PaulyJ]

I got 205/45/R16 on mine, and now running 40psi after reading this.
Feels a little different, but not much.
Might need to go thru some proper corners to determine if there was a diff.

[cyclonic]

I always run at the maximum that my tyres are listed for on their sidewall. Read your tyre, find the max pressure than drop back a little from that, unless you're looking for good fuel economy.

[AF1R]

SRi-T stock 17's> some of u guys are running 40psi all round and some running higher for the front than for the back>>
What are the advantages and disadvantages.

[Bill_G]

Higher pressures = longer tyre life and better handling & fuel economy, but a harsher ride.

[Tfer]

Running 235/45/17's on the Veccy C..... and 40psi at all four corners. After a service, first thing I do is head to a servo, get out my own tyre gauge, and reset the pressures (bastards always lower the pressures) :D

[woody]

Some basic tips

Do not check the air pressure when the tyres are hot.
For high speed driving, add 3-4 PSI.
Valve cores & valve caps should be tightened properly to prevent air leaks.
Both tyres per axle should have the same air pressure but may be different front to back.

Overinflating your tyres will increase central tyre wear, front to rear should normally be different unless you have a 50 50 balance car. This is to compenstate for the weight of the engine. Your manufacturers plaquard for tyre pressure is set for comfort - read the plaquard and if you perefer a higher pressure use the guide for load/highway driving +3 Psi that should be sufficient for the fuel benefits without compromising on the effectiveness of the tyre or increasing wear.
Check the tyre pressure at least once a week.

[dustbug]

If you put too much pressure into your tyres you will get all tyre wear to the centre on your tyres while if you under inflate your tyres you will get tyre wear on the inside and outside of your tyres. Best is to go for the perfect presure.

Notice your side tyre walls max presure is for a fully loaded car of 5 passangers and luggage in the boot.

[pred8r]

34 for the Corsa (17"s)
70 for my van :eek::eek::eek: (TRY to find somewhere that goes that high:mad:)

[skulless]

first of all, sorry to bring this old thread out, i've been studying the tyre pressure threads for the last hour.

imho, the best psi to run on a 17s is 38/36. my tyres are 205/50/R17, i do not know why it isn't the 215, anyone care to enlighten me? I got the stock rims that came from the astra twintop.

another link i found on googgling:
http://www.thetyrepressuremonitor.com/tyrepressures_vauxhall.html

[JR]

i'm running 36psi on my 215/45/17s. i usually check mine once a month - when the tyres are cold.

my dilema though is my friggen tyre valve caps keep getting stolen!!!! MOFOs!!!
i had nice chrome steel valve caps - all 4 got stolen.
i put el-cheapo plasti valve caps - 2 got stolen
i put nice gray steel valve caps - all 4 got stolen.

now i got no valve caps :(
is there any lockable versions u can buy?

cause i think my tyres r bleeding air through the valve, cause everytime i check my pressure, they've dropped 3-5psi.

.

[kaoshunter]

i'm running 36psi on my 215/45/17s. i usually check mine once a month - when the tyres are cold.

my dilema though is my friggen tyre valve caps keep getting stolen!!!! MOFOs!!!
i had nice chrome steel valve caps - all 4 got stolen.
i put el-cheapo plasti valve caps - 2 got stolen
i put nice gray steel valve caps - all 4 got stolen.

now i got no valve caps :(
is there any lockable versions u can buy?

cause i think my tyres r bleeding air through the valve, cause everytime i check my pressure, they've dropped 3-5psi.

.
They have lockable opel valve caps on ebay
Here a link:
http://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&rd=1&item=120141296441&ssPageName=STRK:MEWA:IT&ih=002

I don't know how good they are though but they lock in by an allen key grub screw

[R3N]

don't forget that the same tyre pressures aren't something that can be applied to all vehicles. depends on what you want. the user's manual usually gives you a good indication of what it should be but at the end its up to the driver to decide for themselves.

more pressure = better handling, more feedback
less pressure = more grip

too high or too low and you get uneven wear

[skulless]

yeah i know diff ppl has diff opinions...i saw lots of ppl on 40 front 38 rear on most 17s..then i saw a couple on 38/36 as well...so i thought i wanna try mine on 38 n c how i run

oh i forgot to add, mine is the bridgestone potenzas, it says max 50 psi

[bigmick]

i always check pressures when cold....always run 36 psi all round....stock 15's...checked at least once a week...

[Mane]

2,6 bar in front and 2,4 bar in rear as recommended from Opel in my OPC with 215/40/17, since 60000km smooth wear of the Dunlops.

Too low pressure may dangerously heat up your tires if you drive at high speed.

Lg, Mane..

[digifish]

Nobody, including myself, has so far mentioned that tyre pressures need to be checked while cold

If they are already warm/hot and you inflate to 40 you won't go far wrong.

digifish

[Vectracious]

The manual / manufacturer always recommend a less than optimum pressure to improve ride comfort over handling. I've been running 40psi all round when cold in every car I've owned and find it to be the best.

[bornwild]

34psi front, 32psi rear

[kz_11]

generally, wht do you guyz recommend for a astra H CD with the stock 15' alloy?

[digifish]

generally, wht do you guyz recommend for a astra H CD with the stock 15' alloy?

38 all round.

digifish

[skulless]

i just bought a digital tyre gauge and my tyres show at 39 when cold. this makes me think maybe i should pump my up to 40 front and just leave the rear at the same. and when i'm on highway, i'll go up to 42/42...

[MatsHolden]

i just bought a digital tyre gauge and my tyres show at 39 when cold. this makes me think maybe i should pump my up to 40 front and just leave the rear at the same. and when i'm on highway, i'll go up to 42/42...

Just check what the tyre's max psi is on the side wall...

[nicecar]

What is more dangerous and could cause a blowout? under or over pressure?

[R3N]

What is more dangerous and could cause a blowout? under or over pressure?

i'd say under if you were doing prolonged periods of high speed driving

unless you're referring to the max pressure... in that case over = bad

[skulless]

Just check what the tyre's max psi is on the side wall...

it says 50

[cbrmale]

I run 250kpa on my AH SRi with 225/45 on 17 (the placard recommends 210 or maybe 220, which is too soft). I don't know what that equates to, because I remember metrics were introduced to Australia when I was in high school (which is a long time ago). I think it is less than some people here, but any higher and the tyre loses flexibility to cope with smaller imperfections on the road surface (ie - it skips around on small harsh bumps). From experience with my previous car which was a similar weight to the Astra, 250 will give even tread wear and no problems on long drives at speed.

On my wife's XC Barina (185/55 on 15), I run 240 which gives very even tyre wear.

[Tfer]

The manual / manufacturer always recommend a less than optimum pressure to improve ride comfort over handling. I've been running 40psi all round when cold in every car I've owned and find it to be the best.

Same.... ;)

[guy 27]

36 all round when tyres are cold otherwise 34 when warm.

I have nice silver bullet caps. one has been stolen but i got 5 so had one spare.

My tyres tend to go down about 2 psi a month which is normal wear

[immenotu]

38psi cold all round in 205/40ZR17's on my Corsa SRi. I use nitrogen tho, not air. Arguably better and get it topped up for free. Hard ride but love the handling.

[bornwild]

What is the advantage of having nitrogen compared to Air....if they're at the same pressure?

As for the kPa to Psi....250kPa is roughly around 35ish Psi.

1Bar=14Psi=100kPa=1atm(easiest way to remember it) :)

[immenotu]

The nitrogen doesn't expand as much as air when it heats up due to no water molecules so the pressures stay more even and give better wear, and the tyres run slightly cooler at speed (not a big difference).

Because there are no water molecules in there you also dont have to worry about the inside of your wheels rusting, good if you've spent a bit on your wheels. Other advantages too...

http://www.toyo.com.au/tech_info11.html

This explains it pretty well.

[cbrmale]

Pressure build-up when the tyre is hot is a factor to consider. I check my cars in the garage early mornings. Given Canberra's cold mornings, by mid-afternoon in the garage the 'cold' pressure has risen by 10kpa to 260. Park it in the sun for an hour and the 'cold' pressure has risen another 10kpa to 270 (which is about as high as I want to go).

[shadow]

36/33. 2002 barina sri, 17'' stock alloys

I used to put in about 32/31, but the tires wore out significantly more on the outside, so it means they were underinflated...

The right pressure is whatever wears the tires out evenly... that way the tires is evenly in contact with the road, meaning you make the most of the surface area of the tire in contact with the road...

I still dont know if the pressure is right, but the instructions on my fuel cap were clearly rubbish because the tires weren't wearing evenly...

[shadow]

(2002 barina sri, 17'' stock alloys)