Out of sheer curiosity... Is it ok to pump more/less air than advised? i am talking about +-2psi more/less.

or must follow exactly as advised?

my new sets of tires seem to be a bit lumpy (?) like not enough air when i follow the psi required, and that is without load. for the record, the tyre brand is different than the stock tyre, but the specs remain.

Many reason tyre become lumpy. Tyre brand, type, load, road condition. + - 2psi still in tolerance. But nvr exceed max advised.

tyre brand different nevermind, size matters. it is best to follow to recommended tyre pressure by car maker. if it is too low, your fuel economy suffers, if pressure too high, car is very bumpy and unstable at high speed, car seems to be floating. side of the tyre patch is not touching the road. very dangerous

usually i pump extra. then slowly release each 1-2day until satisfy.

2 psi more than OEM recommended pressure is ok, as it's way below tyre manufacturer's maximum permissible pressure.
2 psi below would not be ok at designed loads, as it promotes tyre overheating and potential tyre burst at prolonged high speed.
I typically fill air up to 30 % higher than OEM recommendation for agility and better fuel economy with acceptable increased ride harshness.

This post has been edited by zeng: Feb 2 2017, 09:50 AM

30% higher than oem ? wow @@

Let say oem is 30psi so you inflat till 38psi up ?

Recommended tire pressures on the door sticker is also not really accurate or must be strictly followed. It serves more as a starting point for you to adjsut until you find the right one for you. It depends on your preference how you like the car to handle. If you feel the recommended pressures is too hard then can reduce bit by bit but usually don't go too low below 28psi. On the other hand if you feel it's too soft then can also increase bit by bit until you find the sweet spot for you, as long as it's not exceeding the max pressures. Note though over inflating a bit higher than recommended is generally less risky than under inflating it by the same amount coz under inflation can cause heat build up easier during high speeds. That's why I personally almost always inflate around 2-3psi higher than recommended. Over inflating a bit also serves as an extra margin so that when you loose pressure you will still arrive at around the recommended pressure and not too low below it.

That's right, up to 30% overpressure.
Wira 1.5 recommends 29 psi all round . Mine is 37 psi.
Had been monitoring for several years, no premature wear (uneven botak) at the tyre centreline area.

This post has been edited by zeng: Feb 2 2017, 04:28 PM

Mine recommends 32psi front, 29 back. makes sense to have both to be at, say, 32psi? No reasons whatsoever, just a moot idea for discussion.

Usually tire pressure recommendation is largely determined based on the weight distribution. If the car is front heavy much more, then usually the recommended pressures are higher for the front. If you make them even then you may feel the rear becomes a bit jumpy/harsh, unless you have extra load at the back.

Passenger car size 13-14" normally 34 Psi
15-16" " 36 Psi

Above pressure just based on the road condition like highway. This is mostly tyre store did at down under. Of course those particular driver will inflate to suit their handling.

Nooo ......

This ..


This post has been edited by zeng: Feb 4 2017, 10:18 PM

I added 2 more psi than the car manual recommendation. car feels a bit more bumpy/harsh and noisier.

Not sure if it is because I am more aware of it now, or i better to follow the recommended tyre pressure advised by the car manufacturer

If you feel too harsh then just lower it back to std recommendation, maybe that's already the best compromise between handling and comfort.

Depends on weight, take base 32 PSI and 90% drive alone. I usually pump to 33 PSI to compensate for the infamous road conditions in Malaysia.

I guess so too. I revert back to the recommended tyre pressure and see if there's improvement.

Well, most of the tyre store at Vic inflate with that pressure and no complaint received. Tyre also last quite accurate with mileage estimation.

For my myvi 1 psi above recommended is fuel saving.. 2 psi above, the fuel usage increase..

Same, I also pump extra +1 PSI for my car. I don't dare to pump extra too much cause I scare the tyre fly out XD

not more air = lesser contact to the ground = less drag = lesser fuel meh?

How so?? That doesn't make sense.

i know right... i thought like that too thats why i pump a bit more.. but my fuel consumption dipped .. usually i can get about 420 to 450 km per tank but if i pump more air it drops to about 400 km per tank.. tested it over the past year using michelin xm2 tyres .. how about your experience?

Pump 1 more psi should not make much noticeable difference but it also should not make the FC worse. I suspect is more about the driving style or the tires. You need to measure correctly also to really draw a conclusion.

can share your experience with different psi settings and your tyres?

See tire pressures actually also will steadily/slowly go down bit by bit. So for example when I pump 35psi on my car, after maybe 3 weeks or so, the pressures will already drop to around 32psi, sometime more, sometime less. The FC when I was on 32-33psi seems to still be about the same as when I was using 34-35psi, or at least not significant enough of a difference to conclude. However I think my best FC record was achieved when my tires were at 34-35psi. Note that I measure my FC practically every full tank, meaning every time I refill full then divide by distance traveled, so it's real average FC and not based on econometer estimates.

Actually is OK if u drive fast or carry full load 5pax
On my camry the sticker say u can put 210kpa for light load & <160 kmh speed
Increase to 290kpa if for 5pax full load &/or >160kmh speed

So saying if u know ur Gonna ferry five pax then u go inflate the tyre just for this particular journey? After that deflate it again? Or just keep it at 290

Nice info from Camry!
I learned from internet saying for highway travelling (km/hr not specified), increase OEM pressure by 10%.
So I started off upping 10%, now in 30% territory ....
Would appreciate very much if you could upload a picture of said sticker... for general guidance ..... if it isn't too cumbersome for you.

Just keep it there. What pressure that you need to maintain is depending on your most frequent driving condition, don;t need to be so impractical and keep changing back & forth. For example myself, since I often reach highway speeds so then I maintain about 3 psi above std recommended pressure. As I explain also above that this is a precaution/margin too so that if the pressure drops, it will still be around the recommended pressure. In short, use the pressure that suits your driving the most and maintain that. However note that over inflating a bit above the recommended is safer than under inflating as under inflating tends to build up surface heat faster and therefore higher risk of blow out.

Took a shot of the Camry manual instead.
Generally if you drive at higher speed ranges/carry more load you need to adjust tyre pressures accordingly.

Also note these are cold tyre pressures, interestingly some cars (Merc) they specify to add (up to) 4psi for warm tyres, guess that depends on how hard/long you were driving otw to the air pump.

This post has been edited by ceo684: Feb 11 2017, 04:15 PM


Attached thumbnail(s)

Thanks heaps, mate.
Learning something new and authoritative on tyre pressures from your posts .....
I read some tyre literature saying that after parking between 30 min to an hour, one may pump air at indicated OEM cold tyre pressure.
Your attachments are rather detail and specific...
Btw, can I have your prior permission to upload your above pictures in forums like Bitog/lowyat etc for the benefits of others in times to come ?

This post has been edited by zeng: Feb 11 2017, 11:35 PM

Ok noted 👌🏻

Tire size does matter on this , bigger profile means carry more load and overall load .

Based my experience using stock tyre Turanza ER370 (recommended 33 PSI front & 32 PSI rear). All good.

Once change to Ecopia EP200, 33 & 32 PSI somehow increase my fuel consumption, noisy & tyre feel like less air.

Pump up to 35 & 34 PSI. All optimized. They said EP200 compound is softer than average tyre.

For me recommended tyre pressure stated on door side or manual is for stock tyre. Good to follow.

But if change to different tyre brand / model, the optimum air pressure will be different.

not a tyre expert here but then softer compound usually is stickier rite

about the recommended tyre pressure stated on the side of the door is a general guide for the car, as manufacturer have tuned the whole suspension to work best with that kind of pressure. of course it varies by tyre if you decided to stick on a high performance tyre compare with eco tyre that manufacturer are using.

the number there is for mass user who will be opting for similar tyre size and range

Am I the only one who look at pascal unit? I can't seems to brain psi indeed.

I would add another 5% or less of air pressure due to the OEM instruction is based on cold tyre. By the time you get to gas station you will have hot tyre.

This post has been edited by therain01: Jun 28 2017, 01:57 AM

is the recommended psi is based on cold tyre if itz not stated on the sticker?
if so, when we inflate warm tyre, how much psi should we add?

Think so.

My benchmark is fuel consumption. Noise level & comfortness are subjective for me. Based on car insulation too.

By right, eco tyre should use less fuel than non eco tyre.

by right eco tires should use less fuel than non eco tires as the rolling resistance is way lower thus reduced the need for more power to push the car move.

but then if pair with eco tires and yet your golden right leg still stomp the fuel pedal like normal then is still going to be same

in addition, to achieve better FC with eco tires is actually let the car glide more.

This post has been edited by herojack41: Jun 29 2017, 04:42 PM

A tad clarification on the bold phrase pls. Do you mean the exact tyre the car came with when it went out the car dealership,
or do you mean that the manual states the tyre pressure for tyres of the same range/size?

My understanding will be OEM tyre. Tyre originally fitted in upon purchasing the car.

I don't think same pressure applicable with tyre with same range / size. Unless exact same brand, size & model.

Eventhough same range / size, different tyre manufacturer or even different model will be using different compound, soft / hard sidewall, etc. That contribute to optimum tyre pressure.

Not so expert lah. Based on my experience & reading only.

Unfortunately I beg to differ on this.

This post has been edited by zeng: Jul 2 2017, 01:20 PM

like for avanza in the manual only said front 210kpa rear240kpa, it did not show any load or no load condition just a table stated this pressure.
so follow it?
also the tyre change from stock 185 65 r15 to 195 60 r15
so thr tyre pressure how now?

I believe these two tyre sizes 'happen' to have the same load index, therefore same OEM recommended tyre pressures for both front and rear would be applicable.
However in my 1.3 Avanza, I select over-pressure of 275 kpa in all 4 tyres for agility and fuel economy.

This post has been edited by zeng: Jul 13 2017, 10:19 PM

275kpa for avanza is just too much man

Yes, it's on the high side for Avanza's weight and it's recommended 210 front 240 kpa rear.
But, it's way below the tyre's maximum allowable weight/air-pressure of 310 kpa.
No uneven tyre wear though.

how do i know how much psi need to pump in...
which label to check on my tyre. is it written on my tyre

it is not written on the tire.
it might has a label stick behind the fuel door. then you might refer to the recommended pressure for different tire size.
i believe you can check the recommended pressure inside your car manual booklet as well.

you can provide your tire size and sifus here will recommend you instead.

hi guys. bought a new saga with 15 inch wheel just for a week,

yesterday i thought the pressure in the tire is less so went to petrol pump to fill the air. the shock is the air tire pressure was already 40psi. i have only change to 33 psi to both of front tires only but not at back since i am confuse. the maximun load on the tire is 44psi if not mistaken.

do i need to change the pressure on the back tire as well? first time owning a car here.

Without knowing further details from your car and tyre size, all four tyres on 40 psi should be ok for agility and FE.
All four tyres on 33 psi should be fine too.

My wira calls for 29 psi on all four, but I pump up to 37/38 psi for agility.

this is my tire specs is 185/55R15 and the tire is Good Year but forgot which model. i checked yesterday the max load is 51psi and not 44psi as i mention. so i went to petrol pump to check my tire pressure.

the tires is still cold so when i checked the pressure is 240kpa, not sure what the psi is haha. so i put all my tires to 240kpa.

i was confuse because the guide at the door stated 210kpa for front and 20kpa at back during cold tires. just that even i put 240kpa, the tire look like inflated like not enough pressure. is it ok for tires to look like that as long as the pressure is enough?

240 kpa is ok for your car, that specifies 210 kpa for front and 220 kpa for rear.
These tyres could go up to 250 kpa if you wish, up to 160 km/hr.

Hi All,

My tyre is written with Max pressure 350 KPA 51 PSI

May I know what is the recommended air?

My tyre brand is continental CC6

Thanks.

I'm running 210kps front & 200kpa back. RWD corolla.

My wira 1.5 (and Avanza 1.3) tyres are rated at maximum pressure of 51 psi too.
Proton specifies 29 psi for front and rear in Good Year 75/70R13.(Refer to driver side door pillar).
I had been applying 37-38 psi tyre pressure for umpteen years with good results.

There is no so called RIGHT when it comes to air pressure. After all, air expand and compress when subject to different environment.

Just play around with the figures until you get what you want. 30PSI is just nice but you will need to pump it really often. Different tires profile and design will react differently. Like those eco tires which are usually thick and with soft tirewall, you will feel much better under braking if you over inflate them but if you overdid them, it felt like riding a horse when going over those yellow lines. Just try and feel for it yourself. Everyone has different taste.

Usually I pump 32-33PSI for the best of both world. Not too hard, not too soft.

There is this maximum pressure allowed, indicated on the tyre wall. It makes sense not to pump air to this 'maximum pressure', right?

Yes, one should not pump air to the maximum pressure indicated, as like 51 psi for some tyres.

The door sticker on my Elantra 2002 recommends 210/230 kPa. When I was using old tires anything above 240 kPa will cause road surface and tire noise more noticeable . But after change new tires now I pump 260 kPa still smooth ride.

I pump all my 82H/88H tyres up to 280 kpa/ 41 psi for fuel economy and agility.

How much would the air pressure increases if driving for long hours during the hot day? It should be about 4-6psi?

How much would the air pressure increases if driving for long hours during the hot day? It should be about 4-6psi?

My rule of thumb is about 4 psi.

So if max allowed is 51psi, max air pressure can put is 47psi. Anyways, 40+psi is already on the high side dy. I usually pump 31front/28back.

Will try pump more and see the effect on driving/braking

Update on my earlier post...

I pumped 34front/32back.

Car feels more agile, but rattles/shakes more. Braking distance increases, and feels less safe (lesser contact to ground?). Fuel economy-wise, hard to guess. Macam no significant difference

For sedan, does it make sense to pump same air pressure for both front and rear?

My Avanza specifies 31 front and 35 rear.
I pumped 38 psi, and now 41 psi on all four tyres ...........................
for its maximum tyre loading and maximum tyre road speed which isn't required for the Avanza, but fine for the tyres anyway.

This post has been edited by zeng: Feb 21 2018, 10:52 AM

Must be epic bouncy

What are you aiming for in pumping more than the recommended air pressure? Is it fuel economy and/or lesser frequency to pump air and/or fuel economy? Curious to know

More for agility ... and then for fuel economy, yet stay within specs of tyres in question.
Also note tyre pressure drops by about 3 psi in every 1-1.5 month of use .

... not really with good road surface in KL/Subang Jaya areas, other than safety bumps within Taman where I typically move at 15-25 km/hr.

Fair enough. Anyway, no significant longer braking distance?

Longer, yes.
Significant, no .

u want comfort, u pump air near to oem spec (always more, never less than oem spec)

oem pressure is their tested pressure which gives best comfort without sacrificing performance (or issit the way around, forgot). usually la.

u want best performance, u pump higher pressure, but never exceed max load pressure by tyre manufacturer. u need to find the best sweetspot for ur car. meaning experimenting urself. theres no 'one pressure to rule em all' for this. deswai race car oso need to find their right tyre pressure for every track, sometimes right pressure means 1-2 sec difference in lap time.

higher pressure gip better performance (grip, fuel economy, less rolling resistance (last one im not sure ) but ull be sacrificing alot on comfort.

This post has been edited by kurangak: Feb 22 2018, 08:47 AM

Maybe the additional ride height/suspension travel mask the harshness quite well.

I did something similar to my sedan, quite close to maximum recommended, and the car feels like it was on adjustables set to harder setting. So i dial down 10-15kpa for my preferred setting.

Less rolling resistance and better grip? Wont less rolling resistance means less grip?

If manufacturer recommends 32front/30back, make sense to put front/back to 32psi?
Both front/back tyres same size

Yes if you are carrying passenger + luggage.

Mine front and rear ate diff profile but I pump same 35 psi! The car feel lighter. Lol!

! What's your tyre profile? Most is 15 inch rite ? 38 psi?

185/70R14 88H tyres.

i always pump according to the spec but that figure can only be used when its cold and the pump station 1km or less than the first time the car start moving...

if u already drive the car in a hot day noon/afternoon...always pump up 20-30kpa higher...

let say the figure at the driver door stated 200kpa...then at afternoon please pump 220kpa or 230kpa as the pressure will become lower at night when cold and become +-200kpa...

if u pump 200 in a hot day noon...at night it will become +-170 and the tire be underpressure

if at the driver door didnt stated to pump up more if car is full load then it isnt necessary...

my car stated that i have to...if normal usage 4 people and few luggage need to pump 210kpa when cold front and back...if 5 people and full luggage in bonnet have to pump when cold 230kpa front...290kpa in rear...

my other car stated drive below 160kph pump 210 front and rear...if intend to drive more than 160kph need to pump 230 front and 260 rear...

so...in my opinion...follow the pressure recommended by the manufacturer...lil bit more still ok...and always pump up 20-30kpa more in the afternoon after u have drive ur car for a while as the pressure will become lower at night when the tire cold

This post has been edited by spadecrew: Mar 10 2018, 04:36 PM