An interesting article on air pressure & load index

[Ungtiong]

my car recommended is 210kpa COLD..which is around 220-230 when we go pump at the petrol station. Pump hot day or cold raining night also got difference...also if u park ur car outside in hot sun for a long time liao also got difference...

[Cheridan]

thanks all, learnt a lot from this thread

[Cluboxed]

impressive article...

[Wormvirus]

after work no math will get in the head

[Mustang]

I'm still lost why some bread and butter mpv must use 19 inch with side profiles as low as 35 series when everytime they're carrying full loads?Unless your car on steroids I dun see the need to upgrade till 3-4 inch higher..

[Tyrequeen]

Interesting article :) Kudos to you for the technical stuff

 

The correct air pressure for your car tyres should be stated in your vehicle's handbook and are usually also found at the side of your car doors. If you cannot find the specification or in doubt, you can contact TyreQueen at 63777777 for assistance.

 

 

Sometimes it's in Japanese / Korean words though, might be time to use Google Translator but normally, there will be pictures (3 people or 5 people?)

Edited March 22, 2014 by Tyrequeen

[Tyrequeen]

Hi Guys, we have made a rather long FAQ about-Tyres here at TyreQueen-How-To-Choose-Tyres (main guide) and we have included 6 sections at MyCarForum : We hope that you like them and found them useful, these are written to the best of my knowledge and if there's any part that needs to be edited, I will truly appreciate if you could PM me and let me know :) - Eric C

Here are the 6 sections and the Tyre-Prices Guide :

1. Main Tyre-Selection Guide (with many more sections) #0
2. How to Choose The Right-Tyres Part #1
3. How to Choose Tyre-Tread Patterns #2
4. How to Know Tyres-Correct Air Pressure #3
5. Are you ready for Run-Flat-Tyres? #4
6. When To Rotate My-Tyres & Rotation Patterns #5
7. How to Save Money On Fuel &-Tyres #6
8. Tyre-Price Guide

(Compare to find out if you are paying too much or getting a good deal)

 

[Jtyres]

Good assembly of information by tyrequen

[Tyrequeen]

Good assembly of information by tyrequen

 

Thank you!

[Jtyres]

Hope to see more interesting articles from TyreQueen!

 

 

Thank you!

 

[Tyrequeen]

Hope to see more interesting articles from TyreQueen!

 

 

 

Thank you for the support!

[Ken-sanki]

thk for sharing

Edited January 31, 2016 by Ken-sanki

[ditodito]

Wah nice info, thanks! Very useful for a first time user like myself. 

[Ixat]

Jus to add to the summary. You can actually pump pressure proportionately lower if your new tire had a higher load index which i wouldnt recommend unless u know how to calculate.

 

for a even more in depth read on P metric or Euro metric inflation

http://marktg.toyotires.com/file/loadinflationtable.pdf

 

Came across this thread when trying to figure out why my used-new car feels so bouncy and was feeling every imperfection on the road. I had thought this was the behavior of a 245/40/18 tires which I am not familiar with or my new coilovers were not as good as they claimed ("Like stock feeling"). Furthermore it is common to hear people describe 18" low profile tires as being uncomfortable.

 

The manufacturer's recommended tire pressure at 245/40/18 is 230kpa/220kpa and it is on tire with load index of 93W. I realised my new tires are 97Y which required a lower pressure meet the required load the tires should carry.

 

I had lowered my tire pressure based on the Toyo tire load inflation table (link below) and eventually settled on 200kpa/190kpa and the bouncy feel is gone and car totally feels compliant. Tire wear is even across the tire after 10,000km and fuel consumption is similar to when I was pumping 230/220.

 

https://toyotires2-1524598101.netdna-ssl.com/assets/lib:toyo%20content/Application_of_Load_Inflation_Tables_20151020.pdf

 

Just sharing in case anyone was in a situation like mine.

Edited March 7, 2016 by Ixat

[coolbluepica]

Hi Tyre Queen,

 

I'm driving a Kia K3 and recommended tyre pressure is 32psi stated by car maker. I'm on 17/45/17 and feels that the tyres side wall are sagged while on 32psi. I've tried 35psi but ride feels very bumpy. Reduced to 34psi and seems just right. Do you know what's they best tyre pressure for comfort and FC?

 

And I'm thinking to upgrade to 18" which shop tells me need to be on 40 profile as 45 can't clear. Will 18" 40profile affects the comfort and FC and power of the car?

 

Thanks in advance for advise.

Hi Tyre Queen,

 

I'm driving a Kia K3 and recommended tyre pressure is 32psi stated by car maker. I'm on 17/45/17 and feels that the tyres side wall are sagged while on 32psi. I've tried 35psi but ride feels very bumpy. Reduced to 34psi and seems just right. Do you know what's they best tyre pressure for comfort and FC?

 

And I'm thinking to upgrade to 18" which shop tells me need to be on 40 profile as 45 can't clear. Will 18" 40profile affects the comfort and FC and power of the car?

 

Thanks in advance for advise.

Sorry typo my current tyre is 225/45/R17.

[Doppel]

Hi Tyre Queen,

 

I'm driving a Kia K3 and recommended tyre pressure is 32psi stated by car maker. I'm on 17/45/17 and feels that the tyres side wall are sagged while on 32psi. I've tried 35psi but ride feels very bumpy. Reduced to 34psi and seems just right. Do you know what's they best tyre pressure for comfort and FC?

 

And I'm thinking to upgrade to 18" which shop tells me need to be on 40 profile as 45 can't clear. Will 18" 40profile affects the comfort and FC and power of the car?

 

Thanks in advance for advise.

Sorry typo my current tyre is 225/45/R17.

Bro,

 

TyreQueen already closed shop Liao.

 

You can adjust the tire pressure beyond the recommended manufacturer's settings for your driving comfort.

 

40 profile cornering better, but FC and comfort would take a hit, power likely also take a hit (unless you go with forged lightweight rims); given your preference for comfort, recommend you stick with your 17".

[coolbluepica]

Bro,

 

TyreQueen already closed shop Liao.

 

You can adjust the tire pressure beyond the recommended manufacturer's settings for your driving comfort.

 

40 profile cornering better, but FC and comfort would take a hit, power likely also take a hit (unless you go with forged lightweight rims); given your preference for comfort, recommend you stick with your 17".

Thanks a lot bro. If I follow Kia's recommended 32psi what is the take? I'm afraid it's abit too low.

[Roberttan]

Hi Tyre Queen,

 

I'm driving a Kia K3 and recommended tyre pressure is 32psi stated by car maker. I'm on 17/45/17 and feels that the tyres side wall are sagged while on 32psi. I've tried 35psi but ride feels very bumpy. Reduced to 34psi and seems just right. Do you know what's they best tyre pressure for comfort and FC?

 

And I'm thinking to upgrade to 18" which shop tells me need to be on 40 profile as 45 can't clear. Will 18" 40profile affects the comfort and FC and power of the car?

 

Thanks in advance for advise.

Sorry typo my current tyre is 225/45/R17.

your 17inch size for K3 I thought is 215/45/17 ? why 225/45/17 ?

if your concern is FC why you changed to wider size 225 ?

upsize to 18 generally FC and comfort will be compromised (not 100%)

if you want better FC and comfort , do check your owners manual for option / driver door pillar

can downside to manufacturer acceptable tire size, sure improve