Tyres pressure for 225/45/R17

[Ct3833]

On 3/10/2023 at 11:32 AM, Senny said:

Hi sry bros, had to dig up this post again for the same tyre profile i had 225/45/r17 running on Michelin Sport 5 on lancer cs3

very bumpy/boaty ride even after changing shock absorbers

 

currently running on PSI 26 which is comfortable but not recommended by workshop

Seek any advice! 

Lower pressure would mean higher fuel consumption and faster tyre wear, plus more rolling and understeer effect. 

You are comparing with what tyre and rim size before? Larger wheel size at lower profile would give you harder ride but should not feel significantly difference,  did you do anything differently other than rims and tyres ? Otherwise, just stick to what you have.

[Hamburger]

26psi. Hot or cold tyre??

Most probably is warm and its not too high when cooled down. I often pump 26psi when warm.

[Watwheels]

Aiya, just have an air pump ready and do trial and error on the air pressure. Not difficult. 

[Senny]

On 3/10/2023 at 2:32 PM, Hamburger said:

26psi. Hot or cold tyre??

Most probably is warm and its not too high when cooled down. I often pump 26psi when warm.

when its warm, so you pump lower than 26psi as well for low profile tyres to get a better comfort but higher FC?

[Watwheels]

I dunno. To me low profile tyres have more cons than pros. Imo it is a waste of good money.

[Hamburger]

On 3/10/2023 at 6:24 PM, Senny said:

when its warm, so you pump lower than 26psi as well for low profile tyres to get a better comfort but higher FC?

Wrong input/unit. My bad.

I pumped 260kpa when warm so when it cools down it will be in the range of 230 to 240kpa.

When I go for highway driving over long distances, I pump 290kpa to help tyre sustain high heat and pressure.

FC has no bearing on me.

Edited March 10, 2023 by Hamburger

[Atonchia]

On 3/10/2023 at 11:32 AM, Senny said:

Hi sry bros, had to dig up this post again for the same tyre profile i had 225/45/r17 running on Michelin Sport 5 on lancer cs3

very bumpy/boaty ride even after changing shock absorbers

 

currently running on PSI 26 which is comfortable but not recommended by workshop

Seek any advice! 

Michelin is more popular for comfort than performance.

26 psi seemed on the low side. If too low, will increase more flex on the side walls which give you the floaty feel. 

Just follow the pressure guide on your door frame. 

My car recommended different pressure for front and rear tyres.  But I just lazy to change the setting when pumping. I just use the average of both. And 4 tyres running same PSI. 

[Jamesc]

26 psi is only 180 kpa.

Way too low!

Should be 220 - 250 kpa

I had to Google psi to kpa then shock to see less than 200 kpa.

[mersaylee]

On 3/11/2023 at 6:27 PM, Jamesc said:

26 psi is only 180 kpa.

Way too low!

Should be 220 - 250 kpa

I had to Google psi to kpa then shock to see less than 200 kpa.

I tink he meant to type 260 kpa lah...that's why a bit harsh on the ride...i used to pump 260-270...wife kpkb until I now quiet her down by going 240 niah 😅

[inlinesix]

On 3/11/2023 at 6:53 PM, mersaylee said:

I tink he meant to type 260 kpa lah...that's why a bit harsh on the ride...i used to pump 260-270...wife kpkb until I now quiet her down by going 240 niah 😅

What's factory's recommendation and load index?

[mersaylee]

On 3/11/2023 at 7:12 PM, inlinesix said:

What's factory's recommendation and load index?

Load and speed dependent 240-260 

[inlinesix]

On 3/11/2023 at 8:55 PM, mersaylee said:

Load and speed dependent 240-260 

It is likely current tyre load index is higher than factory spec.

For e.g., factory spec load index is 93 (it is in the sticker on A pillar). Your current tyre could be 95.

Edited March 11, 2023 by inlinesix

[ER-3682]

I followed the Sticker on the Car,i put 36psi front & 38psi rear,but have changed to non RFT.

[Senny]

@Hamburger  i see! 

 

i am testing out 230kPa now

seems much comfort than 180kPa, i think the lower the kPa it will be more comfort, turns out higher kPa 230 works normal and better for me

[Hamburger]

On 3/12/2023 at 11:42 PM, Senny said:

@Hamburger  i see! 

 

i am testing out 230kPa now

seems much comfort than 180kPa, i think the lower the kPa it will be more comfort, turns out higher kPa 230 works normal and better for me

I never seen recommended tyre pressure at 180kpa, normally it's 220 and above.

If your tyre is not cold, pump it to at least  250kpa so when it's cooled down, it should be in the range of 220-235kpa.

[inlinesix]

On 3/12/2023 at 11:42 PM, Senny said:

@Hamburger  i see! 

 

i am testing out 230kPa now

seems much comfort than 180kPa, i think the lower the kPa it will be more comfort, turns out higher kPa 230 works normal and better for me

For Mini, if pump 260kpa (minimum pressure), confirm bouncy for PS4.

Nowadays, I pump to 290kpa.  No bouncy.

 

[Roberttan]

On 3/10/2023 at 11:32 AM, Senny said:

Hi sry bros, had to dig up this post again for the same tyre profile i had 225/45/r17 running on Michelin Sport 5 on lancer cs3

very bumpy/boaty ride even after changing shock absorbers

 

currently running on PSI 26 which is comfortable but not recommended by workshop

Seek any advice! 

good afternoon

if your original tire size is  185/65/14  or 195/55/15 from factory and now running on 225/45/17 is upsize 3 time and 225/45/17 is way too big and too tall for your car,

is very normal to feel bumpy and boaty , is not correct to reduce the tire pressure as your workshop said , running on under inflater tire can lead to higher fuel burning and excessive tire wear and poor road handling.

always follow what car maker or tire maker recommendation you wont go wrong.