Where can I have my car weighed ?

[ER-3682]

On 7/9/2024 at 8:25 AM, Kklee said:

IMHO.
Which is why I am investigating if based on my usage the pressure for the front and back will need to differ if based on load.
My previous Toyota sedan recommendation was 220 / 210 where as the present hybrid compact SUV was 230 / 230.
With only the driver, I noticed that if I pump +10 kPA,  after driving over a puddle of water to determine the contact with the road,
the front has more contact vs the back which "shows" over inflated. 

Thus to understand this, I need to look at the weight for the front and back.   If the pressure and load index are the same,  the front/back
weight will determine the contact patch - grip.      Also, the tyres may last longer and probably the other by-product is FC. 

 

This is the Label on my Camry,i pumped 38 PSI on all 4 Tyres...but my Tyre's Size is 245/40-19.

Edited July 9 by ER-3682

[inlinesix]

On 7/9/2024 at 8:39 AM, ER-3682 said:

This is the Label on my Camry,i pumped 38 PSI on all 4 Tyres...but my Tyre's Size is 245/40-19.

Likely due to hybrid where front and rear weight is almost the same 

[ER-3682]

On 7/9/2024 at 8:44 AM, inlinesix said:

Likely due to hybrid where front and rear weight is almost the same 

Toyota never have 50-50 Weight Distribution...if BMW,Yes..my F22..but Tyre Label require Fronts to have lower pressure than Rears.

[inlinesix]

On 7/9/2024 at 8:47 AM, ER-3682 said:

Toyota never have 50-50 Weight Distribution...if BMW,Yes..my F22..but Tyre Label require Fronts to have lower pressure than Rears.

Your F22 tyre staggered.

Since it is RWD, rear usually higher pressure.

Non-hybrid Jap FWD should be higher front.

[Kklee]

On 7/9/2024 at 8:39 AM, ER-3682 said:

This is the Label on my Camry,i pumped 38 PSI on all 4 Tyres...but my Tyre's Size is 245/40-19.

IMHO.
What is your load index for the changed tyre and is it XL ?

[boonhat_91]

On 7/9/2024 at 8:39 AM, ER-3682 said:

This is the Label on my Camry,i pumped 38 PSI on all 4 Tyres...but my Tyre's Size is 245/40-19.

How did you arrive at 38 PSI? Since you upsized both the rim diameter and tyre width and lower profile.

[ER-3682]

On 7/9/2024 at 9:33 AM, Kklee said:

IMHO.
What is your load index for the changed tyre and is it XL ?

I don't think so..it is Michelin PS4.

[ER-3682]

On 7/9/2024 at 9:46 AM, boonhat_91 said:

How did you arrive at 38 PSI? Since you upsized both the rim diameter and tyre width and lower profile.

Just feel nice Handling & Economy.

[inlinesix]

Based on PS4 load index, it should be 31.  38 is really overinflate

[Kklee]

On 7/9/2024 at 10:19 AM, ER-3682 said:

I don't think so..it is Michelin PS4.

IMHO.
Based on a load index table for standard tyres,  load index 94 at 35 PSI supports 1433 lb or 651.36kg
The corresponding pressure for load index of 98 for 1433 lb is 30 PSI. 
Driving over a puddle of water and look at the tyres will give a good indication of the inflation. 
 

[Toeknee_33]

On 7/10/2024 at 7:58 AM, Kklee said:

IMHO.
Based on a load index table for standard tyres,  load index 94 at 35 PSI supports 1433 lb or 651.36kg
The corresponding pressure for load index of 98 for 1433 lb is 30 PSI. 
Driving over a puddle of water and look at the tyres will give a good indication of the inflation. 
 

IMHO, why do we need to try to outsmart the car manufacturer who has tonnes of resources and research done and has recommended to you to the tyre pressures, and sometimes even the make/model of the tyre?

A moving car has plenty of other dynamic forces acting on it that will affect the load of each wheel. Be it road irregularities, suspension geometries, aerodynamic forces, acceleration/deceleration, braking forces and countless others. Even the temperature of the tyre affects its inflation. Would you be able to predict the forces involved in all these different circumstances?

Rolling over a puddle is nonsensical, IMHO.

Edited July 10 by Toeknee_33

[Kklee]

On 7/10/2024 at 11:10 AM, Toeknee_33 said:

IMHO, why do we need to try to outsmart the car manufacturer who has tonnes of resources and research done and has recommended to you to the tyre pressures, and sometimes even the make/model of the tyre?

A moving car has plenty of other dynamic forces acting on it that will affect the load of each wheel. Be it road irregularities, suspension geometries, aerodynamic forces, acceleration/deceleration, braking forces and countless others. Even the temperature of the tyre affects its inflation. Would you be able to predict the forces involved in all these different circumstances?

Rolling over a puddle is nonsensical, IMHO.

IMHO.
This is for the drivers who differ from what the car manufacturer specified.  
There are quite a few drivers out there who don't know or don't ollow what the car manufacturer specified. 
They only see until Width, Aspect Ratio and Rim Diameter.
Often enough, most will be out of what was specified by the car manufacturer. 

I specifically use tyre temperature as my baseline to determine my tyre pressure.
My pressure can be different on rainy or summer "season".
I can even tell you which specific tyre for my vehicle will have a different temperature rise or
why I have to accept a compromise in my tyre pressure at different time of the day. 
The forces you mentioned above,  AFAIK,  race cars use temperature method taking into consideration all the forces.
In my experimental stage, I use a similar approach to determine my tyre pressure in relation with temperature. 

Rolling over a puddle is the easier way to see over inflation.  Like I mentioned above,  can use the racing car method. 
 

[Kklee]

On 7/25/2024 at 9:29 PM, richard223 said:

Interesting approach to tyre pressure based on temperature! Have you noticed any significant differences in handling or fuel efficiency since adopting this method?

 

IMHO.
In my experimentation so far, some interesting take away
-  more responsive to steering inputs 
- almost none tyre squeaking doing turns in MSCP after cold start
- higher speed doing roundabout turn than sedans and hatchbacks.  

Pre-analysis of FC seems to do about 0.5km/L better?