Tyre Pressures RAV4 PHEV TPMS

[Paul1905]

Hi

can I just check my thinking - I’ve been getting the warnings this week and I’m not really sure what my system pressure is set to.

Should I put all my tyres to 33 as per the door plate - reset the TPMS system using the car menu and then inflate all to 35/36 PSI, would that out my system into a decent setting?

thanks

[Hadrian1]

It's quite common to start getting pressure warnings this time of the year.

I didn't bother playing around with the TPMS settings. I just inflated the tyres to about 35psi and the warnings stopped.

Don't forget the spare. If it's a space saver it needs to be about 60psi.

[ernieb]

Colder days and the tyre pressure will drop. I have mine set to 33psi, CC2’s, on my ‘21 PHEV. 

[philip42h]

9 hours ago, Paul1905 said:

Hi

can I just check my thinking - I’ve been getting the warnings this week and I’m not really sure what my system pressure is set to.

Should I put all my tyres to 33 as per the door plate - reset the TPMS system using the car menu and then inflate all to 35/36 PSI, would that out my system into a decent setting?

thanks

Yes -ish. Set the tyres to the correct pressure and then reset the TPMS system.

I wouldn't then over-inflate the tyres - it isn't necessary.

The 'problem' seems to arise from the tyres being overinflated for delivery and not then set correctly at PDI.

[Paul1905]

53 minutes ago, philip42h said:

Yes -ish. Set the tyres to the correct pressure and then reset the TPMS system.

I wouldn't then over-inflate the tyres - it isn't necessary.

The 'problem' seems to arise from the tyres being overinflated for delivery and not then set correctly at PDI.

Thanks

i can work out the tolerance on them hence the ‘extra inflation’. If I set at 33, I’ll keep getting the notifications every time it dips with the cold was my thought process.

[philip42h]

35 minutes ago, Paul1905 said:

Thanks

i can work out the tolerance on them hence the ‘extra inflation’. If I set at 33, I’ll keep getting the notifications every time it dips with the cold was my thought process.

Yes, no ... they'll warn if the tyre pressure drops around 10% below the set pressure. So, if you set at 33 psi, they warn at around 28-29 psi - which is exactly what you want.

If they are warning at say 32 psi, that will be because the set pressure was incorrectly set at around 37 psi in the first place. All you have to do is set them correctly ... 😉

On my RAV4 I had to correct the set pressure in 2020 - 'cos it was set incorrectly. And I never had to mess with it again over the next four years summer or winter - tyres really don't gain or lose that much pressure ...

[Cyker]

I find I generally have a 4-6psi variance from the seasonal change in temps if I don't touch them.

[Nick72]

PV = nRT (ideal gas equation)

So P (pressure) is directly proportional to T in Kelvin.

High summer (not that we had any of it in the North) at say 27C or 300K versus 0C or 273K in winter would represent a pressure drop from summer to winter of around 9% (from (300-273) / 300).

So if 33psi in summer it will drop to 30psi in winter. For this example at least. 

I just aim for 33psi at 20C. And leave it, unless it needs topping up. Noting that a slight pressure drop in winter is beneficial for me as it means more tyre surface on the road and therefore better winter environment grip.

 

 

[TonyHSD]

Tyres loose pressure over time due to the temperature amplitude day/night. 
Less you drive the car more pressure drop will occur. 
Best practice is to keep tyres slightly over inflated to compensate any pressure drops.
If you drive a lot,  a routine pressure checks on cold is vital to maintain tyre longevity. Once every two weeks is a good starting point and use those monitoring systems on board as pressure warning in an emergency only not as guide about exact pressures in each tyre. 👌

[Paul1905]

Just wanted to say thank you for all contributions on this thread. Really helpful.