is 300h tyre preasure

[giantjack]

Hello all,

I'm a new IS 300h owner (2013) coming from a 02 IS 200.

My tyre preasure yellow warning light is showing on the dash.

I read online the recommended preasure and decided to try 35 PSI. Went to my local petrol station and set the air machine to 35. For some reason they wouldn't go up past 30-31 PSI.

Perhaps I'm showing my lack of car knowledge here. Is 35 PSI recommended for the IS300h?

PS: Absolutely love the 300h. Coming from an 02 IS 200 which lasted me 7 years it is a huge upgrade.

Thanks,
jack

[royoftherovers]

1 minute ago, giantjack said:

Hello all,

I'm a new IS 300h owner (2013) coming from a 02 IS 200.

My tyre preasure yellow warning light is showing on the dash.

I read online the recommended preasure and decided to try 35 PSI. Went to my local petrol station and set the air machine to 35. For some reason they wouldn't go up past 30-31 PSI.

Perhaps I'm showing my lack of car knowledge here. Is 35 PSI recommended for the IS300h?

PS: Absolutely love the 300h. Coming from an 02 IS 200 which lasted me 7 years it is a huge upgrade.

Thanks,
Jack

Follow what the Handbook says jack, nothing else.

[ColinBarber]

1 hour ago, giantjack said:

Is 35 PSI recommended for the IS300h?

36 PSI.

[200h]

i always kept my IS300h's tyre pressures at 36psi / 2.5bar

[giantjack]

Thanks everyone, I will try another machine at 36 PSI

[200h]

after your cars been serviced at lexus if you look at the tyre report

regarding tyre wear you can tell if the pressures are correct as you

will have even wear across the tyre OR

tyres under inflated- more tread around the centre

tyres over inflated - less tread around the centre

[paulrnx]

Gauges on airlines at garages are often inaccurate in my experience. By all means use their airlines but better to have a gauge of your own to accurately check the pressure after. If you do have to drive more than a few miles to the garage your tyres will also have started to heat up which will give an increased pressure reading. Especially if you have driven at high speed, eg along a dual carriageway. If you can’t avoid this then inflate to 1 psi more than the recommended pressures. If tyres are very hot then inflate to 2-3 psi over the recommended reading. Pressures should really be checked on cold tyres but in ambient temperatures of more than about 5-7 degrees C. This is because colder ambient temperatures will also lead to a lower pressure reading. In very cold temperatures I’d add 1 -2 psi to the recommended settings to compensate. Once satisfied that all pressures are correct then you’ll need to reset the tyre pressure monitoring system. This will correctly set the level that continuous tyre pressure measurements will be compared to.

The main reason that tyre pressure monitoring systems give a warning in winter is related to the above. Over time a tyre will suffer from a little pressure drop because they will lose a little air. This, together with colder winter temperatures where a tyre’s pressure will also drop is often enough to trigger a warning. Often you’ll find that driving the car until the tyres warm up will clear the warning (because pressure will increase as the tyre warms up) but this should be treated as a warning that the tyres are no longer set to their recommended pressure or at least the pressure that the TPMS is monitoring at and pressures should be checked and the TPMS reset.

Having TPMS fitted is not a reason to never check tyre pressures. TPMS will give a warning when the pressure in a tyre drops by a specific amount which is of the order of about 3-4 psi. What it won’t therefore do is warn that over time the pressure in a tyre has dropped by say 2 psi.

 I’m not trying to preach here. Tyres are the only things that keep a car on the road when cornering and I regularly check mine about every 500-1,000 miles to keep them at the optimum pressure. TPMS is a great system for warning when pressure in a tyre or number of tyres has dropped but it shouldn’t replace regular checks.

[Thackeray]

For the last few months I've been using an app called Tire Assistant which displays the readings transmitted by the TPMS sensors. I've found that the sensors are pretty accurate when checked against a reliable pressure gauge. Garage pump gauges are often inaccurate.

This is a link to a thread about Tire Assistant.

When the car is starting from cold the engine runs at a low power setting for about a minute and it doesn't generate any electricity that can be saved in the hybrid Battery during this low power state. I've read that some Prius drivers try to maximise their mpg by not driving the car until this low power state ends. This is interesting but probably not worth doing in financial terms. But if I'm not in a hurry I sometimes start the car and then check Tire Assistant while the engine warms up for a minute or so before setting off. I don't have to get out of the car to check the tyres and with little effort I have the reassurance before setting off that the tyres are ok.

[paulrnx]

I’ve often thought it pretty poor that the Lexus TPMS (or at least the systems fitted to the IS and NX) do not show individual tyre pressures.

[200h]

the RC and the GS both have individual tyre pressures

someone on here purchased a module to give you

this output on their cars screen but i cant for the life of me

remember the members name

[ColinBarber]

3 hours ago, paulrnx said:

I’ve often thought it pretty poor that the Lexus TPMS (or at least the systems fitted to the IS and NX) do not show individual tyre pressures.

The system receives individual pressures but it only uses a single receiver so cannot determine which reading relates to which corner of the vehicle. There are third party apps that can display this information which Thackeray has linked to.

For the vehicles that display the tyre pressures, a more expensive system is used with multiple receivers so the position of each tyre can be determined, and will correctly display each corner even if the wheels have been rotated around the vehicle to even out tyre wear.

[matt8]

4 hours ago, 200h said:

the RC and the GS both have individual tyre pressures

someone on here purchased a module to give you

this output on their cars screen but i cant for the life of me

remember the members name

@Andrew888