Correct Tyre Pressures

[Kaizer Sozay]

Hi, I have a Zen 2002 model which came with tyres 145/80 R 12 71 S, the recomended tyre pressure for these tyres was 24 psi. I have installed Michelin tubeless tyre 155/70 R13 75 H. now im not quite sure what pressure i should fill the tures up to. I currently fill it to 28 psi.. i do a lot of city driving. also if ones does drive on the expressway what should the pressure be. I read that the wrong tyre pressure can have a great affect on the FE.

[Shan2nu]

To begin with, stick with the 24psi recomended by the company.

If you notice any uneven wear or reduced FE, increase it to 26psi.

I upgraded from 175/65 R14 to 195/60 R14 on my Vtec and have been using 30psi (front) and 29psi (back) against 29psi (all round) recomended by the company. Haven't faced any problems so far.

Shan2nu

[Kaizer Sozay]

thanks but the ride does feel good at 28 psi, there is no uneven wear on the tyres. also i have moved 1 inch higher from an r 12 to r 13 in tyre size.

[The Wolf]

Originally Posted by Shan2nu

To begin with, stick with the 24psi recomended by the company. If you notice any uneven wear or reduced FE, increase it to 26psi. Shan2nu

Hey cmon Shan2nu, you cant be asking him to wait till he deforms his tyres, can you??

ajalphonso: Stick to 26psi till you get a confirmation.In the meanwhile confirm with the tyre guys or showroom guys. I suggested 26psi for one simple fact, wee bit over inflation is safer than wee bit under inflation...If your ride is too bumpy or rough with 26psi then reconsider and go back to 1st suggestion.

[karthik247]

Guys do all tyre of the same size have the same PSI or does it cary with the manufacturer too?

[Shan2nu]

Hey cmon Shan2nu, you cant be asking him to wait till he deforms his tyres, can you??

LOL, i didn't mean to ask him to wait until one side went bald. And 2ndly, most suspensions are setup to create a slight negative camber when the car is lowered to the ground.

A slight inner wear is natural.

Shan2nu

[Shan2nu]

Guys do all tyre of the same size have the same PSI or does it cary with the manufacturer too?

There's not fixed given pressure for any tyre.

The pressure of a tyre depends on the amount of load excerted by the vehicle, the speed at which the vehicle would be travelling, the weight distribution of the car and the owners priority towards comfort or performance.

The company reccomended pressure can be taken as a reference point but, you can increase or decrease the pressure according to your needs ......upto a point where it won't cause uneven wear or over strain the side walls.

Shan2nu

[5u3zEr0]

Even I had Michelin Certis tubeless tyres 165/65 R13 on traxx rims on my ex-zen and I used to keep the tyre pressure at 28psi for city driving and 30 psi for the highways. With these tyre pessures I used to get 12kmpl in the city and 15/16 kmpl on the highways with the a/c on all the time.

You could experiment with 26 and 28 psi and find out which one you are comfortable with.

[rzoster]

I do have a doubt here. Won't the tyre pressure increase as the tyre heats up? I'm asking this because, normally, when you go down to the petrol pump for an air check, your car would have travelled for some time, and the tyre would have heated up. Hence if you fill it at 24 when its hot, it might go down to 23/22 when it gets cold. This is just a guess. I'm not really sure if the tyre temperature makes a considerable difference anyway!

[revtech]

hey rzoster
tyre pressure should always be checked on cold tyres.as far as possible you should go to a pump which is as close to you as possible in order to ensure that the tyres dont become hot before being checked.


rev

[Kaizer Sozay]

thanks for the posts, but i found that the santro has the same spec tyres, and the sticker says that they have to fill 30 PSI. I havent tried that till date. Any downside it i increase it to 30, how will i know if there is a problem immediately

[revtech]

in my zen the oe rim size is 145/80 R 13. i think the old carb zens had 13 inch rims.anyway the recommended pressure is 30 psi..yeah im talking about the zen.is it a misprint or what.i normally fill 28 psi.


Rev

[imjimmy]

I had changed my tyres on my old zen to 145/70 R 13 recently. The stock zen comes with 145/80 r 12 i think.

Anyway i am using 28 Psi for 145/70 R 13 tyres.
I was using 30 psi earlier but the car was too bumpy and felt very light.

however i must add the pickup and the FE with 30 Psi was amazing.

What's the stock tyre pressure for the Zen?

[revtech]

Fe will definitly be more if the tyre pressure is at 30 psi if driven the same way.but i really didnt feel a difference in acceleration.even if ther was a difference im sure its negligible.but then again if acceleration increase one tends to push the car more which obiously results in a drop in FE.

28 psi definitly make the ride much better and more comfortable.with the amount of pot holes and un levelled roads driving at 30 psi is really unthinkable.


Rev

[somebodystopme]

I've got an esteem with company fitted tyre and i want to know wht should b da right amount of air one should fill in it, right now the oetrolpump where i go filld upto 30