[Vid6639]

Originally Posted by V-16

I just swapped oe Goodyears 205/65/15R to 225/60/15
Michlien energys on my new inniva. the guy at the tyre shop
told me to maintain 33 in my tyres all round. I feel the tyres are overinflated
and the car seems bouncy. what would the correct psi be in
this case. also whn driving in hot concrete roads due to constant
friction, specially on cement roads, the psi tends to slightly icreasse
in the tyre. is it safe to derease the psi by say 2-4 pounds per tyre
keeping the hot increase in mind? Gurus?

Hey, V-16 if you feel 33psi is too much and the ride is on the bouncy side. First try reducing it 2psi. See if that helps. But the car should not become sluggish or steering too heavy. If it does then it was deflated a little too much.

31-32psi should be correct if 33psi is hard.

During highway driving yes due to the heat air inside expands causing an increase in pressure. This is ok. If you underinflate for highway you increase the rolling resistance and friction increases causing more heat which is not good. The increase due to the heat is nothing to worry about and there really is no need to compensate for that.

[mithun]

How can we arrive at the correct PSI after upsizing our stock OEM tyres ?

[v1p3r]

Well, for most Indian cars, 28-33 psi is enough. If you are using the same size rim, I would think you can persist with the same pressure. Also, use your gut feel. If it's too bouncy, depressurize, and vice-versa.

Ishan, is there a more technical way?

[crdi]

whatever the pressure choice, be sure that u get it inflated when the tyres are not hotter than normal outside air temperature (not ground temprature), driving a car even for a short distance heats up the tyres and you will never get a desired pressure or an even pressure in all the four tyres, best would be to check it at the nearest centre early in the morning or during servicing or alignment, provided the service and alignment intervals are not too long.

[shajufx]

I got a suggestion to hav 30 psi on all tires from the dealer for my bridgestone potenza 165/60 R13. But in effect he filled it with 30, 31, 32, 30 etc on 4 tires (1 different from other). It caused a bumpy ride and luckily my air pressure gauge helped me to check each one and correct it back to 29 psi on all tires. Now its comfortable and gives more road grip and steering ease. Its always better to try variations of 29, 30, 31 (same psi on all tires) at each filling and decide which suits your tire and vehicle. Even the suggested psi marked inside the vehicle need not be true when it comes to comfort and riding quality. So, personalise after checking different measurements.

[aah78]

whenever you guys measure tyre pressure please make sure that no two gauges are alike - there can be a 10% disparity in readings shown by different gauges.

the variations in readings change with ambient conditions.

eg. say at 22deg C, gauge 1 reads tyre pressure as 30psi but gauge 2 reads the same tyre pressure at 33psi.
if the temperature rises to 28deg C- gauge 1 might read 31psi but gauge 2 might read 35psi at the same time.
if the temperature drops to freezing conditions, the errors magnify and readings may vary over +-6psi.

i've checked this personally -compared readings using an analog gauge in a Pep Boys garage, a digital Michelin digital gauge, a Sears digital gauge, an Accutire digital gauge, and another local digital gauge (i forget the make).

there are a couple of calibrated gauges available - they're mainly analog and expensive compared to the ones widely available - you can check them up online via any search engine.

[RajaTaurus]

My experience is, in my Cedia, Bridgestone Potenza (stock tires), the dealer's serviceman kept 30 psi (per mark on the car), the ride was too bumpy and even car was rattling like hell over rough and bumpy roads (most of the time I drive alone in the car).
Then I cut back to 28 psi and the car ride totally changed. Though mileage will not change siginificantly, the ride is great with me and one passenger.
The recommended tire pressure is mainly for 5 people in the car with some cargo.
So, its better to decide the potimum pressure based on -
- How many people in the car.
- Ambient temperature (over inflating in a hot season is inviting danger of tire burst during harsh braking).
- Cargo and speed (for higher speed, you need to go up by 2-3 psi).

My experience Folks!!!

[PatienceWins]

The recommended tyre pressure for Getz is 30.
I have been filling 31 and I do not see any difference in ride. The handling seems to have improved.

[TDR]

Nice thread! Here in Europe "over inflating" tyres is actually recommended!

That is, if you're on fast "autobahn" roads, most of the time. Those roads
tend to be "podhole free". Since one is allowed to drive 120 to 130kmh,
or even more (in Germany) on these roads, slight "over inflating" really does
improve things. Improved fuel efficiency, less wear & tear (less heat), and more important, better performance due to lowered resistance.

My Maruti Zen tyres (Pirelli P3000) should be filled up to about 27~28 PSI
on the front and about 29 PSI on the rear. I'm running them with 30.5 PSI
on the front and 32PSI on the rear.

I must admit, though.... of the higway, in France (where roards can be pretty bad) I use the stock PSI.

TDR

[xingamazon]

I checked the forums for the right pressure to be pumped for my Zen Estilo (not the new one). I am slightly confused by different recommendation.

I am guessing putting 33 psi would be ideal, anybody thinks its not recommended please let me know.

I too have a similar experience, where i have run my 2009 mhawk 23000Kms+ at 40PSI(recommended is 32)without any uneven wear&tear.The down side i feel is the ride quality is stiff,Have not been able to notice any significant difference in FE.
I experienced major difference (-4KMPL) in FE of my NHC2004 when I floored the pedal.However, in mhawk there is hardly any!!
Even if I drive the best possible - let it roll in neutral, the maximum visible difference +/- 0.5KMPL!!
Regards