[msdivy]

Honda recommends 32 (Front) and 30 (Rear) for NHC GXi/EXi.
(in the pic it is mentioned as 29 for both, which is wrong).

[n_aditya]

Hi guys...

got myself new Michelin XM1 tires (4 nos) for my esteem in Nov'06.

All tires were filled with Nitrogen but pressure seems to be declining in front tires by 4 PSI while rear's lose 2 psi.... found this out and topped up to 28 psi on thursday last week.... 3 days later the same issue... had to fill up regular air just before my return to chennai...

the spare tube type seems to maintain constant pressure....

are my tires faulty or is it an issue with the valves?

'cos i heard nitrogen is not as volatile as regular air and when filled with Nitrogen the pressure remains almost unchanged for as much as 6 months...

P.S. the dealer said the valves were imported (it had Germany embossed on it... not that i trust the markings... i trust the dealer more cos he was ref. by a fellow BHP'ian)... so what do u guys suggest? I will be going on the weekend to sort this out.... any ideas where I can get reliable valves?

[iraghava]

It could either be valves which are not properly seated & hence leaking air slowly or it could be a puncture. I personally think it's a slow puncture since in tubeless the deflation usually is very slow, so get the tyres & the valves checked up properly. I don't think it's a big problem. How many tyres of yours is this happening in?

[rks]

Originally Posted by n_aditya

Hi guys...

got myself new Michelin XM1 tires (4 nos) for my esteem in Nov'06.

All tires were filled with Nitrogen but pressure seems to be declining in front tires by 4 PSI while rear's lose 2 psi.... found this out and topped up to 28 psi on thursday last week.... 3 days later the same issue... had to fill up regular air just before my return to chennai...

the spare tube type seems to maintain constant pressure....

are my tires faulty or is it an issue with the valves?

I think you should check your tyre pressures in cold condition (preferably first thing in the morning) before the car does any running. And use an accurate gauge -- do not trust bunks. Plus your car will have run some distance before reaching a bunk, which will cause errors due to heating up. I found similar variations due to a faulty pressure gauge and also due to measuring in bunks while the tyres where hot. I then did what I advocated above and the (tubeless) tyre pressures are rock-steady, even after 3-4 weeks. I note that you do not have any problems with your spare tyre, which of course, is always cold.

If you have a problem with leaky valves, you should be able to detect the leaks by using soap solution. If no leaks are detectable, the valves are probably OK. If you are using steel rims and if they are rusted/bent then there is a possibility of air leakage from the beading. You can also probably check this with soap solution if the leakage is not too slow. Then the only soution is to either change the rims or to remove the tyres and properly clean out the rust and straighten out any bends. If you are using alloys there should be no problems here.

[n_aditya]

Originally Posted by rks

I think you should check your tyre pressures in cold condition (preferably first thing in the morning) before the car does any running. And use an accurate gauge -- do not trust bunks. Plus your car will have run some distance before reaching a bunk, which will cause errors due to heating up. I found similar variations due to a faulty pressure gauge and also due to measuring in bunks while the tyres where hot. I then did what I advocated above and the (tubeless) tyre pressures are rock-steady, even after 3-4 weeks. I note that you do not have any problems with your spare tyre, which of course, is always cold.

Hi RKS,

I have filled all tires with nitrogen... so as per my understanding nitrogen is not susceptible to heat due to friction... please clarify.

[rks]

Originally Posted by n_aditya

Hi RKS,

I have filled all tires with nitrogen... so as per my understanding nitrogen is not susceptible to heat due to friction... please clarify.

Nitrogen probably has a higher specific heat than air (which I think is 70% nitrogen anyway). So it should be less susceptible to friction heat (less temperature fluctuation), but the effect will still be there. To be absolutely sure, I suggest you check your tyre pressures before the car has run.

In my case, the gauge I had (attached to my compressor) was faulty and the tyre pressures seemed to be varying wildly and I too almost panicked after changing to tubeless. The gauge would initially show 34 psi, then the indication (if the gauge is held for a while) would drop to 30 psi! When I checked with an accurate digital gauge the reading held at exactly 34 psi even after 3 weeks. But if you can get a good branded analog gauge that is also OK. The only problem with my gauge is that it lets out too much air when I check the pressure (0.5-1 psi loss) unless I can get it right quickly. This takes some practice.

[n_aditya]

Originally Posted by rks

But if you can get a good branded analog gauge that is also OK.

Thanks for the prompt reply RKS...

any idea where i can purchase a reliable and not very expensive guage? digital is preferred as long as its not way too expensive compared to the analog brother.

I have a few analog guages at home but they are as old as 10 years or more... so i dont know if they are dead accurate.

[rks]

@n_aditya: The digital gauge I have is by ROADGEAR (a UK company), and cost me quite a lot ($34, including $ 12 for shipping: approx. Rs. 1500/-) -- I ordered this gauge through the internet, and it is guaranteed for 5 years to give pressures accurate to +/- 0.5 psi. But the problem with this gauge is that it is optimized for bikes rather than cars (has a head that is at right angles to the gauge, so that it can reach through the spokes of the bike). So it is a bit difficult to take the reading without letting out too much air -- I did not realize this when I ordered the gauge, since the web site says that it can be used for cars too.

I am not sure on who currently supplies the best digiital/analog gauges for 4-wheelers. I am sure good stuff is available even locally and you will not have to dish out more than about Rs. 1000 for a good digital gauge. T-BHPians may be able to help you out here. You can try searching T-BHP postings -- I recollect seeing some info there.

Edit: If your analog gauges are more than 10 years old, they are probably not accurate -- rusting, dust, etc. will have taken its toll. So better to get new ones. Any good accessories shop will either have these or give you pointers on where to get them. The internet is also a good source of info.

If you are going to do a lot of highway driving, it is worth the money to get a good reliable gauge rather than rely on petrol bunks.

[rks]

The ROADGEAR digital gauge that I have is advertised in the following website (see "ROADGEAR Hi-Tec Digital Tire Gauge" or "Digital Tire Gauge Combo")

ROADGEAR | Products | Hi-Performance Motorcycle Gear

I got the Hi-Tec gauge, which "talks", i.e., you get to hear the reading, which is quite useful since you cannot always position the gauge to see the reading (especially in the dark).

I think ROADGEAR is a US company (I said UK in an earlier post).

Edit: There are many cheap "pencil-type" gauges available, but do not go in for these. They are terribly inaccurate and will not last long.

[men_in_jean]

Could anyone let me know what is the recommended air pressure for Lancer. I dont have the instruction manual of it. :(
Its a GLX-i model

[dhir_d]

i changed from my stock tyre 175/70 r13 to 185/70 r 13( tubeless)
the recommended tyre pressure on the stock tyre is 29 psi.
can i maintain the same pressure on the wider tyres..

[n_aditya]

Ok here's the update... picked up a nice tire guage from the dealer for Rs.450/- calibrated by bridgestone. (Has the bridgestone logo on it).

Checked pressure in all 5 tires and they are correct.

Damn petrol bunks have meters which are showing up all nonsense readings... wonder how frequently they are calibrated.

Dear RKS and IRaghava, thnx for all the help. Appreciate it a lot.

[autoenthusiast]

Hi n_aditya, is the gauge that you bought a digital one or an analogue one ?
Also could you tell me the model ? I too wanted to pick up one. Thanks.

[rks]

Originally Posted by dhir_d

i changed from my stock tyre 175/70 r13 to 185/70 r 13( tubeless)
the recommended tyre pressure on the stock tyre is 29 psi.
can i maintain the same pressure on the wider tyres..

You have gone for wider tyres of the same profile, presumably on the same (stock) wheels. This implies greater ride height and also greater sidewall deformation in cornering if you maintain the same stock pressures. Which means your ride comfort will increase, but the handling, especially cornering, may suffer despite the wider tyres. And your tyres may wear out asymmetrically, i.e., you may find greater wear at the edges as compared to the centre of the tyres if you maintain stock pressures, in which case your tyre life will be less than optimal.

So my guess is that you may be better off increasing the tyre pressures slightly, say, by 2 psi or more, for city use. For highways I would increase the pressures by 4-5 psi above the recommended pressures, since I do a lot of high-speed driving -- Bridgestone India recommends this and I have followed it with sucess in my Santro. But your car may react differently, and it is also a matter of your preferences.

Are you more particular about tyre life/handling than ride comfort? Do you do a lot of highway driving? Then do not hesitate to increase the tyre pressures. Otherwise increase in small increments and observe the ride comfort and your tyre wear -- if too much wear at the edges as compared to the centre of the tyres, then increase pressures further, etc.

Also make sure that you check your tyre pressures at least once a month and rotate tyres and check alignment/balancing at regular intervals, say every 5000 kms.

[n_aditya]

Originally Posted by autoenthusiast

Hi n_aditya, is the gauge that you bought a digital one or an analogue one ?
Also could you tell me the model ? I too wanted to pick up one. Thanks.

Well it is an analog type. Digital ones need recalibration every time battries are replaced (as per dealer) which is not worth it.

I shall post the pic of the guage in a day or two.