Fustrated with tyre pressure...

**aaronng** · 18-09-2008 12:31 AM

Originally Posted by CB7_OWNER

When you mention the automated pressure inflators at servos... i noticed...

Say i inflate the tyre to 36 psi....then i remove the hose,...and to double check, i put the hose on again on the same tyre.. and it starts pumping up from 34psi...soo its lyk soo wtf???

But back to topic, i don't think 3-4psi is goner make much of a difference in tyre noise??

On my car, there is a very big difference between 34psi and 38psi. 38 is bad enough for me to stop at the side of the road after inflating, just to deflate it back to 36psi!

**Mugen Civic** · 18-09-2008 12:32 AM

humming may come from the tyre uneven wear, not so much like camber wear but that the tyre may not be exactly circle. May not be noticable to the naked eye.

happened to me sometimes due to bad shocks.

Just a thought

**vinnY** · 18-09-2008 12:38 AM

out of curiosity what tyres are on there at the moment?

**huhjared** · 18-09-2008 12:55 AM

supposed to be quiet tyres... goodyear excellence... erm... regarding them being not round... they are brand new... 4 weeks old... yeah...jest came back from the servo with the manual pump things... did 34 psi on the front and 33psi on the back... hopefully would be as quiet as when i got them from the dealer (26PSI) but i doubt so...

**JohnL** · 18-09-2008 10:53 AM

I think it might have been 'Choice' magazine that some years ago did a survey of servo pressure guages, and found that very few were reasonably accurate, and some were very very inaccurate. Don't trust them. The 'pens' are junk. Not all the dial types are good, but it's a better chance than the other types (decent ones probably start around the $50 mark?, but some cheaper ones are probably OK, though the cheaper it is the less likely it is that each individual guage is checked at the factory...).

When I first bought my dial guage I took it to a tyre shop and checked it against a rather flash / expensive looking guage they kept to calibrate their air line guages, and it was within 0.5 psi of that one, which is pretty good.

Even good quality dial types tend to be rather fragile, i.e. the calibration is easily thrown off if you say drop them onto a hard surface. This is why you'll see the more expensive ones fitted with a protective rubber ring around the guage body. I dropped my dial guage and wrecked it, so as an emergency measure I bought a $20 digital guage from BigW, which seems to work acceptably and does at least give consistent readings (though I haven't checked it's accuracy against a known good guage).

If you get a good guage, it's a good idea to get a sturdy container to store it in. I used a tupperware style box and put some foam into the box into which I cut pockets for the guage to sit.

**JohnL** · 18-09-2008 11:06 AM

Originally Posted by Mugen Civic

humming may come from the tyre uneven wear, not so much like camber wear but that the tyre may not be exactly circle. May not be noticable to the naked eye.

happened to me sometimes due to bad shocks.

Just a thought

A bit sceptical on that one.

My understanding is that tyre noise comes from the tread pattern itself (some patterns being inherantly noisier than others, tending to be noisier with the patterns that give better steering response etc as used on 'high performance' tyres...), but can be excacerbated by stiffer sidewalls or higher inflation psi.

I suspect (meaning I'm only speculating) that this might be because more noise is transferred through the stiffer sidewall (being actually stiffer or effectively stiffer due higher psi) into the suspension and steering linkages, and from there into the chassis...?