Obtaining tire pressure information
 

Goddamn it, why is it *so* difficult to get tyre pressure informations? I need to choose a tire that can take 51 PSI - for FE reasons, but also because my car manual also specifies a 49 PSI figure for my car. But no-one is willing to give me pressure figures - I just got off the phone from a tyre shop and they refused to quote figures, just palming me off with "40 PSI" and "You shouldn't be going over this anyway" despite me telling them that's exactly what the car manual says. Why is no-one telling me this information - it's just wasting my time and it has taken me several weeks to try and choose a damn tire, and I'm nowhere near my final decision due to the lack of information.

Sorry, I just needed to let off steam.

From my experience... just buy a tire you like. Pump it up to whatever you like and be happy. :) I run my winter tires on the Matrix (sidewall max of 35 psi) at 50 psi and have run them for two years with zero problems. I've run my 44 psi max sidewall tires on the Paseo for two years at 60 psi with zero problems too. I know people running even higher pressures with no problems. I recommend finding a good low rolling resistance tire, and pumping it up to whatever you want. I doubt you'll have problems. IMO, the sidewall rating doesn't mean a ton.

Then why do they print the figures there? They wouldn't do that if it was a complete waste of time, wouldn't they? I'm just being curious.

On my really cheap low rated tires it seems that I get sidewall rot quicker when I run a lot above the rating, not sure you can really pin it down to any one thing, every tire is different.

Also if I remember some tires don't handle as well at their rated "speed rating" if the pressure is above their sidewall rating, since you probably don't drive 120mph it probably doesn't matter on that regard either.

Otherwise I'm not sure, many of the tires I run above the rating last longer, but some others wear unevenly and end up making my car vibrate.

Again this is from 15yrs of driving I can't really pinpoint if any of the above has to do with higher than normal pressure or not.

Good Luck

Goodyear & Michelin (I assume other mfgs. as well)websites list "Max load @ PSI" for their tires. I don't know if it is "max pressure" or not.

Don

I know from personal experience that the Sumitomo brand can run 51psi max pressures.

Hi Eddles. That has to be the worlds first car manual that specified such a pressure! Is that because it's the eco model?

ollie

Correct. The non ECO4 model with the exact same tire size quotes a figure of between 28-35 PSI.

Eddles,

Read this first:

Barry's Tire Tech

What you should get out of this is that what is printed on the sidewall is relatively arbitrary - which is why the tire shop wasn't particularly interested in answering your question. They saw it as something outside their need to understand - and in a lot of respects that is true.

But allow me correct a couple of misconceptions:

Yes, they would, if it were a government regulation - which it is!

The way the regulation is worded is that the max load and the max pressure have to be listed. For some reason - and I think it is historic in nature - some folks think these 2 things are related - and most of the time they are not.

Hmm. Interesting information. The guy said massively increasing the pressure above the placard doesn't make much difference - just a couple PSI over should be fine, so I might go for the Firestone F580's which is rated at 44PSI - I'm sure it can handle a few extra PSI.

Thanks very much for your time!