Jump to content
SAU Community

Possibly Serial Offender. Do I Keep Pumping Up My Tyres Too Much?

KrazyKong
 Share

Recommended Posts

KrazyKong Proficient

KrazyKong

Posted
Posted

I've always been a person who likes to have their tyres at the right PSI. However I never actually know what is the "right" PSI. Looking at the tyres gives you a MAX pressure number. This can vary from brand to brand and sizes. However most tyre places seem to under inflate the tyres in my view. Like putting in 26PSI when the max is 44PSI. I never go the max, but I would go maybe 38 to 40.

Am I really supposed to go on the PSI listed inside the door, even though I don't have the same rims or tyres that came with the car?

I occurred to me that maybe all these years I've been putting in too much air. Now that I got some new tyres, I think I need to fess up and say, I'm just confused now if I've ever been doing things right.

KrazyKong Proficient

KrazyKong

Posted
  • Author
Posted

One of my current Bridgestones is showing wear in the middle of the tyre so maybe I've had it pumped up too much. I normally go 41PSI as I found out you'd lose 1PSI when disconnecting the hose. So was running in effect 40PSI in the rears, but now think due to that wear patch maybe it was too high. I do like them firm though.

Duncan Grand Master

Duncan

Posted
Posted

Wear in the middle is a good indicator it's overinflated (and that will vary between tyres and sidewall heights)

Higher pressures can carry more load, will use less fuel and will handle better. Downside is they can be harsher (but frankly, if you are running 45 or lower profile tyres you've already decided to accept a harsher ride).

In my experience tyre shops and mechanics tend to go for a low pressure (30 or lower) and I honestly don't have any idea why

KrazyKong Proficient

KrazyKong

Posted
  • Author
Posted

Maybe it's speed. Quicker to fill it up to a lower pressure and thus time is money sort of thing? I have no idea why they under inflate either, but I've always known they have for some reason.

These tyres were used when I got them, so not too sure it was all me with the higher pressure, but I think for this next set I'll go lower. Instead of 40 maybe start at 36/37 and see how that goes.

I like them high, but don't want to wreck the tyres.

V28VX37 Veteran

V28VX37

Posted
Posted

Wear in the middle is a good indicator it's overinflated (and that will vary between tyres and sidewall heights)

Higher pressures can carry more load, will use less fuel and will handle better. Downside is they can be harsher (but frankly, if you are running 45 or lower profile tyres you've already decided to accept a harsher ride).

In my experience tyre shops and mechanics tend to go for a low pressure (30 or lower) and I honestly don't have any idea why

...to get more grip perhaps?

It's probably not as extreme as with semis but I'm pretty sure that the same street tyre will grip better at 32psi than 42psi...?

Duncan Grand Master

Duncan

Posted
Posted

interesting idea, I'd love to see a back to back test. yes lower pressure will give you more rubber on the road but I'm not certain that translates directly to extra grip because each contact patch will move more relative to the wheel

MBS206 Grand Master

MBS206

Posted
Posted

interesting idea, I'd love to see a back to back test. yes lower pressure will give you more rubber on the road but I'm not certain that translates directly to extra grip because each contact patch will move more relative to the wheel

Mythbusters proved it

http://actiontyres.worldsecuresystems.com/latest-news/effect-of-tyre-pressure-on-fuel-consumption

GTofuS-T Grand Master

GTofuS-T

Posted
Posted

FWIW I run 34 all around on 40 profile tyres, and at the moment have a really good alignment (for the first time in my life, i.e. no inner camber wear) and tyres are wearing evenly

No source, but I wasalways under the impression that higher pressure is better for fuel economy, lower pressure for grip, obviously to a point like so:

post-2-1196429733.jpg

niZmO_Man Grand Master

niZmO_Man

Posted
Posted

As usual, it's more complicated than it seems. 32psi is for putting around town with your family. I recommend 36psi for daily drivers, I run 38-40 depending on season/weather/tyre.

Cheap tyres generally need at least 40psi to get some grip out of it.

pol1on1 Mentor

pol1on1

Posted
Posted

My old mate a tyre guy and owner of his own tyre shop. I always bug him with questions which he doesn't like to give up his 40yrs experience......

Now he said not many people do it right dealership like soft gets a better sale softer ride.

Tyres say max.....

Door frame label says complete opposite.....

So on so on

Best is get a smooth flat ground dark as well. Now put some talcum powder on the ground in a line wide as ya finger but longer then ya tyre now push your car over the line keep rolling it 360 degrees so it makes a tyre print.

Now according to that print you would be able to tell if you need more or less you may need to do a few prints.

Remember front to rear will differ

Hope this help i might try make a video (if we have time ) with him helping me its a bit of an old art thats now days is forgotten.

Robocop2310 Experienced

Robocop2310

Posted
Posted

My old mate a tyre guy and owner of his own tyre shop. I always bug him with questions which he doesn't like to give up his 40yrs experience......

Now he said not many people do it right dealership like soft gets a better sale softer ride.

Tyres say max.....

Door frame label says complete opposite.....

So on so on

Best is get a smooth flat ground dark as well. Now put some talcum powder on the ground in a line wide as ya finger but longer then ya tyre now push your car over the line keep rolling it 360 degrees so it makes a tyre print.

Now according to that print you would be able to tell if you need more or less you may need to do a few prints.

Remember front to rear will differ

Hope this help i might try make a video (if we have time ) with him helping me its a bit of an old art thats now days is forgotten.

Sounds too damn complicated. How about you just tell us what you use on your tires? lol

pol1on1 Mentor

pol1on1

Posted
Posted (edited)

Unfortunately that would not work on your car unless you have a landcruiser with BFGs 265/65 r17 lol BTW dont own a skyline [emoji26] but i wish getting there.....

But yes all it takes is one person to do it then free 4 all

Example : R33 GT-R with Pirelli P Zero with this size ....______..... 36psi

Or with Proxes R888 size .._____.. 38psi

Its very rewarding at the end ;)

Edited by pol1on1

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • joshuaho96
      Front LSD Quaife , how streetable ?- QDF3L Owners

      By joshuaho96 · Posted

      Major thread necro but how bad of a job is it to DIY? Looking at it online it looks like if you reuse your ring and pinion as long as those are in good condition it should be fine to just pull the axles/front cover and replace the diff that way? Or should I be replacing everything and doing preload measurements/gear mesh testing like the factory service manual mentions for the rear diff?
    • Kinkstaah
      The FD RX7 is the best looking 90's JDM car

      By Kinkstaah · Posted

      in my list I had the R33 GTR as the best Skyline. Infact I had all GTR's (33>34=32), the NSX, the GTO, the 300ZX, the 180SX, the S15 better than the FD RX7. I had the MR2 and the A80 as 'just' better. I also think the DC5R Integra looks better but this is an 01 onwards car. I also think the FC>FD. It's almost like aesthetics are individual! The elements @GTSBoy likes about the FD and dislikes about the 180 are inverse in my eyes. I hate the rear end of the FD and it's weird tail lights that are bulbous and remind me of early hyundai excels. They are not striking, nor iconic, nor retro cool. The GTO has supercar proportions. I maintain these look much better in person (like the NSX) especially with nice wheels and suspension which is mandatory for all cars pretty much. Some (or all) of these you have to see in person to appreciate. You can't write a car off until you see one in the flesh IMO. Like most people we probably just like/dislike cars which represent certain eras of design or design styles in general. I also think the 60's Jag E type looks HORRIBLE, literally disgusting, and the 2000GT is nothing to write home about. FWIW I don't think the Dodge Viper Gen1's have aged very well either. You can probably see where I rate bubbly coupes like the FD. I know we're straying now but the C4 and C5 absolutely murder the Viper in the looks department as time goes on, for my eyes. Wouldn't surprise me if people who love the FD, also love the MX5, Dodge Viper, Jag E Type, etc etc.
    • GTSBoy
      The FD RX7 is the best looking 90's JDM car

      By GTSBoy · Posted

      I used to hate R31s, and any of the other Nissans that led up to it, and any of the Toyotas with similar styling, because of the boxiness. They were, and remain, childish, simplistic, and generally awful. I appreciate R31s a lot more now, but only the JDM 2 door. The ADM 4 door (and any other 4 door, even if they are unique compared to our local one) can eat a bowl of dicks. The Aussie R31 is also forever tarnished by their association with stereotypical bong clutching Aussie R31 owners of the 90s and early 2000s. I think the Nissans of the 70s (other than 120Y/180B/200B) are far superior looking to the 80s cars. The 240K era Skylines are boss. The same is broadly true of Toyotas. Hondas don't ever register in my thinking, from any era. Mitsus are all horrid shitboxen in any era, and so also don't register. Subarus are always awful, ditto. Daihatsus and Suzukis also don't generally register. They are all invisible. I think the SW20 MR2 looks fiddly. The 3000GT/GTO is like that but way worse. Too many silly plastic barnacles and fiddly gimmicks ruined what could have been a really nice base shape. Kinda-sorta looks like a big heavy ST165 Celica coupe (and I'm not sure if that's a good thing or a bad thing). I think the 180SX is dreadfully bland. It's not bad looking. But it has no excitement to it at all. It's just a liftback coupe thing with no interest in its lines, and bad graphical elements (ie wide expanses of taillight plastic on the rear garnish). The S13 Silvia is a little better - getting closer to R32 shapes. But still....bland. S14? Nope. Don't love it. S15...a little better. Probably a lot better, actually. Benefits from not being like a shrunk in the wash R34 (where the S13 was a shrunk in the wash R32 and the S14 looked like a Pulsar or something else from the stable on Nissan mid 90s horrors). The Z32 was hot as f**k when it came out but hasn't aged as well as the A80. Keep in mind that I think the R33 is the most disgusting looking thing - and out of all the previous cars mentioned is objectively closest to my precious R32. It's just....real bad, almost everywhere you look. And that is down to the majority of what was designed in the 90s being shit. All Nissans from that era look like shit. Most other brands ditto. In that context, the FD absolutely stands out as being by far the best looking car, for reasons already discussed. Going behind the aesthetics, the suspension alone makes it better than almost any other car.  
    • GTSBoy
      The FD RX7 is the best looking 90's JDM car

      By GTSBoy · Posted

      If they just called it the "Mazda Tiffany", it would have been spot on.
    • PLYNX
      The FD RX7 is the best looking 90's JDM car

      By PLYNX · Posted

      Yup but for me its the HR ! Cut my teeth on the old holden 6s in the day ! And here's me thinking in the day it was also the 300ZX and the Mitsubishi GT3000 ! All, as well had good lines, but always seemed to need finishing off, style wise.
×
×
  • Create New...