hey all
anyone run lower pressure than 38psi on OEM tyres ? Car seems very stiff and rattly on crapy bumpy roads !
hey all
anyone run lower pressure than 38psi on OEM tyres ? Car seems very stiff and rattly on crapy bumpy roads !
Last edited by kovmps6; 05-08-2009 at 10:12 AM.
even on my sp23, i run 38...
I run with 38psi and found the ride normal with OEM tyres, now I don't worry too much about ride on bad roads, I just accept that I'm going to be in for a rough time (lowered on Cusco Coilies, better looks + flat handling = hard ride on bad roads, smooth roads are great!)
I run 38PSI with Nitro in my tyres, and at the end of the day if you want performance tyres and low profiles there is no fix I'm sorry unless someone thinks different.
On my OEM Rims and Tyres I used to run 40psi, preferred the more responsive feel through the steering, sure it was a bit more bumpy, but I could live with that. Now with my 225\40 falkens on my ROH Mantis rims, I've got it at 42 psi. The tyre has a softer side wall to the potenzas and is a quieter tyre, so 42 psi, is still pretty comfy.
225/45 R18 on Stock rims.
Commuting: 38-40PSI
Mountain: 33-35PSI
Track: 30-33PSI
That also depends on which tyre I'm running.
I usually run 38 all round too on my OEM rims and tyres
You need you tyres rotated! hahaha
I'm the opposite to Dotty.
I run 36 up front and 40 in the rear, soft front, firm rear, better traction, less handling, which what I think we all need.
Interesting running it that way around... have you compared soft and hard fronts to the opposite rears?
I'm not like that Dotty
Soft front lets the sidewall flex more, making the tyre slightly wider.
Firm rear stops the back squatting.
Man I always pumped my tyres up to 38 - 40PSI to prevent the tyres from rolling under on the track. I used to run 36PSI on the road and now run 38PSI after doing some track times but I do have NITRO in my tyres which keeps my temperature consistent, no expansion when the going gets hot in turn gives better tyre wear. I have been on the track twice and driven the car pretty hard but no big burnouts and I'm on track to get 35 to 37,000k's out my tyres with even wear right across the tyre. I'm still on stock tyres...... Which to answer your question above 30-33PSI for track surprises me..... Last thing you want is tyre rolling under when you are hitting the dirt/grass/gravel on the track.....
Those are all cold pressures, but as I said it depends on which tyre you're running. Sidewall flex amongst many other characteristics differ greatly between the various tyres. The only tyres I've ever had collapse were the RE050 and V103, which admittedly I was pushing too hard on a sharp downhill, cambered hairpin.... Some tyres perform well at lower pressures and some under higher pressures. It's very tyre specific and the only way to find out is to gain experience with each tyre. It's never a simple matter of which pressures do you run. There's a lot more to it than that.
If you over-inflate your tyres on the track (or the road) you'll very quickly wear the middle and the shoulders off them.
Last edited by Jeev; 04-08-2009 at 09:51 PM.
I am Bridgestone thru and thru, I have run yoko's and they were ok, since I started using Nitro in my tyres I have run 235/40/18 , 235/50/16 ? 215/40/17 , 215/45/17 from statesmans to HSV GTO's to Astra and now the MPS3 and I have towed tandem trailers full of racing Go-karts and spares and tools , hard driving and some track times and have run them all at 38PSI and the tyres are so evenly worn across the whole tyre, that Bob Jane's always comment on how my tyres always wear perfectly doesn't matter how hard I have driven it, I get some scaffing on the left hand front corner because of how the track is set at Qld Raceway. I understand what you are saying, I have been to so many defensive courses sponsored by my suppliers that the first thing they have all of us do is pump our tyres up and because I use Nitro they ask what pressure are in my tyres, I always get them checked the day before I go out to the track to make sure that I have 38 in each tyre.... No one is right or wrong justing putting forward my imput......
I didn't take it that way either. Even running Nitrogen, track temperatures can see tyre pressures increase 3-4 PSI or more depending on your initial temperature, tyre size, rubber compound and god knows how many other things that relate to the surface and conditions on the day. I've always been a little sceptical of the use of Nitrogen itself in conventional vehicle tyres given that air is 78% Nitrogen. Of course that 22% difference seems large, but the fact that gas leaches through the rubber structure of tyres themselves means that eventually that margin blurs. You may find it interesting to monitor your tyre pressures on the morning of, as well as throughout the day and not the night before if you're headed to the track. My driving style and tyre choice obviously differ from your own and as such I can run my 30-33-35 PSI and still get even wear, but I trade higher levels of grip for a slight loss of feedback by doing so.
Bridgestone makes a good product, but I draw the line at saying that the performance quality of what they provide is actually worth the price tag they put on it. This is the same for Yokohama and a couple of other manufacturers too. Given the tyres I've run on my MPS commuting, hard driving, towing trailers or not I can say that there are tyres on offer which will do the same or better than the above for a fraction of the price, with less noise, more comfort, better performance or longer life depending on the sort of driver you are and what you're after.
At the end of the day I still consider tyres to be a bit of a black art and just about any question concerning them is more or less a matter of "How long is a piece of string?". There are too many variables to give one answer.
i agree with jeevs how long is a piece of string to many variables i run 40psi rear 38psi front with nitro and get even tyre wear no matter how hard the mps is driven
The original poster stated OEM tyre pressures on the title, but, OEM rims in the thread. I think this defined how long the string was and what the string was made from.
But, I have a 3, the OT has a 6. Not always informative between 2 different cars anyway.
Last edited by 2XS; 05-08-2009 at 07:15 AM.
Thanks Jeev taking it all in, I'm so Bridgestone that after driving other cars with different tyres I haven't ventured out my circle, I have being driving for 28 years now and tyres have probably improved, I should look outside the square. I do have one question which was brought up at a mazda performance day and that was with people who had changed their tyres to different makes "Quote" this will affect all your electronics with all the safety features built in for cornering braking etc etc. Then I asked well what happens when they stop making the tyres that come with the car, there was a long pause with no real answer?????? Great reading I'm so used to getting advise and paying for it......
When looking at things like the DSC, TSC and ABS/EBD you have to take into account that the control systems are configured and optimised for those OEM tyres, which is to say a tyre that has x traction, y stiffness and z so on. To some degree they're correct in saying it will effect your electronics, but it won't make them stop working altogether or necessarily make them work worse. It simply effects at which point the electronics begin to work and how quickly they respond by this stage. I wouldn't worry too much about it, considering anyone looking at hitting the track or driving the car on it's limit would have the tech toys turned off anyway.
Good point. I'll stop spamming now