OK so I've been getting conflicting info about what tire pressure I should have for my tires the sticker on my car says somethign like 32 at the front and 28 at the back, while SoG recommended me 42 38 and 38 35 etc.... and of cousre dekalb tires putting 45 front left, 42 front right, 38 rear left 32 rear right..:fawk: SOOOOO....WHAT IS THE GOLDEN NUMBER...???
Over 40psi is a bit high. I used to use that when I was autox'ing on my street tires. I would suggest mid 30's and play around with it.
35 for normal cars/drivers....40 for WRX, and depending on the driver...either 40 to 45 for the STi or WRX's with 17's and up.
Peak grip on the RE070s is at about 40 PSI, you should be running about a 4lb stagger between the front and rear.
That is not true at all, what will destroy you're tires is running them at the wrong pressure period. When you run the tires at peak grip levels, you use all the tire and they wear out very evenly, combined with a proper alignment obviously. When you run them at the wrong pressures, you kill the edges or the middle.
I understand what you are saying. My point was just that when you are driving aggressively or racing on street tires its good to up the tire pressures, but leaving them up for daily driving is not the best idea.
^ Even if that's so, I'd only do it on dry pavement. I remember after an autocross I had pumped up the tires somewhere around 38 or 40 (staggered of course) and I had forgotten to take them back down to whatever I had been running them at. Well I ended having a long interstate commute that night in the rain, and let me tell you, it was just about the only time I've ever felt unsure of my traction. Granted I don't really remember the exact pressure I used (maybe it was too much). All I'm saying is that what feels great on a dry parking lot isn't the same on every surface.
When I used to autox on street tires I would run low 40's, but I would always drop them back down to about 35psi and my tires still wear evenly, but lasted a lot longer.
Why run staggerd pressures?? I see some people run higher in the front and some run higher in the rear. Just curious Thanks
Having really high rear pressures makes the tire really stiff, which doesn't allow for any roll under load. So it makes it a little easier to break the rear free, but it will eat the tires up pretty fast. Too high of tire pressures in the rear, and you decrease the contact patch, because it will bow the tire out in the middle of the tread.
so....about that magic number?!? haha told ya this is what I've been gettingg. everyone telling me different stuff
I've always tried to keep it between 34-36, but that is just my personal preference and slightly dependent on tires.
Every tire is diffrent, I suggest you start at 42f 38r. From there you are just going to have to play with it, there is no magic number for all tires, each brand and Ill even go so far as to say each production run needs a diffrent amount of air. Matt
i just put some 225/40R18 in my wrx. i put the pressure at like 32 front and rear and the handling sucked badly. the rear of the car was swinging out on turns and the front was screeching. finaly after heating the tires up it started handling better. i am going to up the psi to around 38 or 40 and see what happens.
I've been running 36f, 34r cold pressure on my RE070's... is this too low(door sill states 36,32)??? Also, don't understand why some are giving pressure levels while hot.. Wouldn't that vary greatly by exactly how hot? Wether its aggresive driving or Hotlanta heat I would think it would be hell to get a constant. To me, cold would be a lot easier to do (I live right next to a gas station)...
Correct me if I'm wrong but.. In a larger size tire, like a truck tire, there is more volume to fill and the pressure can be lower like 30psi or less. In a smaller tire, like a bike (pedal) tire, the volume is so small that tire pressure may need to be close to 100psi to maintain tire shape. My stock tires are 205/55/16, and the sticker reccomends 33 front 30 rear. Most Wrx's have narrower profile tires like 215/45/17 or 225/45/17 in the sti (right?) so I imagine the pressure would need to be higher, by how much I don't know. Stephen has even narrower profile tires with the 225/40/18. This size means that it is the same width as a 225/45/17 but has less volume thus it would need higher pressure to maintain tire shape. This is probably why handling sucked at 32 psi.
The volume in car tires is not relevant, I understand you're thinking....but you're over thinking it. Honestly you guys are over thinking tire pressure. Hot is when tire pressures are important, if the tires aren't hot you shouldn't be pushing it anyway. You should know what you're cold pressure is and what you're hot pressure is but you should always base adjustments on hot pressures. Matt
Nitrogen doesn't change as much. It works best if the tire is seated with nitrogen as well and most shops don't do that, Butler certainly doesn't. I see 2 to 4 psi pressure increases with nitrogen and 10-14 psi with air.