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Justin e36
10-15-2005, 06:22 AM
I think Mystikal would be best to ask this to, but I'll open it up for everyone.

I'm running Yokohama ES100's. 225/40/18 on the front and 255/35/18 on the rear. What's the proper PSI for street driving for the front's and rear's? The vehicle is lowered on Eibach springs & M3 struts/shocks.

J

paul christians
10-15-2005, 08:14 AM
I would go with 34 to 36 at the most....

JazzM
10-15-2005, 09:19 AM
Depends on your alignment settings (camber)

Most people will prefer around 32 front and 34-36 rear.

T.

Darkness95m3
10-15-2005, 01:23 PM
I think Mystikal would be best to ask this to, but I'll open it up for everyone.

I'm running Yokohama ES100's. 225/40/18 on the front and 255/35/18 on the rear. What's the proper PSI for street driving for the front's and rear's? The vehicle is lowered on Eibach springs & M3 struts/shocks.

J

I'm running on the 5 Series 35Psi all around.

rodo
10-15-2005, 01:45 PM
what about me? 225/45/17 all around sports pck. rims, running 32 in front and 34 in rear how does that sound? BTW ive sports pck. so I've the sports package suspension

Kal
10-15-2005, 03:45 PM
I do 34. But lately, I've been pumping the air in the tires a little more as it saves on fuel consumption.

Mystikal
10-15-2005, 08:18 PM
So many tire variables, so many "ideal" pressures for different situations, so many personal preferences.

Start with BMW-recommend pressures for the 17's (should be on your car and/or the manual), and work upwards, generally 3psi at a time. Get a feel for each, see what you like. You can seriously change the dynamics and balance of the car with just pressures, what that staggered setup I'd probably be getting very creative with front-rear balance (likely a large difference), but again, without driving it hard I wouldn't be able to tell you.

Understated
10-15-2005, 08:21 PM
what about me? 225/45/17 all around sports pck. rims, running 32 in front and 34 in rear how does that sound? BTW ive sports pck. so I've the sports package suspension

pardon my ignorance but why would you have diff psi's setup for front/back unless you had a staggered setup....i don't understand the difference it would make :confused:

Mystikal
10-15-2005, 08:30 PM
pardon my ignorance but why would you have diff psi's setup for front/back unless you had a staggered setup....i don't understand the difference it would make :confused:

Weight. As you pile people and junk inside the car (and trunk), you're moving the weight balance towards the rear of the car, not to mention putting more pressure on the sidewall of the tires. Having the extra PSI in the rear adds more dummy-safe understeer (to compensate for the rearward-bias) and protects rims from bending.

rodo
10-15-2005, 08:52 PM
yah, the guy at budds told me to use those pressures, and the back doesn't swing around now, before i pumped them up i could make it swing oh so nicely, but not any more:( would you recomend i still use 32 front 34 rear or something else? Thanks bro!:)

Understated
10-15-2005, 08:54 PM
thats sweet...thnx for the info...and thsi is the same for all types of drives right?(AWD, RWD and FWD?)

Antz_Marchin
10-15-2005, 09:28 PM
I would go with 34 to 36 at the most....


Exactly what I use. Staggered LTWs on an E36 M3.

Mystikal
10-16-2005, 03:49 AM
thats sweet...thnx for the info...and thsi is the same for all types of drives right?(AWD, RWD and FWD?)

Not necessarily. Other cars (especially front-engined ones) aren't nearly as close to 50-50 distribution unladen as a BMW, so they can get away with more neutral front-rear pressures; this is simply because even with extra weight towards the rear of the vehicle in a heavy load scenario, it's still not nearly as unbalanced as a BMW with the same payload.

Jon@Bimmersport
10-16-2005, 11:38 AM
what about my car? i added 2 12s in a box and amp in the trunk?

Mystikal
10-16-2005, 05:13 PM
Meh, you'll stuff it sideways into something no matter what I tell you. Haha!

I can't really suggest anything, as soon as some part of the car is modded (suspension ANYTHING, weight moved, even new tires of coruse), your pressures should be changing to seek a desired handling balance and/or ride quality.

rodo
10-16-2005, 05:20 PM
what happens if i have a higher pressure than what the bmw guy suggested?

Mystikal
10-16-2005, 05:26 PM
what happens if i have a higher pressure than what the bmw guy suggested?

Stiffer ride, less sidewall flex in cornering, and if you take it too far uneven wear.

sirex
10-16-2005, 05:48 PM
So the reason for this weird 32 in the front 34 psi in the back is because BMW's are bad at weight redistrubution when loaded up is that it?

rodo
10-16-2005, 06:44 PM
so a bit more pressure and a better handling ride then eh? and in my aviator the guys at the dealership said 32psi but sometimes it squeals when turning when it def. shouldn't and the back feels sloppy as hell when u jerk the steering wheel, should i pump them up more? if so how much?

Mystikal
10-16-2005, 10:07 PM
So the reason for this weird 32 in the front 34 psi in the back is because BMW's are bad at weight redistrubution when loaded up is that it?

It's one of the main reasons, though not the.

Mystikal
10-16-2005, 10:10 PM
so a bit more pressure and a better handling ride then eh? and in my aviator the guys at the dealership said 32psi but sometimes it squeals when turning when it def. shouldn't and the back feels sloppy as hell when u jerk the steering wheel, should i pump them up more? if so how much?

IMO, factory-spec ratings are far too low for hard driving, especially with the non-agressive rubber fitted stock.

And the Aviator will always feel like that, it's a bonus of owning a two-tonne behemoth with a high centre of gravity and 7" sidewalls. Enjoy!

bmwm5lover
10-16-2005, 11:13 PM
I run about 35PSi. I like it stiff, what can i say LOOLOL

Justin e36
10-17-2005, 12:05 AM
I like it stiff, what can i say...

:huh?:

Mystikal
10-17-2005, 02:36 PM
I run about 35PSi. I like it stiff, what can i say LOOLOL

35psi is wayyyy too mushy for me.

With the 14's I ran 42 typically, with the 16's now I'm still playing around but at the moment 38psi seems a little slow to respond. And I'm sure my tires have MUCH stiffer sidewalls than yours. :P

I cup outer shoulders when I don't run these pressures.

SebSter
10-17-2005, 02:46 PM
I actually had it aroudn 30 before reading this thread (on my 16s). I pumped it up to about 38 all aroudn after reading this thread, feels much better in terms of handling hard turns, and even a little different off the line acceleration...though the ride quality is much much stiffer.

Gamite
10-17-2005, 04:43 PM
u don't want to over inflate either, cuz then you're tire is going to bulge in the middle.

bmwm5lover
10-17-2005, 05:53 PM
Now 40 rear, 38 front. Or sumting like that

Mystikal
10-17-2005, 06:00 PM
u don't want to over inflate either, cuz then you're tire is going to bulge in the middle.

Yep. In my experience with all sorts of different sized and branded tires though, I've found that it takes quite high pressure to do that. I've run 43 consistently in different setups and never worn the centre tread more than the outsides. Again though, I drive hard and generally put more pressure on the outside tread.