Tires & Wheels Ask all of your Tire & Wheel questions here!
Sponsored by:
Sponsored by:

18" - 124's - Tire Pressure

Old 02-08-2017, 06:24 AM
  #1  
Contributors
Thread Starter
 
Hyper_545i's Avatar
 
Join Date: Jan 2008
Location: New Jersey
Posts: 1,335
My Ride: 545i
Model Year: 2004
Engine: N62
Default 18" - 124's - Tire Pressure

Hello All,


I know there are a ton of topics regarding the air pressure recommendation on the E60's. The recommendations seem to be all over the place. I am just curious what the members on this forum are running and what the recommendation is. I used to run 36/38. I am now running 38/38. It feels like ti handles better, but the ride is a little harsh. I would love to hear what other members are running on the 18" 124 Sport wheels with 245/40/18 and 275/35/18 non-rft tires.


Thanks in advance!
Hyper_545i is offline  
Old 02-08-2017, 06:43 AM
  #2  
Members
Senior Members
 
Join Date: Jul 2008
Location: Atlantic Beach, Fl
Posts: 398
My Ride: e60 530i e21 320i
Model Year: 2005 1981
Engine: M54 M10
Default

Per BMW owners manual 04-05 545i tire pressures with 18" staggered.

Max 4 people. 32psi F. 35psi R.
4-5 people + luggage. 38psi F. 42psi R.
jtbgonesailing is offline  
Old 02-08-2017, 07:02 AM
  #3  
Contributors
Thread Starter
 
Hyper_545i's Avatar
 
Join Date: Jan 2008
Location: New Jersey
Posts: 1,335
My Ride: 545i
Model Year: 2004
Engine: N62
Default

Originally Posted by jtbgonesailing View Post
Per BMW owners manual 04-05 545i tire pressures with 18" staggered.

Max 4 people. 32psi F. 35psi R.
4-5 people + luggage. 38psi F. 42psi R.

Thanks for the reply! I know what the manual recommends. I tried the 32/35 and it was way to soft. I am assuming this was the recommendation with rft's. I just wanted to hear what other members were running as far as tire pressure.
Hyper_545i is offline  
Old 02-10-2017, 05:14 AM
  #4  
New Members
 
DanielFD's Avatar
 
Join Date: Mar 2013
Location: Lebanon
Posts: 236
My Ride: 2007 BMW 550i
Default

No deference in tire pressures between rtf and non rtf. In general a higher rear pressure means your car leans towards oversteer, more pressure in the front and more understeer. What adds more to all this is the way ARS works. under a set speed (i think 80 kph) the ARS system works so that the car has more understeer then oversteer, this is so the car is more comfortable to drive. Over a set speed the car becomes "neutral" where a balance is made between understeer and oversteer. Playing with air pressures is going to effect that feel. This is not say you shouldn't, what you should do in my opinion is try and see what makes you comfortable. I'm a bit OCD, and i like to think BMW is smarter then me so I stick to what they say, that makes me comfortable. 32 35 for me, also the roads here are terrible and my car is lowered on Eibach springs and i'm running on Msport shocks, the car is tight enough already!
DanielFD is offline  
Old 03-08-2017, 08:24 PM
  #5  
Members
 
Join Date: Aug 2012
Location: DFW, TX
Posts: 206
My Ride: 2009 535i Sport
Model Year: 2009
Engine: N54
Default

Different tires can vary greatly in the sidewall stiffness and construction.

Hyper, you are correct in thinking the RFT's at a given pressure will feel more accurate/responsive on turn-in - the sidewalls are incredibly stiff. This steering feel they provide in turn-in is the single advantage of RFT's in my book.

To get that same feel out of non-RFT's of the same size, you'd have to run more pressure in the tire. This could cause uneven wear if you go too high.

In my 535i with 18" 124's staggered, recommended pressure is 35/39. I find that 36/39 suits me. However the 545i is heavier on the front, and overall, so I'd expect you to need more pressure up front, and possibly in rear, than I would to get the same feel.

Originally Posted by DanielFD View Post
i like to think BMW is smarter then me so I stick to what they say, that makes me comfortable.
Everything a manufacturer builds or recommends is a compromise, to find a middle-ground average that will please the most people or reduce their liablity or make things last longer. Doesn't mean it pleases enthusiasts, performs the best, or provides the most comfort ... and certainly doesn't mean it's the best way.
LessIsMore is offline  

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.