Tyre pressure
 

Hi guys,
Just trying to figure out what tyre pressure u guys been using on 20" run flats.
I'm from Sydney and most roads are littered with potholes and recycled concrete, don't get a smooth ride.
Recommended dose is 40psi but I'm running on 35psi expecting to have better flex on the tyres. What's ur opinion? I don't wanna change wheel size or go back to 18"

Use what works for you and how/where you drive.

(funny, no matter where people are from, they think THIER roads are bad.... Drove many thousands of miles in Sydney and nsw, roads seemed pretty decent!)

The "recommended" number is for an fully laden x5... How do you load it most of the time?

A

grey,

I'm not sure where you see 40 psi recommended. Recommendations over get over 35 psi for heavily laden X5's going over 100mph / 160 km/h.

As per Owner's Manual and the sticker on door, I have mine at 32 psi in front and 35 psi in rear.

I have the sport package (staggered 20" wheels) and third row seats.

EDITED after reviewing Owner's Manual...

I have 20" Bridgestone Dueler HP Sport RFTs and was running 36 psi all around. But I noticed this doesn't provide the best "even" tread wear. So, I changed it to 41 psi all around and noticed an improvement. Went to get a new alignment for "even" tread wear and they recommended 40-44 psi.

Here's the detail from the 2008 X5 Owner's Manual that says
1. 32 psi in front and
2. 35 psi in rear
for all 20" wheels for X5's with third row (whether 3.0si or 4.8i and with or without sport package).

If you only have two rows of seats, it's 32 psi all around...

On most of my cars I generally run a couple psi more than the factory recommended placard values. On our X5 this put excessive wear on the center of the rear tires (315s). Be careful to not over inflate and watch tire wear.

any advice for non rft? i was running recomended pressures psi( 32F/35R) on my toyo proxes STII-20 inchers, but after 1000 miles, the front seems to have some abnormal wear on the outside tread.... should i inflate 35psi even front and back. Car load is generally just me and wifey, 160lbs + 100lbs.

My guess would be your alignment is causing the outside wear on the fronts. My wife's factory tires were destroyed on the outside edges due to the high toe-in. How did the last set of tires wear?

Could be alignment, could also be overly aggressive cornering.

the car is new, i removed the rfts off immediately and mounted the toyos...do i still need an alignment?

I don't really drive aggressively...ill take some pics when i can