Different Tire Pressure Recommendation for Automatics? (540i vs 540iA)

[theshadow92]

Is it just me or does it look like BMW recommends different tire pressures for automatics? Why is this? Added weight of an automatic?

[edjack]

Looks the same to me: 30/35 and 36/44. The difference is due to different tire/wheel sizes and suspension setups (all 540i/6 cars have sport suspension).

[theshadow92]

It looks to me that a 225/55 R 16 95 W tire would need 35/39 in a 540i whereas the same exact tire would need 30/35 in a 540iA, no?

[edjack]

Again, it depends on the suspension calibration. Try both, see what you like. I run 36 all around. Suits me.

[theshadow92]

Bump. Car is sitting on Koni Yellows (with original springs) and Continental Extremecontact DWS. 30/35 seems a little low, especially for the front with such a soft sidewall and stiffer shocks/struts.

[edjack]

Why not experiment until you find the pressures that suit you? Have you tried 36/36?

[dannyzabolotny]

Back when I had my 540i/6 I initially ran my wheels at like 40/40, but then I realized that it made the ride way too stiff with 18" M-Pars, so I lowered it to 32 all around and it felt so much better. I'll never inflate my tires past 32 ever again.

[philly98540]

You can risk a rim ding if you go too low. Tire sidewall plays big here. I've been happy with 35 psi with 275 18's front and back.

[ViolinARC]

2000 540iA with staggered 17" Style 32's here...I like 36psi up front and 42psi for the rear. The ride is nice, the wear is even and I want to get as much tread life as possible...