Orange electronics - TPMS sensors

[A8CT]

No, just air filled. I did not go through MMI, I thought I read that they would auto detect after driving which they seemed to do. Went from all blank lines in MMI display to showing temps and PSI. The temps BTW all seem to be about right both before and after driving with the spare staying about the same. The sensors all have different ID's, I verified that and wrote them down. Let me check the MMI setup idea....

[MP4.2+6.0]

Hmmm. Presto, all fixed. Thanks Art in Engineering.

That would be the TPMS info that, now that I think about it, I don't recall seeing anywhere in the MMI screens on the D4 loaner...which in the small world I got during the TPMS sensor change out. Ditto on the battery meter taking a powder on the D4 IIRC. It did finally get the oil level reading enabled though.

Well, that's one way to "fix" a problem. Kind of like the old instrument gauge delete. Of course, I think they went w/ the "newer" indirect feedback loop from ABS sensors looking for differential speed feedback, though I seem to also recall other info saying those systems didn't provide reliable data in some scenarios. Presumably no temp data at all, and I don't see how they really get a reading about baseline pressure, other than to assume a default running circumference during a reset.

One of about a dozen "improvements" I found on the D4 that were basically deleting things, even though price is up a good amount over my D3. Found when I looked carefully a heavily optioned 4.2 can approach what the old base sticker was on a D3 W12, which itself was even more optioned and of course had the motor. But, like the D3 I expect the value to drop fast once they start rolling off leases and overrun the CPO price support, so maybe more compelling on the value equation as they age.

[MP4.2+6.0]

Seriously, Mishar is right. Even labelling aside, I have found on most any FWD or AWD variant of a FWD set up that more pressure in front relative to back improves front tire life, crispens steering and improves ride comfort (at least toward the back).

[mishar]

It has more to do with weight distribution. A8 is nose heavy.

[MP4.2+6.0]

The reference to FWD based systems was already meant to cover that.

[Brozee]

What is a setting for pressure that you recommend for the front/back?

[A8CT]

ok, just went out and reinitialized thru MMI. Drove for about 15 mins and then I had readings on all five tires. The spare was 36ish and three of the four were exactly the same. After driving another 5-10 mins all four are exactly the same temp.

I checked with my gauge and it's pretty close it just seems weird that all four are identical.

I'm going to give Orange a call now.

[A8CT]

for what it's worth, spec calls for 30 front and 33 rear.

[MP4.2+6.0]

W12's apparently have different pressure settings than 4.2. So "my" settings may not translate directly.

If your car is a pre-2007 and has the long standing German style pressure sticker with the settings for both lightly loaded and heavily loaded by tire size, start there. Picture of mine is attached.

My net is 40 front 38 rear on the W12 w/ 275/35 20's. BUT, you need to translate to your motor and tire size. By the way, notice at least on mine the oddity that the 18's AND 20's both run at lower specified pressures (even though it goes from 45's to 35's), while the 40 series 19 is actually higher than the 20's. Must interact w/ either width or the higher mandated 102 load rating (plus XL) in the 20's.

To translate to your car, I basically take the midpoint of the specified range from lightly loaded to heavily loaded and then round down slightly. I watch it for even tire wear over a lot of miles, plus decide if I am happy w/ the steering feel and ride. Steering feel both in how crisp it feels and smoothness. More pressure w/in the range is usually better for crispness in front, but it increases feedback (good and bad), the bad being undue sense of road vibration. Too much and you wear the tire center excessively as well. If instead I see front shoulders wearing excessively (they always wear somewhat more), I dial it up another 1-2 PSI. In rear, my prior tongue in cheek comment was you can actually play with oversteer/understeer slightly. It is subtle w/in normal parameters, but the classic example is way underinflated rears can make the back end twitchy in an over steer like way. Not predictable though, so you want to keep it in the range.

For readers with a U.S. spec car from somewhere in the 2007 era on, you now have the dumbed down NHTSA sticker courtesy of the Ford Explorer roll over debacle. Standardized sticker placed on the drivers B pillar w/ white background, black, red and yellow printing (all specifically mandated). That means one size (pressure) fits all for your model and as shipped factory wheel fitment. Not what they do in Europe. Sometimes the manuals have more/better info in that case, like my 2010 Mini S that gives settings for various models, load, driving speed, etc. Or, I look for the pre-2007 same model with the earlier more thorough info, or if all else fails look for Europe posts w/ their info unadulterated by NHTSA. First found this out by the way from a VW Phaeton board where posters suddenly realized the pressures they were debating didn't agree, and it tracked back to the pre- vs. post NHTSA sticker changed and that VW had basically jacked them way up on the newer stickers, apparently to comply w/ the max load rating under all conditions, rather than letting the owner decide.

[mishar]

Same thing 2005 A8L