What to look out for????

[Kong9999]

Sorry, Jayhawk. I was typing while your newest note came in, but here's my reply.

My understanding is that a softer (lower PSI) tire will break loose sooner than a harder one, all other things being equal, and that this is because the softer tire's tread will squirm and start lifting off the pavement sooner than the harder one. I'm talking about street tires here, not drag radials, which are intended to flow around and into the texture of the pavement to deliver more than 1 g acceleration (and whose sidewalls wrinkle like cellophane).

More pressure is good only up to a point. A seriously overinflated tire will lose traction because the center of the tread will bulge, taking weight off the edges of the tread. Making the tire harder also ask more of the shocks to keep the tread on the road, rather than bouncing. This is even more serious if it's the front tires bouncing, because you then lose steering capability as well.

Meanwhile, M-B always tells you to put more air in the rears than the fronts, despite the fact that the front tires carry more weight in at least most models. Tire makers in turn follow car makers' recommendations very closely.

Swapping the F and R numbers you report would be in line with M-B's general approach, and with what both theory and experiment suggest to me. Going to 33 f and 36 r should give you more balanced handling and less nervous steering.

My experience under controlled performance-driving conditions (in the other car to which I refer from time to time) is that I'm more likely to experience oversteer if I don't put up the rear pressures a bit relative to the front.

Powerful RWD cars whose power gets used wear the rear tires faster than the fronts (even the 4Matic cars apply more torque to the rears, and I've observed more tire wear at the rears on my car). Having a bit more pressure in the rear will moderate this differential wear a bit. Again in my experience, letting the rears get soft in a powerful RWD car results in more squirming and wheelspin under hard acceleration.

Sorry if this doesn't add up to a hard-and-fast commandment. All I can do is share what I know and understand; the choices are yours.

[Skylaw]

A contributor asked a question related to which year of W220 to select, from '03 on. I thought the response had relevance to this string, so I'm posting it here too. Sorry for the duplication, but it does expand a bit. The lead-in to each paragraph identifies what his questions were.

Regarding reliability, bottom line is, the '03 model year saw the beginning of quality improvements, and most of the mechanicals were done by '04. Electronics improvements continued through '05 (which is nearly identical to '06). See http://www.benzworld.org/forums/w220...5-s500-4m.html and especially post #3 at differences between 2004 S 500 2006 S 500 - MBWorld.org Forums

Regarding adding an iPod, if you buy an '04 or later (these have MOST-based COMANDs, easily identified because it has a DVD-based navigation system with a reader in the trunk), you can use the Dension Gateway 500 for MOST bus. You will have steering wheel controls, and the text-capable COMAND gives you song titles on the COMAND screen and track info on the instrument cluster. With that, the Dension Gateway 500 is a very useable iPod option. See Gateway 500 for MOST – Good Unit, Poor Documentation - MBWorld.org Forums.

The '03 had an AUX input, but it is the only U.S. specification W220 (S-Class) to have it. See http://www.benzworld.org/forums/w220...tergation.html You only get the analog music feed with the AUX; you get no steering wheel control or readouts from the iPod. Sorting, song selection, and reading song titles must be done on the iPod; but the 3.5mm stereo cable is dirt cheap.

The '03 is the only U.S. W220 that can be fitted with the MB/Apple iPod kit (which provides steering wheel controls, and song titles on the instrument cluster display, but nothing on COMAND) - because the kit requires the AUX jack. Audio is better from the Gateway 500 kit, because it is a direct feed over fiber optics and escapes the compression MB designed into the AUX input.

The '03 has a wide screen COMAND, but is D2B based (it uses CDs for navigation, with the nav CD reader in the COMAND itself) and does not have a text-capable display. A Gateway 500 is available for the '03 and earlier W220s, but you will not get song titles on the COMAND or instrument cluster displays. You get track information, but sorting and selection is best done with the iPod (which the GW 500 will let you do). You can still change tracks and volume with the steering wheel buttons.

The W220 comes with either of two types of suspensions: Airmatic, a pneumatic system; and Active Body Control (ABC), an hydraulic system with additional computer control. Both are complex systems that will require maintenance; both are responsible for the superb ride and handling of the W220. Airmatic systems on earlier cars tended to fail more often than on the '03 and later - the '04s and on are less problematic. However, there is no such thing a a "bulletproof" pneumatic suspension system. Seals and pumps will wear, and struts will have to be replaced. You'd have to do the same thing with standard shocks, too - but Airmatic will be more expensive. The system has been written about a LOT, so I'm going to invite you to read and digest some of what you have already seen - especially in some of the newer posts. Start with post #6 at http://www.benzworld.org/forums/w220...yes-again.html. The best protection is to become familiar with the early signs of airmatic problems, and fix them right away. Letting them go runs the cost up.

ABC systems provide greater roll control and eliminate any "nosedive" even with heavy braking (not that there is much of either with Airmatic). One failure point, subject to inspection and free replacement, has been a high-pressure line from the pump. They are not especially problematic, but like any complex system, they break - and any luxury car is expensive to repair.

Regarding any choices between an S500 and an S430, there was more differentiation in earlier models. S500s through '03 had more standard equipment (and still do), but some equipment on the S500 was simply not available on the S430. That changed in '04, with most of the equipment for the S500 (except, of course, the engine) available for the S430; but more was standard on the S500 than on the S430. Some of the biggest differences in standard equipment were wood trim and the quality of leather. I mention this just in case you come across a good buy on an S430 - which, while having less horsepower, still has a great engine. The S350 version of the W220 was a more recent introduction in the U.S., becoming available only for '05 and '06. It had been available in Europe for much longer. It has less power yet, but is lighter; it was sold only in the "short wheelbase" (SWB) version in the U.S. Some like its styling better than the S500 or S430 (all of which, in U.S. versions, were long wheelbase).

As to "what year is best" - it depends on your own preferences. An '03 or later will be more reliable, and a lower-mileage car in an older model year may be better than a high mileage later model. For electronics and telematics, '04 and later are better for Pod integration (with a 3rd party kit) because of song title readout and sound quality, but the '03 AUX makes adding an iPod cheap - but there is very little "integration" with only the 3.5mm cable; you'll need the the MB iPod kit for that (roughly the same cost as the Gateway 500 kit). Making up for lack of the AUX, the '04 and later models can play DVD audio tracks (but not video in U.S. versions!!!) and mp3 DVDs - you can burn your entire music collection to DVDs and not worry about an iPod if you wish (not my choice, but you can do it). For ease of cell phone integration and flexibility, the '05 and '06 are your clear choice (IF the car already has the handsfree option installed).

If the cars you are interested in do not have phone systems installed, you're really in for some "fun." See http://www.benzworld.org/forums/audi...ades-plug.html.