Lowering '02 A6 3.0 to '04 A6 S-Line stance
 

My 2002 A6 looks goofy. 1) the 16" wheels look too small. 2) it sits too high, especially in the front. I just bought a set of those 9 spoke 18" "Celebration" 58773 wheels as used on the '03/'04 A6 s line. Now, I just have to bring the car down a bit; I'm thinking almost 2" in the front and maybe only 1" in the back. Question is- how should I do it? I don't want the ride quality to change. How is the A6 3.0 and the 2.7 s line front suspensions different that makes the 2.7 sit lower? Different struts? For only 1" drop, I can probably just change out the springs?

Different spindles?

Get new springs. However, ride quality will change unless you get new shocks.
Chances are your 02 A6 shocks will be too soft for the lower (and probably higher spring rate) springs.

Same ride quality?
 

I have an 04 S Line with eiback pro springs and i think the same wheels you mentioned. You will end up with a lot stiffer ride and have to watch for potholes and such. Get an improved sway bar kit if you go this route and your handling will be incredibly different. Roundabouts at 50mph can be fun. But in my opinion, just a mean looking stance and somehow never attracts attention from the law (knocks on wood).

Thanks for the replies. Your '04 S line looks good! I'm looking to lower my car to where the centerline of the door bottom molding lines up with the center of the wheel, so my car will sit just a bit higher than yours. All I want is a stock A6 S line height. When it comes to spring rates and shocks, I'm not very knowledgeable. As I figured, when I lowered my '58 Impala by cutting off 1.5 of a coil from the springs, the ride got stiffer and harsher. How to lower my A6 and still end up with the same ride is a mystery at this point. I don't know what spring rates mean. Too bad the height isn't just all in the spindle, which you could just swap out while using your existing shock and springs.

And yes, those are the same wheels I just acquired, which I think look so good on these cars.

I am not sure that this can be done without 'ride quality' impacts, probably for better. If you put new rims on, the ride will change, then you adjust the suspension, your ride again must change with the introduction of new springs etc. Oh and the changes will most likely be for the better if you go with a tried and true spring combination and skip the track/racing setups.

You also need to look at the rubber you are buying for your new 18" rims. They will impact ride and road noise. These new rims will feel roads much differently than your smaller ones. Get some nice soft summer tires to minimize the difference in feel. All weather tires will be more expensive and harder. You will feel it. Of course, if your road conditions require all weather, you have no choice unless you want to get very expensive with a softer all weather that you will wind up replacing twice a year.

When you cut 1.5 coils off your 58 you essentially shortened the torsion bar…all things being equal that increases spring rate. On a torsion bar it's measured in newtons or pounds per radian or degree, on a coil spring it's force/length. Problem is that if you lower the car you have less distance before the suspension bottoms out so you still want to have the same force at this compression point which generally means a higher spring rate. There are progressive springs that have a weaker spring rate for the first inch or so and then stiffen up, thereby attempting to maintain some ride quality.
You might find that a quality set of 'coilovers', technically aftermarket adjustable coilovers because your stock ones are nonadjustable coilovers, will improve ride quality. It's all in the beholder.

I am a big believer in after market coilovers. They will change the ride of your car. This is not a bad thing.

Could the "red shock" sport strut assemblies be installed in a non-sport suspension? I could get complete used sport suspension strut assemblies. Or, in an effort to go cheap and try to maintain the ride quality, could some of the bar just above the mounting bracket at the lower end out the strut be cut out and the bracket arc welded back on? All I want is 1" - 1.5" drop at the wheel, so I figure removing about 3/4" from the shock would get me in that range. Wonder if this has ever been done before. It's not a big drop, so I don't think there would be risk of wheel bottoming out.