MP4.2+6.0

I have been through this with both the C5 A6 and the D3 A8. When variously the bigger motor, heavier versions come out in S, RS or something similar, that is when I jump in. The OEM bars w busings typically cost a few hundred dollars per axle, usually meaningfully less than the aftermarket bars actually when even available. The rear bar that can make the bigger difference on none heavy cars like Audis, and my experience has been that when I focus on one end specifically. OE bars give the option of buying only what you want, while a lot of aftermarket bars are sold as some kind of sets.

From both the D3 and C5 experience, basically there ended up being three levels of bars available (base, sport and S). For the Q5, so far I think that is probably two (2.0T and then the V6's and probably Hybrid (w/ higher weight)). Don't get the sense S Line is doing anything at the bar level. With the SQ, I expect a third level bar, and with the TDI probably it stays with the regular V6 bar set up.

Also once the 2013 parts listings come on line more easily I plan to look cross platform more. So far it looks like the S5 and the V6 Q5's are already at the same bar level and likely interchange. But there is no pick up there by itself (and a 2.0T set up could already migrate to a Q5 V6 set up). Causes me to want to look at the RS5 bar level once I can get parts numbers online there. Also found a listing that surprised me, seeming to indicate the A7 and Q5 3.0T's probably crossed over on the bars. That suggests looking at the S7 too.

First the Q5 has to get here with some miles, and hopefully by then the SQ5 will have landed and with better info on details like factory suspension upgrading.

A3gotBAK

Having taking out the rear sway, the bar is hollow. I currently have the ultra racing rear sway installed. URacing bar is much heavier piece VS the OE bar

MP4.2+6.0

The bars on my 2006 A8 are hollow too, both in the starting sport fitment and then the upgrades S8 fitment I went to. Found hollow references here and there as well when I was looking into Q5 fitments preliminarily. The torsional resistance is really determined mostly by the diameter, not hollow vs. not. The hollow wall thicknesses themselves do vary some with the diameters from my A8 experience, probably in part for stiffness finesse and part for longevity. From older Audi bars I have pulled by comparison, non hollow bars add a bunch of weight, especially with a front bar as they get close to an inch in diameter. Some smaller diameter bars, especially in back, may still remain solid stock though.

Wunsch

The STaSIS suspension that I have includes an upgraded rear sway bar, in addition to the springs. I had a front-wheel drive A3 with the sport package before this, and I can't really complain about the Q's handling.

rkdiddy

I might be wrong, but I don't think STaSIS will break up their kits - so if you want the sway you have to pay for the springs.

MP4.2+6.0

from the web pages I saw already. Another reason I'll be looking at the SQ5 for the donor sway parts if they upgrade them as is typical for an "S."

acadianbob

That's right. I emailed them and that's the response I got. I'm going to wait for SQ5 parts.