mutant9

What's up everyone.

I just picked up a 2015 A8l 4.0t. I have a few questions as I am getting adjusted to the car and looking to make a few tweaks.

I have the 20" 10 spoke wheels, what size wheel spacers do you recommend. I have seen 17 mm front and 20mm rear on the S8s posted here but not sure if the offset on the 21s are different from the 20s.

Also what is the best way to lower the car without effecting the warranty. Can this be done using the OBD Eleven solution? I purchased an aftermarket warranty the does not allow for modification so I don't want to use lowering links.

Lastly any good tips on an aftermarket service contract? My credit union did not offer one for the car so I purchased one from the dealer (non audi dealer) its exclusionary but it cost $4800 for 2 years of coverage. I have 30 days to terminate with a full refund so I am on the hunt for a better alternative.

Thanks for the comments, I have read about 20 pages into he forum prior to making the purchase, great content here!

Thanks

collantes_C6

Hey. I'm on the same dilemma as well re the warranty. I'm still searching for a good 3rd party warranty provider here in Toronto (ON). I chose to include the Audi warranty, mechanical breakdown protection, for now and I have until the end of April to either proceed with it or cancel it. Locally, I have a couple of choices to consider. It's definitely half the price of what the dealership offered ($5k for 3yrs or 40k kms). I've read through the the fine print and it's almost identical to Audi's and the best part is, they're not limiting me to their own approved shops. I can go to Audi or my independent mech for repairs. However, someone also told me to just save the $$ and pay as you go considering I won't put it as much mileage since I use it only for work commutes and family errands. I have my wife's Atlas to do the long distance trips.
Anyway, I hope this helps to some degree.

MP4.2+6.0

Welcome.

On spacers, there are a bunch of threads over past several years, including ones I have participated in. If you want to get more technical, along the lines of your S8 vs. A8 question, yes S8 OE 21" wheels have a very slightly different offset in 21's. They also run a 275 tire, while the 20's are a very much an orphan limited choice size. See TireRack to confirm the generally slim pickings at not cheap prices. Many opt to go to 275's in 20's where there is way more choice and typically better pricing, me included. Search on threads if interested--use Google pointed at AW, not the sub par AW search. I would first decide long term tire size, then decide spacers. As in, if you use 275's, you would space slightly less.

You can lower with VCDS--typically up to 17mm though personally I think ride deteriorates by then and might be a little dicey on longest term reliability. I don't know if OBDeleven has that functionality. Since I have an S8, it's already 10mm down stock. If you opt for 275's that also reduces the wheel well gapping a bit (about .2 inches = 5mm) and increases ride height same--essentially allows a bit of actual dropping while keeping real world usable road height. Realize the D4 has a REALLY long nose and chin, especially if it has the S8 or sport bumper. Drive it a few weeks at least and see if you drag it at all stock.

Warranty: no data here since I bought CPO, w/ another year to go.

mutant9

Thanks for the responses! It has a new set of 275s on so I will do some measuring. Last question, are the lug bolts cone or ball shaped for oem wheels?

MP4.2+6.0

Audi OE bolts and OE wheels are ball type.

Waterflow

hello everyone,
I understand it is hard but could somebody try to explain how the engine suppose to sound on Idle on 4.0 2015th. Also, every short while I am filling a very low vibration going through steering wheel, is this something normal?
Thank you in advance!

MP4.2+6.0

Search for posts on 1000 and 3000 rpm 4.0T vibration--bad flex pipe joints in head pipes. If you find it at 3000 rpm too, you pretty much know you have flex joint disease. Warranty cure is new headpipes at dealer prices. Cheap non warranty is muffler shop to weld new standard jobber flex joints in.

TinyElviss

spdemon91

^ Mine also has flex joint disease,... bad. Been driving me crazy and is what actually led me to joining this forum to research the issue. It came down to two options for me... get the flex joints replaced at a muffler shop which would be the cheapest route or for $1,999 plus install, go with APR downpipes. I am choosing to go with the APR downpipes for several reasons...

1.) No Vibrations - Eliminates 1k/3k vibration issue.

2.) Heat Reduction - Replaces the wonky factory catalytic converters with high-flow cats and correctly places the cats further downstream thus helping to remove some significant heat from an already super-hot engine bay.

3.) Exhaust Note - Eliminates factory resonated midpipes which in combination with high-flow cats, contributes to a more aggressive exhaust note. Not looking for a super-loud exhaust, I already have that with my Viper, just looking for a more aggressive tone and slight increase in volume which these pipes provide.

4.) Horsepower - Downpipes are much bigger than factory pipes and thus freer flowing contributing to some horsepower gain.

MP4.2+6.0

Did your S8 first come from a CARB state? You are in one now (PA), and I bet a turbo back install is going to lead to TD1 7/70 CARB warranty punch, or at least give Audi an out. Post 7/70 even in a CARB state, it's all risk vs. reward assess, unless Audi ends up sued or chased down to a recall and reimbursement program later. You will clock out of 7 years fairly soon; backfilled forced warranty deals I have seen Audi do are maybe out to 10/100. Its a big picture low volume motor though, so Audi probably hopes they can bury and stuff it. IIRC you did the preemptive screen parts, etc. replace so may have enough data too be comfortable.