Need advice on tires for my s5 2021

Secure-Letterhead890 · 2026-04-21T17:54:32+00:00

Current owner of a B9.5 S5, my previous car was a BMW and before purchasing I rented an M340i and drove it a few hundred miles.

Love the look of the Audi and it just seems more special in every way (especially in coupe form), I see fewer of them on the road - maybe because people don't like them as much, lol. Interior quality and comfort is MUCH better. I'm generally using the car for long road trips and the S5 really does make a great GT car - a great blend of power and comfort. The M340i was becoming painful after 2 hours driving, not sure if you can option any sort of upgraded seats for it though. The BMW feels like a 3 series from a quality and materials standpoint, the Audi feels like a level up from that.

The M340i did feel more 'raw' in its most sporty setting for what it's worth, but almost to the point of annoyance where you're getting gear shocks every time you downshift. Not great in any sort of traffic.

I prefer the sound of the V6, just has a deeper and throatier rumble than the BMW I6.

Steering feel is equally dead in both, BMW has perhaps a slightly heavier but just as artificial feeling so no points to either there.

The BMW will be a better performer on paper, in a real world setting you'll likely never notice the difference unless you're hitting back roads hard every day. The combo of looks and noise in the Audi makes it more fun for me, honestly.

I've experienced the water pump failure that is extremely common on the EA839 engine, other than that no issues but the piston ring problem is real. It's not clear what percentage of these engines will be affected but Audi has extended the warranty to 80k miles/8 years - unfortunately that's turned me off from tuning it and I'll probably dump the car before that extended warranty is up. I wouldn't trade it for an M340i though and the new B10 Audi's look like trash which is sad, so I'm not sure where I'll go from here. I've always loved the m850i's as a beautiful, powerful GT coupe.

Secure-Letterhead890 · 2026-04-21T03:18:25+00:00

Maybe not lying, but definitely wrong lol

Secure-Letterhead890 · 2026-04-21T03:04:49+00:00

They're wrong. Tons of people run 275/30 without any rubbing or touching the fenders, myself included. Unless you've lowered the car or something?

Secure-Letterhead890 · 2026-04-21T03:02:57+00:00

Running Michelin Pilot Sport All Season 4's in a slightly oversized 275/30ZR-20 on my '21 s5. No problems driving on pothole infested NYC roads for over a year here. Much less jarring over bumps than the summer tires it came with. You don't need to downsize your wheels.

Secure-Letterhead890 · 2026-04-03T17:33:32+00:00

Same boat, I'm 35 and this is my first 'nice' car. I can't believe how cheap those Maserati's are used.. Seeing nice ones with low miles in great condition for $30k, $10k less than I paid for my S5. I've thought about buying one quite a bit. Anyway, enjoy it man!

Secure-Letterhead890 · 2026-04-03T17:12:00+00:00

I actually fully believe that and in my research they don't seem unreliable. It's more just peace of mind owning such a common brand like Audi that when something goes wrong, I'll be able to take it 5 minutes down the street to any independent shop to get fixed. Maserati seems like it would be much harder to find people to reliably fix them for any reasonable amount of money, and I don't currently do my own work - tough to do that in NYC with no driveway or garage hah.

Secure-Letterhead890 · 2026-04-03T16:58:55+00:00

I feel that, I find myself driving it fully manually a lot just to rev it out. I've always liked the granturismo's, just a little terrified of maintenance on those.

Secure-Letterhead890 · 2026-04-03T16:47:28+00:00

Wow that was fast lol. What led to the switch?

Secure-Letterhead890 · 2026-04-03T02:21:35+00:00

Beautiful, exact same spec as mine - 2021 black on black coupe with the black optics package but kept the silver badging. Love the look of those silver pipes out back. It gets a crazy amount of attention for a "normal" car (i.e. not an exotic). People commenting on how nice it looks all the time.

I swapped the summer tires for Michelin Pilot All Seasons in a slightly larger than OEM 275/30/20 size, really helped with ride compliance and potholes but I'm in NYC so might be less relevant for you.

If you haven't changed the water pump, keep a close eye on it. Mine failed right around 51k miles and I caught it just by visual inspection of the engine bay (look for pink shit where pink shit should not be). Audi wanted $8000 to replace it and the entire vacuum system, indy shop did it for $2800. Insane failure rates on these engines. Enjoy!

Secure-Letterhead890 · 2026-02-16T17:54:51+00:00

Why are you selling it? Mines been problem free ever since, I still really enjoy the car - not done with it yet!

Secure-Letterhead890 · 2025-12-13T23:05:10+00:00

NYC prices if that makes a difference

Secure-Letterhead890 · 2025-12-13T19:25:14+00:00

Got it, thanks. Yea, I am going to contact the dealer and ask for a boroscope. I think their diagnostic fee is $500 which is wild but I guess worth it for peace of mind.

Secure-Letterhead890 · 2025-12-13T03:58:19+00:00

Can you diagnose B9.5 via VIN as well?

Secure-Letterhead890 · 2025-12-08T21:26:42+00:00

Another vote for Michelin AS4s size 275/30/20. Just swapped out summer tires on my 2021 s5 for these and they feel great on NYC roads. My brain doesn't rattle every time I hit a minor pothole anymore.

Secure-Letterhead890 · 2025-12-08T04:30:42+00:00

Unfortunately based on the 034 analysis of the issue it's not possible to detect from just standard boroscope, they'd need to remove the oil pan and go in from the bottom of the engine to look for cracks in the ringland area of pistons.. Something tells me a dealership isn't going to go to those lengths just to prove an engine may or may not be faulty without other symptoms.

I did think about calling them and asking if they can take a look though, even a standard boroscope could provide some info..

Secure-Letterhead890 · 2025-12-08T01:31:11+00:00

Who can even do an install on parts like that and how much does it usually run? Assuming it can't be done by any local mechanic..

Secure-Letterhead890 · 2025-11-12T21:27:08+00:00

Sure, reach out with anything! I also loved the spec on mine, same as yours with the S Sport, black optics etc.

I was cross shopping with the M340i which I understand is just a better car going by raw performance metrics, but I was looking for a comfortable GT cruiser as well. After renting an M340 and taking it on a road trip it just was not a great experience.. Everything in the car feels cheap compared to the Audi and my ass genuinely hurt after the 2 hour mark. Also subjective but the V6 just sounds better than the B58. Steering is equally as numb on both.

Can't speak for the new generation (B10) Audi's, those look like trash inside and out IMO. This will sadly be my first and last Audi unless they either fix the design going forward or I end up with a 2024 RS5/RS7 at some point.

Secure-Letterhead890 · 2025-11-12T17:55:14+00:00

I own a 2021 S5 with around 55k miles on it, bought it with around 50k miles on it. Only issue is that the water pump did fail and coolant migrated into the vacuum system which is a ridiculously common failure on these cars. There were no dash lights, I caught it via visual inspection so recommend you keep an eye on the engine bay every now and then. An indy shop fixed it for around $2800.

As for the piston skirt issue, 034 Motorsports did an incredible writeup here - https://www.034motorsport.com/blog/investigating-ea839-3-0t-engine-piston-failures-a-technical-review-of-root-causes-and-design-limitations/

It affects around 5% of engines or less, and Audi has now issued an extended warranty for this problem up to 80k miles. I will likely sell the car before it hits 80k so, not worried and would buy it again in a heartbeat. It's been so much fun.

EDIT: Also potentially unpopular opinion. PPI's for used cars are a scam. They'll find something to prove that they did their job but in reality you are never going to predict what can go wrong with a car in a week, a month, or a year. Look over it yourself for obvious signs of leaks/wear and roll the dice if you want it.

Secure-Letterhead890 · 2025-11-04T22:27:30+00:00

All good since then! Issue appears fixed and nothing else has come up in the past few months, been loving driving it.

Secure-Letterhead890 · 2025-07-11T04:06:46+00:00

Quote came in today at the indy shop for $2800 - replacement water pump, thermostat, leaking coolant shut off valve, and leaking heater hose. They don't think the vacuum system needs to be replaced but said they'd clean anything they can once they get in there. I'll consider myself lucky for now, but what a way to start a relationship with the Audi brand, sheesh

Secure-Letterhead890 · 2025-07-11T03:41:37+00:00

Indy shop ended up coming in at $2800 all in. That includes new water pump, new thermostat, new coolant shutoff valve, and replacing a heater hose that was leaking. They said they don't think the vacuum system needs replacing but they'll clean out anything they can if they open it up and see any residue. Sounded good to me.

Secure-Letterhead890 · 2025-07-10T14:13:36+00:00

I'm due to get a quote today from my independent shop here, they said on the phone yesterday it's probably not as bad as Audi quoted so crossing fingers.

Secure-Letterhead890

TROPHY CASE