pabskamai

Hi,

Brand new at this forum, currently thinking about purchasing a used 2013 or 2015 Audi RS5, do you have any advice for me?

Also looking at a 2008 Audi R8 or a 2013 Porsche 911 Carrera 4.

Thanks,

Ape Factory

I'd skip the R8 as the early ones can have structural issues. The RS5 actually handles better too. The 4.2L in the R8 is also an older design from the RS5 (see below) and the RS5's engine, called the CFSA, is a new design. No comment on the 911. It's a much lighter car but I'm sure maintenance is through the roof compared to the RS5.

As for the RS5, great cars that are pretty darn reliable. Tons of threads on this very subject but just a few pointers. First, make sure the car has maintenance records and all factory services completed by a dealer or independent shop on time. The RS5's maintenance schedule is more complex/frequent than the S5 with the gearbox and rear differential needing regular maintenance.

Some cars with the standard iron rotor brake setup can have issues. Depending on far along towards issues they are, it can be solved by either aftermarket brake pads and/or rotors. Not all cars suffered from brake issues. Ceramic rotors are optional (fronts only) and they're exceptional. The new Lamborghini Hurican Performante uses the exact same rotor/caliper and a slightly different pad compound just to give you an idea of how good they are despite their age.

The A5/S5/RS5 can have front suspension bushing issues, mostly the upper control arm bushings. With all that weight up front, it's a necessary evil. But the actual bushings are like $11 each. They just tend to wear out with miles. Easy enough to replace.

There aren't a ton of "mods" for the car, mostly intakes, exhaust and suspension bits. If you can find a car that already has some modifications, don't let that stop you. Most owners swap out the OEM exhaust as the engine sounds so damn good. A good aftermarket system from AWE, JHM, Capristo, Akrvpovic, Klein, etc...really wake the exhaust note up. There's something for everyone's taste.

There's a good selection of chassis/suspension parts to choose from including Ohlins, Bilstein and KW which all make high quality coil-over kits.

Tuning wise, there really hasn't been much available that's worthwhile til now. JHM has their stage 1 tune out now and it made a solid 25hp on my car. I just carbon-cleaned my engine so it's probably making even more over OEM.

The engine itself is pretty much bulletproof. It's the R8's V10 with two cylinders lopped off. The rods, pistons, rings, bearings, etc...are all the same part number. We all know how well the R8 takes to supercharging and when tuned correctly, they're reliable. Ditto for the transmission. Some S-Tronics had issues prior to 2012 and if something does go wrong, it's an expensive fix. It's really rare anything goes wrong with proper maintenance and the 2013+ cars had a new mechatronic unit/heat sink which improved reliability.

With that said, the engine is direct injected. That means it'll need to be carbon cleaned at some point if you want to maintain peak performance. If you're mechanically inclined you can do it yourself. Otherwise expect it to cost around $1,000 to $1200 for the service. Some cars have gone 100K without carbon cleaning. I did mine at 50K and it definitely needed it. The car was definitely more powerful after the cleaning.

Servicing is more expensive than an S5. I change my oil every 5K, not 10K like Audi stipulates.

Other than the brakes, there weren't any major issues. Some have had smaller coolant lines running to the overflow tank crack. I've not had that issue yet and I live in a hot climate for half the year.

I would take your time and look for the car with the right color and options. There are very few differences between 2013 and 2015. I think the Mmi system received some kind of a mechanical update. They all use the same software. 2015's had a different 20" wheel option. They renamed some of the packages and I think some items became standard in 2014?

They're somewhat heavy, right around 4,000 pounds but they're rockets on real world roads. You'll always hear Audis understeer but on the RS5, if driven correctly, they do not understeer and in fact, you can get the tail to swing out, albeit briefly. It'll just launch out of corners on the gas. I find that the car can be a bit frustrating at normal speeds. It's so capable and it's limits are so high that it needs to be pushed to feel alive at times. But it's also a real cruiser/GT when you need it to be. Very much a dual personality car. I've done 800 miles in a day and the car just doesn't skip a beat.

Gas mileage is mediocre. I daily drive mine and I'm getting about 18mpg best case, currently at 15mpg mostly because I'm getting on it a bit more since the carbon cleaning.

A warranty is good if you're not mechanically inclined. I do not have a warranty on mine but I can also fix most things myself. I've not had a single problem with my car other an a squeaking aftermarket polyurethane bushing and the carbon buildup.

I'm sure others can add more.

pabskamai

Thank you very much for the level of details, this has definitively made my search much easier!!

Ape Factory

Most welcome! Report back when you've found a car. Also, there's a really large group of RS5 owners on the Audizine forum. We've seemed to have congregated over there. It can be a bit quiet round these parts in regards to RS5 content.

J. Patterson

Ape Factory

Revs and horsepower. The RS5 revs higher and makes more hp than the S5. People tend to keep the rpm level up on the RS5 when driving hard too. It's also tuned a bit differently and is more rear biased with different TCU algorithms which may lead to increases shearing of gear oil and the ATF hydraulic side has more work to do as well. I just changed both fluids in my rear diff and I can say that, at least by the looks of things, it was ready to be changed. I need to send the oil and atf out for analysis to confirm.

Now you may say, "Wait!" With a tune and a few mods, the S5 makes more hp and torque. Sure. Which is why, if your car is modded, you should probably change both fluids every 20K miles.

J. Patterson

Ape Factory

Probably not, actually. The RS5 generates a whole lot more heat in those extra 1300 or so revs and it's producing almost 100 more hp at the S5's redline. A stock S5 makes what, 333hp? The RS5 is at 450. And the RS5 continues to rev to 8300rpm and the torque curve is quite flat til redline. It doesn't seem logical but there's just more friction generating heat not to mention gear oil shear due to revs even . RS drivers tend to track their cars more or Audi builds them to be tracked more.

superswiss

Just adding on this. The sport differential in the S5 is only conceptually the same as in the RS5. They are not the same units. Because of the RS5 being a high revving engine, the SD in the RS5 has a higher final drive ratio and the revs going into the diff are higher than in an S5. Those higher revs combined with the higher HP put a lot more stress on the diff as @Ape Factory already explained. Don't underestimate the reinforcement required to cope with an extra 1500 rpm. The engine internals also have to be significantly stronger to handle those higher revs. The RS5 also makes more wheel torque than the S5. That's a function of that higher final ratio. A lot of people focus on the engine torque only, not realizing that wheel torque is ultimately what matters and wheel tq = engine tq * gear ratio * final drive ratio. The S5 has a final drive ratio of 3.682 whereas the RS5 has a ratio of 4.375. So to give an idea, the 325 lb-ft engine peak torque of the S5 results in 4388 lb-ft peak wheel torque in first gear, whereas the slightly lower 317 lb-ft peak engine torque of the RS5 results in 5120 lb-ft peak wheel torque, so in stock form the SD in the RS5 has to handle almost 1000 lb-ft more and if you tune your S5 you better deviate from the factory recommended maintenance schedule and do something about the higher stresses you are putting on the various components.

J. Patterson