B9 S5 Vs B9 RS5

Choosing a new sports car puts the Audi S5 and RS5 at the top of many enthusiasts' lists, standing toe-to-toe with their German rivals, the BMW 340i and M3. Making a decision can be quite the challenge with such high-caliber options on the table.

Once you lean towards Audi, there's another hurdle: figuring out if the RS5's performance justifies its nearly $20k premium over the S5. At first glance, the two cars appear similar, but the RS5 sets itself apart with a more sports-oriented look and a more aggressive stance straight out of the gate.

Let's dive into the key differences between the B9 Audi S5 and the B9 Audi RS5, shedding light on what sets these two formidable cars apart.

Related: Best B9 S5 Mods

KEY TAKEAWAYS

Power and Performance: The B9 RS5 outpaces the S5 with its bi-turbo engine, boasting 444 horsepower and 442 lb-ft of torque, versus the S5's 349 horsepower and 369 lb-ft of torque.
Body and Style: The RS5 features a wider body with broader front fenders and rear arches, giving it a more aggressive stance compared to the S5.
Seating: Sports seats come standard in the RS5, offering enhanced support and a sportier feel, but are available as an option for the S5.

RS5 Vs S5 Engine Difference

Under the hood, the B9 S5 and B9 RS5 might look deceivingly similar, but don't let the engine covers fool you—they house distinctly different beasts.

Although the turbo setup and engine volume is different the engines are based off each other. For those of you who like the technical side, here is a breakdown of the bore, stroke, cylinder spacing between the 2 engines:

Specs	3.0T V6 Turbo S5	2.9T V6 Twin-Turbo RS5
Bore	84.5 mm	84.5 mm
Stroke	89.0 mm	86.0 mm
Cylinder Spacing	93 mm	93 mm
Compression Ratio	11:1	10:1

The 2.9 liter engine is directly derived from the 3.0 liter engine. The displacement reduction to 2894 cm³ is achieved by shortening the stroke by 3 mm to 86.0 mm. Another change concerns the crankshaft main bearings, which have a 2 mm larger diameter due to the higher load.

Internal parts used are also different. The SR5’s 2.9T has different pistons, different crankshaft and a shorter stroke.

The Twin-Turbo V6 found on the RS5 has been built and developed jointly with Porsche. This very same engine can be found on cars like the Porsche Panamera and Porsche Macan.

Related: Torsen Vs Haldex Explained

RS5 Vs S5 Performance

Both the B9 S5 and RS5 deliver impressive performance right out of the gate. The RS5 takes the lead with a robust 444 horsepower sent directly to the wheels, while the S5 is not far behind, offering a solid 349 horsepower.

Although enthusiasts and testers who have taken these models to the dyno report numbers slightly higher than Audi's official specifications, for the sake of comparison, we'll focus on the factory-reported figures.

Related: Audi S5 Generations By Year

S5 VS RS5: 0-60 MPH

Specifications	B9 Audi S5	B9 Audi RS5
Engine	3.0-liter turbo V6	2.9-liter twin-turbo V6
Transmission	8-speed AT	8-speed AT
Power	349 hp	444 hp
Torque	369 lb-ft	442 lb-ft
0-60 mph	4.5 sec	3.8 sec
Top speed	155 mph	155 mph (174 mph Dynamic Plus, 180 mph Competition)
Price, MSRP	$56,800	$78,900
Price, Today	$25,500	$45,500

The Audi RS5 Sportback really shines with its quick acceleration, hitting 60 mph in just 3.8 seconds. The S5 Sportback isn't far behind, making the sprint to 60 mph in 4.5 seconds. If we look at the coupe versions of these cars, they're even a tad quicker, beating their 5-door versions by a tenth of a second.

Both the RS5 and S5 have their speed capped at 155 mph for safety. But, for those wanting a bit more thrill, the RS5 can reach up to 174 mph if you choose the optional $3,500 Dynamic package.

Now you might be thinking, does 100 more horsepower justify paying nearly 20k more for an RS5? The answer to that depends on what you’re looking to get with your car.

Related: Intercooler Ugprade Benefits

S5 Vs RS5: Handling

The Audi RS5 really shines with its sporty tweaks - think tighter suspension and a lower stance. This setup makes it nimble and quick on its feet, but you might not feel much of that zip in regular driving.

The S5 goes a bit easier on you with its steering and suspension. It's like the RS5's chill sibling, giving you plenty of oomph but with a smoother ride, and it doesn't hit your wallet as hard.

Now, some folks in the S5 camp might catch themselves daydreaming about the RS5's beefier twin-turbo boost. In plain speak, while you can spot the differences if you're really looking, they don't make a huge impact for most drivers, especially if you're just zooming around town or cruising on the freeway.

For your average drive, like a peaceful highway stretch, the lines between the RS5 and S5 blur, making the two seem not so different after all.

Related: Best Mods For The C7 & C7.5 Audi A6 S6

S5 Vs RS5: Is The B9 RS5 Wider?

At Canadian Auto Performance, we've noticed how the Audi RS5 really stands out from the S5, and it's not just about what's under the hood. While both cars are built on the same A5 frame, the RS5 has a few tricks up its sleeve that make it look a bit different. For starters, it's slightly wider thanks to its bigger front and back track and those cool flared arches.

The RS5 also turns heads with its special RS-style grille and a front bumper that looks like it means business. Meanwhile, the S5 keeps things more low-key, which might be perfect for those who like the idea of a "sleeper" car that's fast but doesn't show off.

What's more, the RS5 has some vents that are there for looks (along with a couple that actually do something) and comes with bigger 19-inch wheels, compared to the S5's 18-inch ones.

For anyone wanting to bring some of that RS5 flair to their A5 or S5, we've got you covered. We offer RS5 bumper conversions in three different styles and B9 RS5 honeycomb grills to give your car that aggressive edge, making it look as fierce as the RS5.

Related: What is a downpipe and why do you need to upgrade it?

S5 Vs RS5: Interior

Inside, the B9 S5 and RS5 offer a remarkably similar experience, with the primary difference being the substitution of S badges for RS badges throughout the cabin. Aside from this, the look and feel remain consistent across both models. While Audi has faced criticism in the past for skimping on luxury, it's clear that the tide has turned in recent iterations.

The RS5 elevates the standard by offering sports seats right off the bat, a feature that S5 buyers can add as an upgrade. When it comes to features and comforts, both models are well-appointed, decked out with all the luxury amenities one would expect from a high-end car.

S5 Vs RS5: What Is The Better Car To Mod?

Big shoutout to Randy on TikTok — swing by his page for some love and support. As a leading voice online for the B9 RS5 platform, he’s put together an insightful list of horsepower gains you can expect at each modification stage.

Engine	Mod Level	HP
S5 Single Turbo	Stock	349
SRS5 Twin Turbo	Stock	444
S5 Single Turbo	Stage 1	486
SRS5 Twin Turbo	Stage 1	542
S5 Single Turbo	Stage 2	510
SRS5 Twin Turbo	Stage 2	604
S5 Single Turbo	Stage 3	774
SRS5 Twin Turbo	Stage 3	770

Now, let's address a hot topic: the definition of a Stage 1 mod. This term can stir up some debate, but here's the deal: the RS5 usually outperforms until you delve into turbocharger upgrades.

The S5, being more wallet-friendly, garners more attention from aftermarket brands, leading owners to boost its performance to match or even exceed that of the RS5. With a plethora of aftermarket turbo upgrades, the S5 can go toe-to-toe with the RS5's power — something to think about, as the RS5 doesn't offer as many turbo enhancements.

If pushing the limits to Stage 3 is your goal, the S5 might just be your ticket. It’s not only a more popular choice for modders, but it also comes with a smaller price tag and has established a reputation for reliability since its 2018 release.

Read Next: Best Audis to Mod