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Mercedes-AMG GTR vs Porsche 911 GT3 comparison feature

By Ryan Lewis | Photos: Nathan Jacobs, 18 May 2019 Features

Mercedes-AMG GTR vs Porsche 911 GT3 comparison feature

Mercedes-AMG GT R and Porsche 911 GT3 touring: divergent evolution and an ode to finding your joy

IT’S GETTING harder to be a car enthusiast by the day. Soaring levels of congestion, declining levels of courtesy, rising fuel prices, ever more oppressive enforcement of regulations, punitive car taxes and a negative public image are constantly working against us. It’s no wonder getting a driver’s licence is no longer an automatic choice for many young people.

But in the right car, on the right road, there’s something about driving that’s a special kind of therapy. What constitutes the ultimate driver’s car is the subject for pub banter to keep groups of car nerds out all night. But there is no question that every great driver’s car should compel its owner to do one thing: grab the keys and drive.

For a lot of people, the Porsche 911 is the consummate driver’s car. Its evergreen appeal is owed in large part to a set of fundamental ingredients that remain unchanged even after decades of development. It’s the yardstick by which other sports cars are measured, and in the guise we have here, its purity is arguably at its most distilled.

Late in 2017, Porsche became particularly displeased with market speculators flipping limited edition 911 Rs at a profit. One take on the GT3 Touring option pack is that it’s Porsche having the last laugh, by giving buyers of new GT3s a 911 R-alike package without the mark-up.

Behind the rear axle sits an awe-inspiring 368kW/460Nm 4.0-litre naturally aspirated flat-six and the same six-speed manual as in the 911 R. But the Touring pack deletes the GT3’s roll cage, harnesses, and – most notably – rear wing. In Carrara White over satin aluminium centre-lock wheels, it might be the most beautiful 911 money can buy.

Beautiful is not a word you’d choose to describe its flamboyant challenger. The Mercedes-AMG GT R is rude. In Jupiter Red – surely the best colour available – it’s a retina-grabbing showstopper oozing supercar presence.

No other iteration of AMG’s second, clean-sheet sports car is more powerful. Its 4.0-litre twin-turbo V8 wrecking ball produces 430kW and 700Nm, with maximum torque delivered across a broad 3600rpm span starting from just 1900rpm. It is the antithesis to the peaky, rev-hungry GT3, bundled into a performance chassis with race-derived active aerodynamics.

The GT R looks especially spectacular from the rear. Its broad wing lines up perfectly with the turret, and a trio of exhaust outlets sit within an enormous diffuser inspired by GT3 racers. Side-by-side with the pared-back 911, it’s strange to think these cars come from the same city.

As tested, the prices of these two are separated by just $6199. The GT R is more expensive at $372,129, but their base prices are drastically different. The Porsche is some $24,000 cheaper there, but nobody is buying a GT3 Touring without adding options, and it’s all too easy to rack up a significant bill with only light box-ticking. Our GT R, on the other hand, is relatively standard. Carbon-ceramic stoppers ($17,500) and forged wheels ($3500) are the only items added.

Fixed-back bucket seats are a no-cost option, though they’re canted back a little further than those in the Porsche and don’t quite provide the perfect driving position. Chunky shoulder bolstering also gets in the way of the GT R’s awkwardly positioned shifter, which is wedged way back in the transmission tunnel where only stumpy T-Rex arms can get at it.

Some packaging compromises are dictated by the proportions of the AMG’s monstrous drivetrain. The GT R is a V8 skateboard with a cabin shrink-wrapped to the top of it. There’s limited space inside around the tree-sized centre console that hides a torque tube for the seven-speed transaxle. Anything tucked into the tiny cubby near the back gets warmed to serving temperature.

Conversely, the GT3 is an ergonomic masterpiece inside. It guides the driver’s hands to inadvertently rest in the ideal driving position on a perfectly sized steering wheel. Porsche’s engineers simply have this mastered. No other cabin is as finely honed, and a connection forms before the car turns a wheel.

The GT R takes a little more acclimatisation. Gazing down the long hood it feels deceptively large, when it is in fact shorter than a C-Class, but sitting near the rear axle and telegraphing steering commands to the remote front-end is initially disconcerting, especially when things get moving as quickly as they do.

The AMG’s appetite for tarmac is utterly ferocious. With enough traction, three digit speeds are dialled up in mere moments. The official claim for a perfect launch is 0-100km/h in 3.6sec, but once into its stride the GT R is even more impressive. Clever electronic systems precisely judge available grip before feeding in everything it has on tap. Hooked up and hammering, the GT R is a runaway train of colossal Teutonic brawn that feels as though it could slide out from beneath you.

The Porsche’s engine has an entirely different character. Given its racing pedigree and top-end performance focus, its flexibility is remarkable. The 4.0-litre pulls cleanly from low revs and charges forcefully towards redline, building intensity with each gearshift. In a straight-line sprint the GT3 is slightly slower to three figures at a claimed 3.9sec, but its superior grip often leaves the GT R looking flummoxed.

Power and torque ramp with engine speed to peaks much higher in the rev range than the GT R’s. Maximum twist arrives at 6000rpm, full power hits at 8250rpm, and getting there is an utter thrill, with the shrieking flat-six seemingly mounted to the driver’s spine. It fizzes through a twilight zone between 7000 and 9000rpm like an overclocked dentist’s drill that won’t stop spinning. Nailing a perfectly timed upshift as the needle reaches the frenzied limit of its arc is among the sweetest feelings a driver can experience.

Everything about the GT3 is geared to get to nine grand, and that has an immediate effect on the way you drive it. Distances between corners become a game of mental processing power; with the goal to reach redline with enough room left to pin the brakes and clip the apex before launching at the next one.

Acoustics hard-wired into the cabin dictate the GT3 experience just as much as the outright speed. A baritone note vibrates the cabin furniture at idle, then morphs, with more revs, into a deep bellow that hardens at 4000rpm and picks up yet more volume. There’s an intoxicating level of detail in the GT3’s soundtrack that never gets old.

The AMG’s aural accompaniment is a cacophony of an entirely different spectrum. How anybody could live with the whirr of an electric car after hearing either of these two is beyond me. The GT R snarls like lions baying for blood, especially when launching from a standstill using its Race Start function. But it’s much more than a straight-line weapon.

Pushing through turns the GT R’s front-end grip is phenomenal. It sticks with unwavering commitment, assisted by a four-wheel-steering system that adds low-speed agility and high-speed stability. With familiarity the GT R seems to shrink and become easier to place, and the initial remoteness of its steering rack melts away. From lock-to-lock the AMG’s steering is quicker and lighter than the Porsche’s, yet feels more artificial in its assistance; as do the brakes, though their stopping power is huge.

The GT R is a marked step above a regular GT S, with a surprisingly broad and approachable performance window. Barrel it into a corner at whatever speed and it has the tools to sort it out on the fly.

Competent electronic aids make it a doddle to slide around, too. The Porsche is much less willing to cut lurid shapes, and asks to be driven quite differently. It demands intelligence and anticipation from the driver to deliver its best results. Power understeer is there to greet those who aren’t set up before a corner and patient with the throttle. Get it right, though, and the 911’s traction on corner exit is incredible.

The GT3 relies on precision inputs, which makes the driver somehow more integral. That often means accepting that you are the bottleneck in its performance envelope, but the rewards are on another level. It has a mechanical immediacy and authenticity that is fully engrossing.

At 100km/h on a fast backroad the mood inside each of these cars is entirely different. The GT R feels totally unstressed lapping up corner after corner with minimal exertion. That it has acceptable ride comfort is a huge surprise given the stiffness of other AMG GT variants. There’s a cruising talent to this GT that its track-focused appearance doesn’t immediately suggest.

Conversely, the highly strung GT3 is always standing to attention and bubbling with an energy that can’t be dialled back. It’s a bit of a confused thing, this GT3 Touring. Some rough and ready characteristics are expected from the regular, be-winged race car with numberplates. But its brake squeal, drivetrain shunt and ride stiffness don’t fit with the Touring part of its name. Calling it that implies a softness – a touring ability – that it just doesn’t have. But that doesn’t make it any less brilliant as a driver’s car.

A greater level of tactility and connectedness is what the Porsche ultimately has working in its favour over the AMG. There are some easily quantified advantages too, not least of which is their relative fuel use. The GT3 wasn’t exactly a miser at 15.9L/100km over our test, but the GT R needed 20.6L/100km. And you could practically hear it guzzling in the wetness of its exhaust note; as though forearm-sized fuel lines were hosing the combustion chambers with 98 RON.

The GT R’s ability to deliver a heavyweight blow is the quality that makes it a thoroughly compelling proposition. It somehow feels stronger, a little bit more pliant, and as though it has more in reserve. A degree of sensitivity and feedback is still to be found by AMG’s engineers, but what they have developed is a much more complete package than its hot-rod theatrics might have you think. For some, it will be the better choice, with a demeanour that’s easier to live with and a more casual approach to going ridiculously fast. The Porsche is completely undiluted by comparison. It seems to run on a knife edge, and ultimately delivers the sharper, more alert driving experience.

That pure, mechanical sweetness instils in the GT3 Touring a final level of involvement and satisfaction that makes it the most accomplished in the art of driving for its own sake.