Mercedes-Benz Gls450 vs Audi S1

What's the difference?

The GLS450d impresses as an entry-level grade, as it’s a more family-friendly allrounder than the specialised AMG and Maybach variants. Its combination of a torque-rich diesel 48V hybrid drivetrain, air-cushioned suspension and plush interior are as well suited to luxury urban travel as they are to grand touring, where its heavy towing and generous load-carrying capabilities can shine. Whether it’s worth around $200K drive-away, only those who shop at the top end of town can decide.

Cars this small shouldn't be this fast and useable at the same time, but the Audi S1 is. It isn't without its problems - the ride is harder even than the Fiesta ST which might weary some prospective buyers.

It's also a bit difficult to justify the price - in its basic form it's missing a few creature comforts that you'd expect in a $50,000 car - reversing camera, high-res screen, that sort of thing.

However, in the hot hatch world, those things don't matter. It has the bragging rights, the tech and the outright blinding speed to take on the bonkers Focus ST and equally zany Megane RS. And even the Audi S3.

This is an imposing vehicle in extravagant S-Class tradition, riding on an expansive 3135mm wheelbase and stretching more than 5.2 metres (5215mm) long and more than 2.0 metres (2030mm) wide with a turning circle that's nudging 13 metres.

However, it’s just under 1.8 metres (1798mm) tall, so there’s no clearance issues when accessing multi-storey carparks. And with its side-steps (or ‘running boards’ in nostalgic Benz speak) most adults can step rather than climb aboard, although passengers of shorter stature during our test noted that assist handles on the A and B pillars would be handy.

Central to its sophisticated chassis design is adaptive air suspension, which uses a pneumatic or ‘airbag’ form of springing with adaptive damping to continuously optimise ride comfort and handling response according to road conditions and driving dynamics (see Driving).

The GLS’s styling is clean and uncluttered with tasteful restraint evident in its chrome and satin-chrome highlights, yet it projects a majestic quality with its prominent four-louvre grille and elegantly spoked alloy wheels.

The spacious and sumptuous seven-seat interior is visually pleasing and practical, with a subtle blend of surface treatments, contrasting tones, lots of soft-touch surfaces and exposed stitching. This is combined (thankfully) with physical dials, switches and ‘piano key’ buttons to control numerous interior functions, in preference to distracting touchscreen prompts.

The A1 is so small it starts to strain Audi's design language. When you cram on the S-style bumpers and raccoon-eyed trim on the hatchback, it's starts to look a bit busy.

It isn't quite a shrink-wrapped A3 - Ingolstadt's designers know better than that - but it's full of Audi design cues, such as the strong, light-catching character lines, distinctive LED daytime running lights and fondness for big wheels.

Inside is along the themes of the A3, with what are becoming Audi's trademark; round eyeball air-con vents, the manual fold-down screen familiar to Q3 owners (but smaller) and a good clear dash. The handbrake jars slightly as it feels cheap to hold and wobbles a bit.

The S Sport seats are big and comfortable, and the top half of the backs are capped in plastic, which was colour-coded on our car. The rear passengers will certainly get an eyeful of whatever terrifying hue you've chosen, so choose wisely.

Despite the five doors, the back seats are occasionals, like the Mini the A1 is gunning for, and the boot is very small, but okay for shopping for couples or singles.

Starting at $49,900, Audi S1 is by far the priciest of the small-hatch based hotties, at least until Mini's madcap JCW arrives. This price is just almost double that of VW stablemate's forthcoming 2015 Polo GTI.

Standard on the manual-and-five-door-only S1 is a ten speaker stereo, climate control, ambient lighting, remote central locking, cruise control, satnav, headlight washers, auto headlights with xenon low beams, partial leather seats, leather-bound steering wheel, auto wipers and rear parking sensors.

Our Misano Red ($990 option) came with two extra packs. The Quattro Exterior Package ($3990) adds bi-xenon headlights with red trim, red brake calipers, spoiler, quattro logos on rear doors (ahem!) and five-spoke 18-inch alloys that are part matt black, part polished.

The Quattro Interior Package ($2490) adds S Sport front seats with Nappa leather and red backrest capping with quattro logo (ugh), more nappa around the cabin with contrast stitching, flat bottom steering wheel and red rings on the air vents.

There's an S Performance Package that brings the best of these two packs together for $4990, saving about $1500 and the embarrassment of the quattro logos.

Our test car also had aluminium air vents ($220), black contrasting boot lid ($300) and black roof ($720).

The A1 is so small it starts to strain Audi's design language

The grand total is a sobering $58,610. There's a couple more options that'll easily pop you over $60,000.

Audi's MMI is dash-mounted in the A1 as there's no room on the narrow centre console. As ever, it works well and doesn't take much getting used to. The satnav is a bit grainy on the smaller screen but is otherwise a competent unit.

Sound is from a ten-speaker stereo and you can stream across Bluetooth or plug in a memory card. The sound was good but the system did take a while to find the phone whenever we came back to the car.

The GLS450d comes standard with a 3.0-litre turbocharged inline six-cylinder diesel producing 270kW of power at 4000rpm and 750Nm of torque between 1350-2800rpm.

This is paired with a 48V mild-hybrid system comprising a 48-volt battery (charged by regenerative braking) and an integrated starter-generator which provides both seamless engine stop-start and up to 15kW/200Nm of extra power and torque during acceleration.

A nine-speed torque converter automatic provides the choice of manual shifting using the steering wheel-mounted paddles, along with several selectable drive modes.

The active all-wheel-drive system continuously adjusts the engine’s torque delivery between front and rear axles (and individual wheels as needed) to maintain optimum traction and handling.

This is where the action is. The S1's tiny body packs a 2.0-litre turbocharged four-cylinder producing 170kW and 370Nm of torque. The S1 will streak to 100km/h in 5.9 seconds thank to the traction aid of quattro all-wheel drive.

All Audi S1s come with a six-speed manual

Despite a pretty solid hammering during its week with us, including more time than we'd have liked in Sydney traffic, the stop-start function helped deliver a pretty reasonable 10.2L/100km, however that's a long way over claimed 7.1L/100km.

All Audi S1s come with a six-speed manual, so dual-clutch haters can save the whining. The only downside from not having a self-shifter is the ECU can't deliver the boy racer farts, parps and crackles of the other S cars.

It’s an enjoyable vehicle to drive, with multiple power adjustments for the seat and steering wheel combined with a large left footrest which provide supreme driver comfort and support.

The powerful and responsive turbocharged six-cylinder diesel and nine-speed auto are well suited to this application. The engine’s ample torque provides spirited acceleration from standing starts, taking only six seconds to reach triple-digit speeds.

This drivetrain would be well suited to heavy towing duties, given the 48V mild-hybrid system can contribute an extra 200Nm (in addition to the engine’s 750Nm), which raises the total theoretical torque output to almost 1000Nm.

The active air suspension provides a wonderfully cushioned ride that floats over bumpy roads, while maintaining excellent handling response and surprising agility. These commendable chassis dynamics, combined with the powerful and responsive drivetrain, makes the vehicle feel smaller and lighter than its dimensions and kerb weight would suggest.

Overall, it’s difficult to fault from a driver’s perspective, with the only exception being the voice activation function. This is often triggered by words or phrases other than ‘Hey Mercedes’ resulting in regular interruption of conversations. This needs some fine tuning.

If you're buying the S1 as a comfortable urban runabout with a cool badge, you're half right. While the seating for front passengers is certainly supportive, the hard suspension tune will ensure you're well aware of road surface imperfections.

The S1 is a rocket

Thankfully, what it missed out on in the ride department it makes up for in every other way - the S1 is a rocket. The 2.0-litre turbo jammed under the bonnet has almost no lag and is paired with a slick six-speed manual that is terrific fun to manhandle through the gears.

The way the S1 picks up speed when it's on boost is addictive and licence-endangering. A flattened accelerator in second or third will obliterate just about anything this side of $100,000 and you'll be having more fun in this than big brother S3 because the chassis is more adjustable and there's a bit more life.

You can hear the turbo sing to accompany the bassy exhaust growl. Hit the massive brakes hard and the car remains stable even over rutted roads. Turning the wheel brings almost-instant turn-in, mashing the throttle again a fun little wriggle. It's superb.

It's tremendous fun point-to-point on a twisty road

You'll have to be a bit patient with the throttle to get the wriggle, though - give it too much too early and it will want to push wide, the quattro system shuffling power around to try and quell understeer while the electronic diff fiddles with the braking system to do the same thing. It gets there in the end, but you're better off meting out the power with your right foot for maximum rewards.

It's tremendous fun point-to-point on a twisty road - despite being a bit heavy for its size (1415kg), it's as chuckable as the next best thing, the Fiesta ST.

Six airbags, stability and traction control, ABS, brake assist and distribution all add up to a five star ANCAP rating.