Ford Mustang Boss v BMW M3 v Audi RS5 v Mercedes C63 AMG

Here’s today’s premise: Imagine you are part of the US Air Force based in the UK (I rather think I’d be called Hank) and you enjoy driving. What do you choose to make your journeys between bases? Loyalty dictates that you should pick the new, all-American Boss 302 Mustang. But can it really cope with the narrow, bumpy and, above all, twisting roads that interlock middle England? Wouldn’t you instead be better off accepting defeat, swallowing your national pride and picking a German V8 with some independent rear suspension…?

The particular part of middle England where we find ourselves today is littered with ex-USAF bases. Two of them, Thurleigh (otherwise known as the Bedford Autodrome) and Bruntingthorpe, we visit regularly – and will do again during the course of this test. But for the first day we are going to be driving between three other airfields: Molesworth and Alconbury, which are still in use by our American friends and therefore off limits, and Upwood, which closed down a few years ago and which we hope we just might be able to access.

Together this triumvirate make up the so-called ‘Tri-Base Area’ and there are some fantastic roads criss-crossing the land between them (including the legendary B660), so if the latest version of the Mustang can handle this novel commute, it could just be a success this side of the pond.

The day begins with the Mustang, Audi RS5, BMW M3 and a new Mercedes C63 Coupe all parked outside the imposing Cold War-spec security fencing at RAF Molesworth (stations retain their RAF signature despite having baseball pitches rather than cricket wickets within their grounds). The sky overhead is nearly as forbidding as the barbed wire and it’s not long before the first heavy raindrops begin to fall.

The familiar bulges and stances of the two white cars still look good and everyone seems to like the more rakish lines of the C63 Coupe, but there is really only one car in this quartet that people are going to stop and gawp at when its stationary. The big orange ’Stang with its blanked-off lights would make some supercars seem like shrinking violets. And the attitude of the jutting front splitter could have been stolen straight from the chin of some impossibly macho comic-strip hero. The Ford is massive too – look at the labels in their collars and even the big Audi would only be wearing XL to the Boss’s XXXL.

Photographer Gus Gregory hasn’t been wielding his Hasselblad for long before, unsurprisingly, a couple of pickups rumble towards us and two USAF policemen get out. They’re perfectly friendly but one of them has a very large assault rifle and wants us to clear off. So, despite being tempted to strike up a discussion about our two countries’ ‘special relationship’, we saddle up and roll out across the rapidly moistening Cambridgeshire countryside.

It’s fairly safe to say that we’ve been unlucky with the conditions. A day either side and we would have been enjoying perfect combine harvesting weather, but today we’ve got rain, and because it’s the first for a while that means the roads are slicker than a beach in the Gulf of Mexico. It’s a pain for the photos, but in some ways it’s actually quite instructive for assessing the cars. A good, well-balanced and communicative chassis should shine through, while any handling foibles will be exacerbated…

The M3 has to be the favourite in this test – it’s not for nothing that Ford decided to target the BMW by cheekily fitting this Mustang with a number plate beginning ‘M3’. However, with 414bhp and 295lb ft, the BMW has the least power and torque of any of the cars here. It’s also the oldest, something you notice most clearly as you look around the unremittingly black dash. Trickling through the aptly named village of Old Weston, the seat also seems higher than I remember and the steering wheel still feels unnecessarily chunkily rimmed.

All of this is forgotten as soon as you press the small ‘M’ button to tune the throttle, dampers and DSC just so and simply concentrate on driving. The M3 doesn’t feel like a coupe, it feels like a sports car, such is the tautness of its chassis. Direction changes happen with an alacrity and force that you really wouldn’t expect of something with four seats and a boot, while the tight, slightly metallic howl from the 4-litre V8 speaks of tiny tolerances and a motorsport mentality. Our test car is equipped with BMW’s Dual Clutch Transmission, and although we’re big fans of the knuckly manual shift, there’s no denying that the small silver paddles attached to the back of the wheel allow you to make the absolute most of the sweet, high-revs powerband. The ratios (there are seven) feel slightly shorter than they do in the manual too, so you really seem to be able to sprint between corners and there’s a fantastic zip to the blips on downchanges.

Our journey from Molesworth to Alconbury takes us along a brilliant road that is narrow yet fast because it is largely very well sighted. The M3 invokes curious feelings when you drive it quickly in the wet. It inspires confidence because it generates a huge amount of grip and there’s a very positive edge to lean on when you’re cornering, but at the same time it sows a little seed of nervousness, because you’re always wondering if, once the phenomenal grip runs out, the drop-off in stiction will be alarmingly instant and possibly final.

You can be almost certain that when the grip does run out it will be behind you, because the nose seems to be nailed to the road no matter what. This means you can concentrate on exactly how much power to feed through the M-diff to the tyres, and that’s made easier by the fact that there is absolutely no wooliness to the accelerator – it’s like drinking chilled neat gin to most cars’ warm Merlot.

You have to lean hard on the Michelins to get them to relinquish their hold on the road and they let go in a flash once they do, but the steering is so quick and the accelerator remains such a precise instrument that the M3 is definitely a car to be enjoyed over the limit. As long as you’re alert you can bleed out of the throttle rather than jumping off it entirely, thus keeping the wheels spinning sweetly for almost as long as you want.

RAF Alconbury’s runway might be chock-a-block with stationary lorries rather than active aircraft now, but there is still a model Northrop F5-E Tiger II (yes, I looked it up) outside the gates and, amazingly, the sun comes out briefly as we pass by. Keen not to chat to any more bristling USAF police, we don’t stop for long and just swap cars before heading on towards the excellent B-roads on the far side of the airfield.

The Audi RS5 is undoubtedly the best car of our foursome to sit in. The big, wing-backed buckets are instantly sportier than the BMW’s slightly plump chairs, with less padding and more support. The high transmission tunnel accentuates the feeling of sitting lower in the chassis too, and the rest of the interior gives the usual Audi impression of being inside a beautifully elegant B&O stereo.

Unfortunately, while it’s a lovely thing in which to listen to Test Match Special as the rain begins trickling down the windscreen once more, things aren’t so good when you start driving the RS5. The steering is the first surprise – it just feels so light and unconnected. On the kind of wide, smooth roads that really ought to suit the big coupe and its four-wheel drive, it feels utterly vague, and the front end appears to have a worrying lack of grip. A fiddle with the various chassis, steering, sport-diff and transmission settings improves things a little, but you have to leave the suspension in Comfort, otherwise it’s needlessly harsh with apparently no travel at all.

The 444bhp Audi is certainly quick down the straights, and the 4.2-litre V8 is a match for the M division V8. But trying to negotiate corners neatly at any speed is more nerve-wracking than balancing the BMW on a knife-edge of oversteer. The front tyres seem to relinquish grip earlier than expected – the onset of which isn’t really communicated – and then you’re left with a rather inert lump sliding across the surface of the tarmac. Not nice.

Gus, shooting from through the sunroof of his venerable Subaru Forester, is now starting to resemble a trawler captain on the bridge as he battles against the elements, but others are not so hardy and I have to turf sub editor Ian Eveleigh and friend of evo Phil Holland out of the Mercedes, where they’ve apparently been ‘assessing the radio’.

The C63 has been the eternal bridesmaid to the M3 in the past, but then it was always saloon versus coupe, whereas now the Mercedes comes in two-door guise as well. It might just be my imagination, but it does seem like you’re sitting lower in the Coupe when you get in and feel the excellent seats gently squeeze your abdomen. Alcantara also greets your hands when you grip the flat-bottomed and topped wheel, while the metal paddles feel decently weighty (and cool if you’ve had the air-con pointing at them).

Twist the key and you’re treated to a single deep, almost impatient growl firing from the exhausts, like Selma and Patty, the chain-smoking aunts from The Simpsons, simultaneously clearing their throats. It’s the best-sounding engine in this test, Detroit V8 included.

With 451bhp and 442lb ft, the C63 also feels the fastest of the cars here, with a wonderfully torque-rich delivery that gives you that intoxicating light-limbed feeling under sustained acceleration. The seven-speed auto is one of the better Mercedes gearboxes, but using the paddles in manual mode can still seem a ponderous process compared with the rapid-fire BMW ’box. In fact, I discovered recently that the best way to treat an AMG cog-shuffler is to put it in Sport+ and leave the paddles alone. It might feel a bit weird relying on the car to do all the work, but there’s also a curious delight to hearing the car change down two or three gears at the last moment as you brake hard for a corner – it’s a bit like one of those confidence games where you have to close your eyes and trust someone to catch you as you fall backwards.

The C63 Coupe’s new suspension settings definitely make it a little tauter than the saloon (although that’s due to get the settings too), with the whole chassis working and responding as one, yet it still has a wonderfully easy demeanour. You feel encouraged to throw it around and really work the rear tyres. Set the ESP to Sport Handling mode and it’s surprising and gratifying to find that you can get the tail a long way out of line before the safety net catches you. Even if you pack up the nanny’s bags and take her to the bus station, the Merc still feels incredibly friendly over the limit. You can be gratuitously greedy with the throttle, light up the tyres halfway through a corner and hang the boot into the breeze and it never feels unsettled. And because the steering is quick but beautifully judged, you don’t even need to take your hands off the wheel to gather it up.

With the cornering shots in the bag (on a closed piece of road but a rather unnervingly fast corner) we all swap cars again and head towards our last USAF haunt – RAF Upwood. There’s a decision to make before you even start the Boss’s engine: which key are you going to start it with? The normal key has a grey badge, but there is also a red-badged ‘TracKey’. Twist this in the ignition barrel and the engine mapping configures itself to the full Boss 302R race-car set-up, complete with fantastically lumpy idle. Although you don’t actually get any more power, low-end torque is improved and throttle response is sharpened.

Even without the TracKey’s race mapping, the Boss engine is significantly modified over a standard Mustang GT’s 5-litre V8, with a new intake and new camshafts helping lift power from 412bhp to 444bhp, although curiously the torque drops by 10lb ft to 380lb ft. It’s the only car in the test with a manual gearbox and it’s a really good one, with the pool ball-topped gearlever sitting perfectly in the palm of your hand and movement around the gate feeling tight and precise. The picture is completed by perfectly placed and nicely responsive pedals for heel-and-toeing.

As an aside, it’s perhaps worth mentioning where ‘Boss’ came from. Famous designer Larry Shinoda had just been recruited from GM by Ford President Bunkie Knudsen (himself a former GM exec) when he started work on the original 1969 Boss 302. The car was intended to dominate SCCA Trans-Am racing and the whole project was highly secret, so when asked what he was working on, Shinoda would reply ‘the Boss’s car’. The rest, as they say, is history.

To be honest, the Mustang still feels a bit too much like a throwback to that original car. Despite new adjustable dampers there is still a lot of roll in the set-up that robs it of any comparable precision. The big, Alcantara-trimmed wheel feels great and you can hustle the Mustang surprisingly quickly and amusingly down a narrow road, but it is a process of sometimes worryingly big gestures. The suspension is 11mm lower at the front but only 1mm lower at the rear compared with a standard GT and it feels like it, with the back taking an age to rock onto its springs and start really working the tyres after you’ve turned in. The more positive and almost aggressive your inputs the better, as this keeps things loaded up, but it feels like a big car to try and control… particularly when there are also bumps and cambers constantly distracting it from your hoped-for trajectory.

Amusingly, the Mustang’s radio describes Radio 4 as ‘Adult Hits’ and Classic FM as ‘Nostalgia’ (which might be understandable if you were born in Austria in the eighteenth century). Nostalgia is certainly something that’s dripping from the remains of RAF Upwood when we get there. Under a leaden sky it’s an eerie, post-apocalyptic sort of place to wander around, and the lack of people in a place so clearly designed to be inhabited makes the hairs stand up on the back of your neck. I suppose Bruntingthorpe and Bedford were like it at one point…

The Drag Race

They’re all about as quick as each other, that’s what it boils down to! With joint best 0-60mph and 0-100mph times, the M3 is the quickest if you go by the figures in the table, but it takes an absolutely perfect launch (which is very hard to achieve) to get those numbers – more frequently it would be at least half a second slower to 60mph.

Supreme traction from quattro helps the big Audi reach 30mph before anything else, but its launch control isn’t happy with more than a couple of attempts and, curiously, it is the slowest car from 60 to 100mph.

The C63 AMG has a Race Start mode, but it still struggles to put all of its 451bhp down off the line. From there onwards, however, it absolutely flies and is also the most consistent car.

Finally, the Mustang. With the TracKey inserted, you can choose to hold the revs wherever you want for the launch control, which is quite clever, but like the Mercedes it still struggles not to smoke its tyres off the line. However, it is joint fastest (with the AMG) from 60 to 100mph and its times are very impressive when you consider that you have to change gear manually and all the others have automated transmissions.

Circuit Shootout

There are plenty of things to like about the Boss Mustang but, as we’ve discovered, on the road it can’t compete with the broad breadth of high-tech thrills deployed by the scalpel-sharp M3 or the hot rod-esque C63 AMG. So what about on track? Here that lack of sophistication may not be such a compromise; a composed chassis and a decent slug of grunt can be both entertaining and very fast without gizmos. Indeed, Ford claims that the Boss is faster than an M3 around the Laguna Seca circuit in California.

Will the same hold true at the Bedford Autodrome here in the UK? The Mustang will certainly have to be exceptionally good to scalp the BMW. Select the stiffest suspension setting, switch out the stability control completely and the M3 takes on the attitude of a race car. The front end lasers-in on apexes, the throttle can be picked up early, the balance is spot-on, and the very clever M-Diff gets all of the power onto the tarmac. The brakes are powerful (for a while at least – the pedal begins to go soft after three hard laps) and the M DCT gearbox not only ensures your hands can remain on the wheel, but wastes no time slicing through the seven ratios.

You need quick wits and reactions to keep on top of the M3 – it will break away hard and fast, particularly through the high-speed corners, but you can ride the limit as it’s clearly detailed through both seat and wheel. A fast lap is a thrilling buzz of speed and efficiency and the lap time of 1.25.1 is properly rapid. The perfect weather (20 degrees and not a breath of wind) probably explain why this is the fastest lap we’ve ever scored for an M3. And Ford reckons its 302 is even faster…

I insert the red ‘TracKey’ into the barrel, fire up the rumbling V8 and head out again. The 5-litre has a broad spread of power and, encouragingly, the throttle response is as crisp and clean as the M3’s. There’s a manual gearshift to be operated, of course. In fact, although it’ll be impossible to match the Bavarian hardware on every shift, the Boss’s shift is precise, feelsome and effective.

The early signs are good, then. Trouble is, things take a turn for the worse as we get near the bendy bits. The brakes have meat, but not the sharpness of response of the M3’s. More of an issue is the way the Boss pitches forwards, suggesting a considerably softer spring set-up than is ideal on track. It’s amplified on turn-in – the precision that was key to the M3’s success isn’t there with the Mustang and it also requires more steering lock, labouring the whole cornering process.

What it needs to stay in the game is high levels of grip and traction, but it lacks these too. Through mid-speed turns the rear tyres have trouble matching the fronts, slipping into oversteer where the M3 would be hanging on. The Ford is also too vague in terms of feedback; it feels a world away from being a true M3 rival and the stopwatch confirms it: four seconds off the pace.

Neither the Audi nor the Merc can quite catch the BMW either, the RS5 proving stonkingly fast but efficient rather than fun, the C63 hilariously lairy but just a little too tail-happy. But has the M3 done enough to win the group test outright?The Verdict

So, should Hank or any other airman really choose a Boss 302 over its European competition? Well, it takes the scalp of the RS5. We’ve said it before, but I’ll say it again: it’s nothing to do with the four-wheel-drive Audi’s inability to oversteer. The steering simply lacks any consistent weight or feel and the ride and handling seem to lack any subtlety or poise. As nice as I’m sure it would be to spend a long time in on an Autobahn, it’s no fun over here.

The Mustang is next to fall. It looks abso-flippin’-lutely fantastic and I’m sure there are some people for whom that will be enough. We loved the lumpy tickover with the TracKey, the gearbox is great and there’s even some satisfaction to be had wrestling it at speed between the hedges and ditches of various shire roads. However, character can only go so far and in all honesty ‘the Boss’s car’ is still dynamically some way behind our leading pair…

Choosing between the M3 and the C63 is incredibly difficult, and if you are lucky enough to be in the market for either one I couldn’t fault your decision whichever you plumped for. But there has to be a winner, and it’s still the BMW. The decision is easiest to make when jumping from the M3 back into the C63, because it’s then that you really notice how everything feels slightly softer and less focused in the Mercedes. Some might prefer this as an everyday experience, but the extra weight and feedback of the M-car’s steering, the lack of slack, its fantastically sharp throttle and super-precise chassis mean it is still the best drivers’ car. Whichever side of the Atlantic you’re on.