Top Gear drives the Honda CR-Z Mugen

This Honda CR-Z is worth ‘in excess' of one hundred and fifty thousand pounds. Take a second to let that little nugget sink in, pause, and consider that this hatchback Honda CR-Z is worth more than an Aston Martin Rapide. As much as a Lamborghini Gallardo. More than twice as much as a brand-new Nissan GT-R. You might have guessed that someone had singed the edges of their credit card, what with the carbon bonnet, tanfastic orangey-bronze custom paint, forged wheels and slightly Nineties bodykit, but a hundred and fifty grand? That's enough to buy a significant portion of Barnsley, and cause most people to suspect that someone at Honda has been the unfortunate recipient of a tastectomy.

Words: Tom Ford
Photos: Paul Barshon

This feature was originally published in the August 2011 issue of Top Gear magazine

Nevertheless, that's the truth. This is no ordinary £18,375 hybrid Honda CR-Z. This is the Honda CR-Z Mugen. A one-off project to see what a hot CR-Z might look and feel like, a car capable of 50+mpg in eco mode and... somewhat less when asked to go fast. Whatever it is, it is not, definitely not, a Type R. And under that blocky deck of a rear wing and nose full of twinkly lights robbed directly from some poor soul's Christmas decorations is some serious tweakery. A remix designed to create a properly sporty hybrid, something broad-minded enough to cope with both eco and psycho. It's a hybrid for hot-hatch heads. Which is a cracking bit of alliteration, if nothing else.

So what is Mugen, and what sorcery has it wrought to make a funky-but-funless CR-Z something to put a smile on an enthusiastic driver's face? Well, Mugen is a company that has been tuning race Honda product for years. It's an entirely separate company from Honda Motor Co., but was started back in '73 by a chap called Hirotoshi Honda, son of Honda founder Soichiro Honda, and used to mainly deal in the race tuning of - you've guessed it - Hondas. In fact, amongst a roll-call of lively pep-ups for pretty much everything Honda, Mugen also supplied engines for F1 teams such as Tyrrell, Ligier, Prost and Jordan for the majority of the Nineties. It should be able to handle warming up a hybrid.

So. The science bit. The CR-Z Mugen still has the standard CR-Z's IMA electric motor, but in this version, it's been mapped to bleed into a blueprinted and internally strengthened version of the standard 1.5-litre iVTEC four-cylinder petrol, a version that now boasts a neat little centrifugal supercharger. Now, a centrifugal supercharger is all-but-identical to a turbo, but is driven directly from the engine rather than by exhaust gas. So boost increases with the square of speed, rather than the ‘always on' thump of a Rootes-type blower.

It's incredibly efficient, and kind of sits between a turbo (super-efficient, but relies on exhaust gas to get spinning) and a twin-screw/Rootes-type belt-driven supercharger (bad for efficiency and mpg but instant hit) in terms of delivery. Which means it needs just a little bit of help taking up the slack from very low rpm. Something like an electric motor in a hybrid... Handy, then, that although the CR-Z's electric motor only adds the standard 18bhp to the tally, you get that torque virtually instantly, with the supercharger filling in the usual torque hole before the revvy little petrol can step in and start swinging.

There are the usual three modes of operation: Eco, Normal and Sport (though the sport button is referred to as the ‘Mugen' button), and they affect the usual throttle maps and steering response. Mugen calls it the iCF system, which stands for Integrated Centrifugal Forced-induction, and it produces a total output of 197bhp - the standard car cranks out 122bhp - with an accompanying 158lb ft of torque (128lb ft as standard). Which is pretty much on the money for a modern hot hatch. A hot hatch like a Honda Civic Type R, just to pluck one completely randomly out of the air...

The first time you allow it to rev properly from lowdown, the CR-Z Mugen is an extremely odd experience, especially if you've ever driven a standard CR-Z. We happen to find ourselves in the middle of deepest darkest fenland the first time it happens, and the combination of a front-axle limited-slip diff (another Mugen upgrade), bumpy, subsided road and raucous delivery nearly have the CR-Z carbon-deep in a watery dyke. Torque steer, and fistfuls of it. I could blame the wider, track-spec Yokohama tyres that hum like Gregorian humpback whales on the motorway, or the rewired five-way adjustable suspension. I could blame the fact that the track on the Mugen is actually 32mm wider on the front axle than the back, and that the road we were driving on had an exceptional marbling of standing water and knobs of bone-dry tarmac. But though none of that helped, I really should blame the fact that I really wasn't paying enough attention.

It's not a baseball bat to the solar plexus. You won't have the wind knocked out of you, or your hair pulled out by the roots. But you will be a little bit startled, followed by a little bit impressed, followed by cheerfully excited by the sound of a carbon-fibre airbox doing its level best to induct the front bumper into the engine. There's silly whistling further up the rev-range, a touch of indeterminate whickering - sounded like an effeminate dump-valve to me - and the all-pervasive induction that sounds very much like a tonne-and-a-half of pea gravel being poured onto a corrugated-iron roof. It's terrific. Totally at odds with what a CR-Z usually feels like. And nearly, almost, just about seamless.

It's more than just the engine too, because the rest of the modifications help bolster the CR-Z's attitude. There's the aforementioned five-way adjustable suspension by Showa, some joyously effective 320mm brakes and a fairly comprehensive - if unimaginative - prescription of about 50kg of weight loss. The bonnet is made of carbon fibre and would sail happily away in stiff breeze like an F1-sponsored kite, and the wheels are lightweight GP motorsport items which obviously reduce unsprung mass and add a bit of feel to the front end. The doors are also made of carbon, and so light they're surprising to the touch. In fact, they're so massless that they require the windows to be open to shut them without a full palm press - otherwise the air pressure inside the car pops them half open. Tremendously amusing for half a day; less so when it's raining, and you just want to get on and the doors refuse to shut.

Once you're inside, the gentle echo reminds you that the back seats have disappeared, and the pleasing pressure on your thighs indicates that the standard front seats have also magicked themselves into slimmed-down Recaro buckets. There's a reweighted Mugen gearstick, and a triplet of extra gauges glued to the top of the central binnacle, performance car-style. It feels nicely sporty - the seats are comfortable, the seating position low enough to feel tied into the car. Once it's fired up, the sports exhaust adds a pleasant rasp at the bottom and a full-on shred at the top. In fact, the only issue with the new pipe is that the triangular finisher looks absolutely bloody ridiculous.

Which is part of the problem. You can't help feeling that this car would be a more serious prospect painted Honda ‘Championship white' like the original Integra Rs and without the Fast & Furious rear wing. The CR-Z is pretty enough to need a massage rather than a rework, and feels like an over-gilded lily. In fact, you can't buy any of the engine hardware, but you can purchase the bodykit (£2,600), gauges and gearknob (£1,600), and exhaust, wheels and suspension (£6,500). Of which I'd probably only go for the last three items, and hacksaw off the back box. But you have your own idea of taste, so we'll leave that particular point of contention there. So it's back to the idea of whether a hybrid hot hatch can really work.

The problem with assessing new technology when forewarned is that you constantly look for the point of difference. Which means that you inevitably find it. I know what's weird with the CR-Z, so I'm looking for techy stuff rather than just assessing it as a hot hatch. While I sit and ponder the problem, a faint smell of ammonia filters through the cabin, and a white Renault Clio 200 appears around a corner about 100 yards away, on three wheels.

Even though it's raining. TopGear's favourite hot hatch slithers to a stop about six inches from the deep front bumper of the Mugen, and the Stig steps from the Renault. It's raining heavily, but the water doesn't so much fall off the white humanoid as leap away terrified, and there's not a mark on his pearly whiteness, even though the lay-by is covered in a thick, glutinous layer of mud. I sigh, and vacate my seat in the Honda in favour of the Clio, popping the door just as the Mugen dials up about 4,000rpm and launches away, changing up like a stumpy golden racing car. It really does make a most amusing noise.

I follow in the Clio, marvelling at the fact that it feels like a driving position nicked from a Routemaster bus compared to the CR-Z, also realising just how compliant the suspension is on the little Honda by comparison. Where the CR-Z bucks and weaves heavily on the horrible fen roads, the Clio actually skips and bounces itself an air gap. And you have to really wind the Clio's 2.0-litre around the dial to keep up with the CR-Z. So the Mugen's a bit faster than you think.

The Stig, as ever, is on the far side of committed, and manages to load the CR-Z so hard around one corner that the tyres rub in the arches, a bright ‘BWAAAR' of noise. The Clio feels upright and lively and stiffer than I remember, and doesn't have the same amount of body roll that seems to mar the CR-Z's otherwise- hardcore line. After about an hour, I'm shattered; the fens demand so much concentration, so much absolute hanging on that the Stig is a bit of a bugger to try to keep up with. Eventually, he stops, steps out of the Mugen, gives the barest ghost of a nod, and walks away, leaving the door of the Honda open and the engine running. This is interesting. The Stig doesn't care what it looks like, he just cares what it goes like. Which means the hot hatch of the future might look like this. The fast hatch of the future could be a hybrid, dual-mode, a split personality.

But is there any point? Of course, efficiency is the new horsepower. We're entering an age where more isn't necessarily better, and getting the most out of the least is where it's at. But the RenaultSport Clio 200 we have here has near-identical power and torque figures to the Mugen (197bhp, 159lb ft), and produces 195g/km and 35-ish mpg from a traditional 2.0-litre four-cylinder engine. And it's a relatively old motor. The new VW TSI engines are producing 180bhp for just 139g/km of CO2. And driven hard, the Mugen managed just under 30mpg, pretty much the same as the Clio.

Which relegates the CR-Z Mugen into the realms of an interesting aside into hybrid evangelism. A more interesting route may have been dumping the heavy hybrid bits of the CR-Z altogether and keeping the supercharged 1.5. By my calculation, that would deliver a sub-1,000kg Honda CR-Z with a revvy little engine and a manual 'box. Driven carefully, it would be capable of decent mpg and CO2. Efficiency via the simple route, with the fun stuff tacked on the back, just like back in the day. Seems to me that to know where you're going, sometimes it pays to know where you've been.