Infiniti M35h review (2011 onwards)

What - Infiniti M35h
Where - Silverstone, UK
Date - August 2011
Price - £46,840
Available - Now
Key rivals -BMW 535d, Mercedes E350 CDI, Lexus GS450h
Summary - High-tech hybrid ensures the currently unique Infiniti M35h is a very intelligent, very able green performance choice.

We like - Super-sophisticated hybrid system, real-world 40mpg potential, styling, quality, cabin
We don't like - Dynamics lack the shine of the drivetrain, boot space, can Infiniti communicate the broad hybrid benefits to potential buyers?

Gallery: Infiniti M35h
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First impressions

Infiniti's green credentials have gone from red-faced to good as gold. At launch, all it could offer were thirsty, Euro-unfriendly V6 petrol engines. Today, it offers its newest car, the M saloon, with diesel AND hybrid engine options - making it the only brand on sale in the UK to do so.

Audi, BMW and Mercedes all talk about it, but none can yet offer a hybrid exec saloon here. Infiniti's system is a very advanced one too, designed by parent company Nissan and set to feature in many of the firm's hybrid products. It's a generation on from systems found in current Lexus, for example.

Key to it is two-clutch technology, which allows the electric motor to drive the seven-speed gearbox, and also allows the engine to be disconnected from the drivetrain completely. This gives much more flexibility in on-road situations than more restrictive current-generation hybrid systems.

Why go hybrid instead of diesel? For the zero-emissions engine-off ability, a drive enhanced with an EV-style torque boost at low speed, the ability of intelligent driving to realise very impressive real-world economy gains... and because some people still don't 'like' diesel. Few make petrol engines as smooth as the Japanese, and it's a key part of the M35h's appeal.

The M35h is as shapely as all other Ms. This is a modern, curvaceous executive saloon, more organic than Germanic. Think smooth, broad sweeps of calligraphy, says Infiniti: evidenced in the pronounced wheelarches, the rounded coupé-style windowline, the gentle shoulder flowing smoothly front to rear.

It lacks the visual clout of most other British Ms though, because it only comes in GT trim: S brings 20-inch alloys and other beefy sport-focused enhancements, but the hybrid is currently unavailable in this BMW M Sport-style upgrade. Infiniti is, we're told, working on it...

Performance

Swift performance is delivered in a satisfying, sophisticated way, not least because it uses a proper seven-speed automatic gearbox, rather than an irritating CVT. The highlight is, if you're gentle, a broad range of electric-only running. At city speeds, it's remarkable how far you can travel without the engine cutting in.

You'll barely notice when it does too, for the 3.7-litre V6 is extremely well isolated in low-demand situations. Thanks to the electric motor's high torque, pressure is off the engine to roar when sharp acceleration or standing start getaways are needed: electricity does the hard work.

What's even more amazing is how the engine regularly switches off on the move. Infiniti has intentionally designed the hybrid drivetrain so that the engine decouples whenever possible (when lifting off the accelerator, for example), with the electric part supplying drive for as long as it can.

One result of this was an extended 50mph run through a motorway roadworks zone in engine-off, zero-emissions mode. The only reason the engine started up was because the batteries were depleted, but even this range was extended by energy regeneration. This ability is what makes the Infiniti hybrid unique.

In decidedly non-hybrid mode, the engine roars and growls like a sports car. It's a very charismatic V6 when worked (it's the same as in the Nissan 370Z, after all) and, at higher revs, a rapid and lively one, too. It feels impressively strong and powerful at high revs.

The blend of hybrid and petrol engine modes is seamless and managed by a smooth-shifting automatic (with fast-response electronic clutch rather than soggy torque convertor). The only oddity we found was a tendency to 'run on', when the engine started up and we lifted off shortly after (say, town duck-and-dive situations). It happened a couple of times, proving that an otherwise impressive hybrid set-up isn't quite perfect.

Ride and handling

Infiniti doesn't have a drive USP yet: for BMW, it's handling, Mercedes' is ride and Jaguar's is delicacy. The M35h suggests Infiniti wants a bit of all three, with some Audi-style lightness to aid ease of use too.

It initially has a sporty feel to it, with a firm edge to the ride. However, at speed, there is an impressive long-suspension-travel absorbency that's able to tackle a broad range of road conditions. It's thus a reassuring and soothing long-distance cruiser.

A large car, it at first feels cumbersome. Nudging the light steering generates quite a bit of suspension reaction. With time though, it proves to be a precise steer, short on sensations but with good basic balance and accuracy. It's satisfying without shouting about it.

What we really liked was its ability to awaken when we switched from green to sporty mode. The rear-drive layout allows you to bring the back end into play around bends, balancing it with the throttle and exploiting the engine's high-rev vim (enhanced, of course, by the electric motor torque). For all its eco credentials, it's this slight rawness that we're pleased Infiniti has also retained.

Interior

Infiniti makes lovely, lovely interiors. As its newest car, the M is the best in the range. It's packed with (that word again) organic shapes, curves and flowing lines, with some complex yet natural 3D shapes that sets it apart from other executives. It's a treat to use; a very pleasant place to be.

Naturally, it's of excellent quality. The materials are almost a match for Audi and the precision build they show is, with its millimetric panel gaps and super-tight feel, maybe even better than the German standard-setter. It's rich in a way a BMW 5 Series and Mercedes E-Class can't quite match (and equipment is unbeatable too).

Passengers sit up high: this is a car with a tall stance and commanding feel. The wide centre console adds to the effect, and shorter passengers will find themselves stretching to close the door when it's open: that's how wide it is. This carries through to the rear, where there's decent space and, again, ample comfort.

The sticking point is the boot. Those batteries have to live somewhere: they do so in the space behind the rear seat, dropping the boot size down from 500 to 350 litres. Still, as Infiniti points out, it's still wide and deep enough to take a couple of sets of golf clubs...

Economy and safety

With standard safety equipment including auto-brake collision avoidance and distance-keeping cruise control the M35h is certainly safe. But it's economy that you're really interested in, so here's the score: officially, the M35h averages 40.4mpg (better even than the diesel) and emits 162g/km CO2 (sadly missing that vital 160g/km barrier).

We tested it over nearly 1,000 miles, and found (according to the trip computer) these figures are realistic, too. Hybrid doesn't always deliver, but this does - what's more, if you drive with your eco brain, you can stretch this further, too.

After one motorway run, we checked the trip computer: 41.5mpg. Remarkable - particularly as it didn't drop when we hit city centre traffic, either. Normally, economy readouts worsen in town but, thanks to the engine-off abilities of hybrid, that wasn't the case here.

It wasn't a one-off, either. Another relaxed run saw us score 42.6mpg on the readout. And, the next day, we didn't reset it but drove the 120-mile return journey considerably less ecologically minded. Result? 41.5mpg again. This is real world economy, fully proven: the Infiniti M35h hybrid works as a green performance saloon.

The MSN Cars verdict

The M35h is a good car and a superb hybrid. The advanced drivetrain means it is a hybrid that works in real-world driving, rather than in a science lab, and the free-running sophistication it brings is very satisfying. It looks good too, and the cabin is a real treat.

In other ways, the M35h is merely good, but the on-road intelligence it offers will really appeal to the thinking driver, who will find a lot of reward from driving it. With eye-opening economy there for the taking, the M35h is worth a test. Just make sure it's an extended one - there's a lot to take in...

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