It makes no sense, but it’s effective, appealing and fun

What is it?

Technically, it’s Mazda’s first model to be offered with a fuel-saving, emissions-lowering stop-start system. But, for reasons we’ll get on to, it’s easier to think of this car as a lukewarm version of the Japanese car maker’s facelifted 3 hatchback, which just happens to have some new and interesting engine technology.

As anyone who’s checked out this car’s vital statistics will have already observed, this car might have commendable fuel economy and emissions for a 148bhp petrol-powered five-door, but it’s no rival to Ford’s Focus Econetic on either fuel economy or CO2 emissions.

Mazda has been developing its own engine idle stop-start system for some time. It’s different from other systems because it doesn’t include a conventional starter-generator. Instead, Mazda’s system restarts the engine after a brief halt in traffic using a slightly more sophisticated and more powerful starter motor and Mazda’s own ‘DISI’ direct injection system.

The system automatically stops the engine when it detects the time is right and, once stopped, it automatically aligns the engine’s pistons towards the middle of their stroke. Using crankshaft position sensors it detects which piston is on a power stroke and, the instant you hit the clutch to move away again, it simply injects fuel into the cylinder, ignites the mixture, and uses the starter motor to put enough kinetic energy back into the crank to get it spinning again.

Mazda says its system is faster to restart and creates less vibration than a conventional starter-generator. But it does only work on direct injection engines...

Given that it had already added direct injection to the 3 MPS’s 2.3-litre turbo motor, and allowing for the fact that it simply wants to roll out DISI and i-Stop technology throughout its petrol engine range as quickly as possible, the easiest first step for Mazda was to add direct injection to the related 2.0-litre before it adapted it for the smaller 1.6-litre petrol four. Eventually it will adapt the system to work with its diesel engines too, but there are hurdles to overcome when dealing with compression ignition.

So forget about whether you think this should be Mazda’s launch car for its emissions-saving stop-start system; for nowat least, this 2.0-litre 159g/km 41.5mpg Mazda 3 is the only ‘i-Stop’ model that the company could offer. Phew. Moving swiftly on…

What’s it like?

Quite an impressive and much-improved family hatchback. The last 3 was an odd, unfinished and unsatisfactory car in many ways; this new one’s got more pleasing and less anonymous exterior styling, and a much softer-touch and more upmarket cabin. It’s both more refined and more enjoyable to drive too.

The old 3’s unsettled and noisy ride has gone, replaced by near Golf-like rolling refinement and handling that’s supple and compliant as well as sporting. Its power steering is also better than it used to be, although could still offer more natural feel.

What’s improved most is this car’s dynamic repertoire. The way it corners, and rides bumps and dips in the road, is much more confidence-inspiring than the old 3; this is a car you can engage with, even lean on occasionally. It feels like bosom kin of the benchmark-setting Ford Focus, while the old one seemed a very distant relative indeed.

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Mazda’s excellent new direct-injection 2.0-litre engine plays its part in this car’s success. Torquey from low revs yet willing to work hard beyond 5000rpm, it provides just enough power to give this car entertainment value, but never is it harsh or slow to respond.

Although 32mpg was as near to Mazda’s official economy claim of 41.5mpg as we could get this car to return on a mixed test route, the stop-start system worked effectively too. It was hard to perceive any speed or refinement advantage over a conventional system, but the way it elected to leave the engine running when stopped on inclines, or with the wheels turned away from the straight-ahead at junctions, seemed particularly clever.

Should I buy one?

If you like the idea of a fun-to-drive petrol-powered family hatch that won’t cost so much to keep, quite possibly. Proper hot hatches are more fun; proper economy cars go further on a gallon. But while you’d have thought the two concepts irreconcilable, Mazda has somehow succeeded in bringing them together with this car.

The Japanese brand has produced something genuinely interesting and different here; a low-CO2 special with bucket seats, 17in alloys, a sports exhaust and a large rear spoiler. It makes no sense, but it’s effective, appealing and fun nonetheless.

Matt Saunders

Matt Saunders Autocar
Title: Road test editor

As Autocar’s chief car tester and reviewer, it’s Matt’s job to ensure the quality, objectivity, relevance and rigour of the entirety of Autocar’s reviews output, as well contributing a great many detailed road tests, group tests and drive reviews himself.

Matt has been an Autocar staffer since the autumn of 2003, and has been lucky enough to work alongside some of the magazine’s best-known writers and contributors over that time. He served as staff writer, features editor, assistant editor and digital editor, before joining the road test desk in 2011.

Since then he’s driven, measured, lap-timed, figured, and reported on cars as varied as the Bugatti Veyron, Rolls-Royce PhantomTesla RoadsterAriel Hipercar, Tata Nano, McLaren SennaRenault Twizy and Toyota Mirai. Among his wider personal highlights of the job have been covering Sebastien Loeb’s record-breaking run at Pikes Peak in 2013; doing 190mph on derestricted German autobahn in a Brabus Rocket; and driving McLaren’s legendary ‘XP5’ F1 prototype. His own car is a trusty Mazda CX-5.

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Add a comment…
nsd 12 October 2009

Re: Mazda 3 2.0 Sport i-stop

I've been interested in Mazda's iStop system since the start of 2009, but personally I'm not ready to consider it further until it's at least available on the 1.6 litre model - hurry up Mazda! A 2 litre engine is good as a showcase, but not competitive in the green sector. Mazda are loosing ground.

Also, all the info I've read about the car to date fails to mention anything about regenerative braking technology. I presume this means this feature is absent, so I'm interested to know why. Perhaps, since iStop does not place as heavy demands on the battery as other start-stop systems, Mazda feel this is uneccessary? I don't know, but if I do decide to buy a green car from new in the next year or so, I'll want it to be still desirable in the 2nd hand market when I sell it in years to come. Therefore its good to know what's missing as well as what is present, and why.

aceman 11 July 2009

Re: Mazda 3 2.0 Sport i-stop

artill wrote:
Is that what we call warm now. i hope thats just plain wrong.

I'm with you on that - it can't seriously be classed as sport verison - 10s is pretty slow

Uncle Mellow 1 July 2009

Re: Mazda 3 2.0 Sport i-stop

Lanciaman wrote:
That`ll be fun when it goes wrong!

That'll be in about 2029 then.