What is it?
This may look like a humble, if rather stylish hatchback, but there’s more to the Mazda 3 Skyactiv-X than meets the eye. Look under its bonnet and you’ll see, well, an awful lot of plastic actually. That’s because its 2.0-litre four-cylinder petrol engine is enclosed in a ‘capsule’ to promote a faster warm-up that improves efficiency.
But that’s just the tip of the iceberg, the really clever stuff involves what Mazda calls SPCCI or spark controlled compression ignition. Under light loads, a very lean fuel and air mixture is pushed into the cylinder under a diesel-like 16.3:1 compression ratio on the intake stroke. As the piston squishes everything, a small amount of a richer mixture is squirted near to the spark plug. Igniting this instantly raises pressure so the leaner mixture also ignites, burning cleaner and more efficiently. However, put your foot down and it operates like a regular petrol engine, at least, that’s the theory.
To further improve efficiency, there’s also a 24v mild hybrid system that uses a combined starter/generator to harvest energy when you’re slowing down. This can then be used to assist the engine when accelerating from a standstill, for instance. The end result is 178bhp without the use of a turbo, emissions from just 100g/km and official fuel economy of 51.4mpg. That’s rather impressive.
Join the debate
jason_recliner
1,486 kg!
Takeitslowly
jason_recliner wrote:
A tad pricey too...typo...it is to be hoped.
LP in Brighton
Figures don't add up
Unfortunately the official fuel consupmption of 51.4mpg (5.5 l/100km) does not tally with C02 emissions of "from just 100 g/km". Burning 1 litre of petrol should release around 2392g of CO2, so by my arithmetic, the actual CO2 figure should be 132 g/km.
I'm not blaming Mazda for this discrepancy, but I assume that it results from manufacturers being allowed to quote fuel consumption from one test (WLTP) but use a different one (NEDC correlated) for CO2 values.
Nevertheless, it is impressive that Mazda have put this engine into production - and even Autocar's quoted 48.7 mpg figure isn't bad a family hatch with a 180 horsepower petrol engine.
For the final proof though, it would be good to see just how the Mazda compares with its competitors under identical driving conditions.
xxxx
Family car?
It doesn't ride well, rear passengers will suffer from claustrophobia, you need rev it which (coupled with it's weight) explains why this mild hybrid uses so much fuel and it'll be expensive. Nah
michael knight
Dead-end.
Mazda are sometimes to be admired but i reckon they're heading down a cul-de-sac here.
1500kg?
Torque-peak 3K rpm
125g/km (amazed that just by spec this changes by 25g/km)
48mpg
In something that weighs 1200kg this might make sense both for improved efficiency and performance, but as it is it appears to be a compromise from the perspective of both with this car weighing what it does, i don't get it.
Will86
Supercharger?
No mention of the engine using a supercharger, a fairly critical detail Autocar. As for the engine itself, I feel a bit underwhelmed. It doesn't sound like it an especially interesting engine to use even if the technology behind it is unique and the economy figures are fairly unremarkable. Part of the appeal of Mazda's rightsizing approach is its simplicity and effectiveness, but this adds a whole host of extra complexity for not a great deal of gain. It would be really interesting if Autocar could do a detailed real world economy test between the Skyactiv-G, Skyactiv-X and the diesel.
xxxx
Supercharger?
I did think that but I can only presume with so little power and torque it didn't make it into this version.
Marv
It does include a supercharger...
... it's not there to increase power, but to provide enough air to allow the engine to work correctly in 'compression' mode and at lower revs.In regards to real world figures, I'm sure they'll come once the engine is officially on sale.
Based on estimates currently available, I suppose the comparrisons look as follows;
BHP - 2.0G: 118, 2.0X: 178, 1.8D: 118
KG/KM - 2.0 G: 119, 2.0X 100, 1.8D: 107
MPG Combined - 2.0G: 44.8, 2.0X: 51.4, 1.8D: 56.5
0-62mph (secs) - 2.0G: 10.4, 2.0X: 8.2, 1.8D: 10.3
The figures look even better compared to the 2.0G [165] and 2.2D [185] from the 6.
I'm as Mazda always do, they'll improve and further perfect this tech, and I for one am looking forward to seeing how much of a benefit it is in real-world use. At present, I think it provides a pretty interesting and useful half-way house between a petrol and diesel, which I believe is what they had set out to do.
Sorry, boring afternoon in the office.
xxxx
So compression ignition, supercharger, mild hybrid
It kinda of does improve power and it's delivery, but, at the end of the day those items:
Makes it more expensive
More to go wrong and service
Heavier
48mpg nothing special from a mild hybrid
180hp and little torque low down from a 2.0 supercharged mild hybrid engine is poor.
jason_recliner
xxxx wrote:
What do you mean?
It isn't particularly expensive, if it gets 50ish mpg in the real world that's pretty good for a mid size car, and 8.2 seconds is competitive. Being a Mazda, it's unlikely to break down often or be especially pricey to service.
How it drives, feels and performs is surely more important than whether it is or is not 'competitive' against some subjective on paper standards for a given feature set.
Pages
Add your comment