What is it?
With car manufacturers seeking ever cleverer ways to reduce the consumption of their latest models to meet stringent emission standards we've been exposed to quite a lot of new fuel saving technologies n recent times.
Features such as automatic stop/start, brake energy recuperation, on-demand engine ancillaries and low rolling resistance tyres have gone from being exotic options not that long ago to just about universal standard today.
However, they're not the end of it. Because, as signs have it, there's another fuel saving technology that's about to go prime time: cylinder shutdown, or as Volkswagen prefers to refer to it, Active Cylinder Management (ACM), for small displacement engines.
Previewed by Volkswagen earlier this year, it is included on a frugal new version of the German car maker's latest turbocharged 1.4-litre four-cylinder direct injection petrol engine, the EA211 as it is known, fitted to a new sporting version of the Polo called the BlueGT.
The principle of ACM is simple, and a good deal less expensive than other systems already applied to larger capacity powerplants, with a set of electronic actuators sitting above the camshaft on the middle two cylinders controlling the movement of the valves and fuel injection.
At revs between 1400 and 4000rpm and torque loads between 18 and 74lb ft - a characteristic Volkswagen claims covers nearly 70 per cent of all driving states, the valves and injection process is shut down, effectively turning the engine into a 700cm3 twin for lower consumption and emissions, most noteably in city driving and at constant motorway speeds.
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I think VW should offer the 105bhp 1.6 turbodiesel engine in the Polo in the UK - it's available in the identical Ibiza, Fabia and A1. The downside to this engine is that it usually comes with a five-speed 'box, which makes motorway journeys not as refined and frugal as they could be. Nonetheless, it can emit 99g/km of CO2 in heavier cars, like the Golf and Octavia, so should manage about 80mpg in the Polo. It would also offer decent performance and loads of torque.
Fidji5 wrote: I think VW
I am always a little puzzled about this pre-occupation with the number of ratios in a gearbox. For motorway work it is the final drive ratio that matters. If the power unit has adequate torque and refinement then a four speed actually would be adequate. I have no experience of the 105bhp power unit mentioned but there are several instances where press reviewers are unimpressed by its noise and refinement levels. Six, seven or eight forward ratios would not alter this.
Gears!
Doesn't it spread the ratios so that the power is used better with 6 gears? Why are car makers putting 6 gears in now? Iwould agree about motorway driving but around town I find it much better to have a wider spread of ratios. It's not as though they're go-faster stripes or even these rediculous low profile tyres many are obsessed with. Regards. quote=Flatus senex]
I am always a little puzzled about this pre-occupation with the number of ratios in a gearbox. For motorway work it is the final drive ratio that matters. If the power unit has adequate torque and refinement then a four speed actually would be adequate. I have no experience of the 105bhp power unit mentioned but there are several instances where press reviewers are unimpressed by its noise and refinement levels. Six, seven or eight forward ratios would not alter this.
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[quote=petegeoff] Doesn't it
[quote=petegeoff]
Doesn't it spread the ratios so that the power is used better with 6 gears? Why are car makers putting 6 gears in now? Iwould agree about motorway driving but around town I find it much better to have a wider spread of ratios. It's not as though they're go-faster stripes or even these rediculous low profile tyres many are obsessed with. Regards. quote=Flatus senex]
I actually equate gearboxes sprouting extra ratios as being akin to low profile tyres and go faster stripes as fashion whims. (As an aside I bought a vehicle as a "no brainer" offer which included both but got the garage to remove the go-faster" stripes to the considerable benefit of its appearance!) Perhaps these questionable three or two cylinder power units do need an extra ratio or two but, assuming a motor with a decent spread of torque, the first four speeds deal with all urban situations. From 35mph upwards top gear is selected and any further stirring of the gear lever (which has a fuel consumption penalty in itself) is rarely needed.
Who knows?
Flatus senex. I agree about numbers of gears some autos seem to have now. 7 and 8 seems a lot. Not driven any like like that yet. Can the car make up its mind which gear to be in? Especially at low to medium speeds. I can't see car makers going back to 5 speed manuals now though.
On another point, "fake" gears on CVT 'boxes. Any point to that? I'm sure I've seen some ads saying a car has x number of gears on a CVT ! Regards.
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Isn't this engine 1390cc, not 1395cc?
I'll be very much surprised
I'll be very much surprised if it hits that 62.7mpg figure in the real world. Given how well "massaged" cars are to go through EC mpg testing, I wouldn't be surprised if it falls to mid 40s realistically.
Plus, I'm unconvinced by what message this car is giving. Is it sporty with economy, or an economy car made to look sporty? Think I'd sooner have the old 1.9 GT TDI Polo.