A bolt from the blue

With diesel more expensive than petrol, can clever
technology prove that high fuel returns needn’t mean filling up from the black pump? Richard Gooding tests the Volkswagen Polo BlueGT with cylinder deactivation

Volkswagen has a long history of economical technological development. It introduced the first Golf diesel as long ago as 1976 and launched a range of economy-minded Formel E petrol models in the early 1980s. The Formel E cars featured aerodynamic modifications, high-compression engines and switchable stop-start systems. Sound familiar? The company’s BlueMotion technology was first seen on a Polo in 2008, and has since expanded to also become BlueMotion Technologies, covering a raft of economical developments. And now, once again, a Polo debuts the latest concept in the BlueMotion family.

The Polo BlueGT is hatchback that is fun to drive, yet capable of providing high fuel returns. With low emissions of 107g/km and a quoted combined cycle mpg figure of 61.4, can economy also mean fun?

PERFORMANCE AND ECONOMY
The Volkswagen Group has pioneered cylinder deactivation technology. First introduced on high-performance Audis, this clever tech has found its way into more affordable and more mainstream cars. Cars like the Volkswagen Polo BlueGT. This whole car’s raison-d’être is its engine. Armed with a 138bhp 1.4‑litre turbocharged unit with Active Cylinder Technology (ACT in Volkswagen-speak), it straddles the line between the high-performance Polo GTI and the highly economical Polo BlueMotion. It’s not just in terms of performance and high economy that the BlueGT sits between its two sisters; its starting price of £17,695 is also between the pair.

The latest Golf range also features cylinder deactivation and the premise of the technology is simple. The second and third cylinders of the four-cylinder unit are shut down and not fed fuel during low engine speeds (1,250-4,000rpm) and torque outputs of 25 to 100Nm (18 to 74lb ft). This temporary disengagement reduces fuel consumption. Similar to most stop/start systems, as soon as the driver presses the accelerator pedal once more, the two cylinders are reactivated. If that’s not impressive enough, the switchover between two- and four-cylinder modes takes between 13 to 36 milliseconds depending on engine speed. During certain instances – such as driving through heavy traffic or bursts of overtaking – the cylinder deactivation technology is deactivated for safety reasons. Due to the very little change in engine noise, the driver is notified when ACT is active by a ‘warning’ in the car’s multifunction display.

The system switchover is imperceptible. With 184lb ft (250Nm) of torque between 1,500‑3,500rpm to pull the BlueGT along, performance is brisk. Official figures quote 61.4mpg on the combined cycle, a value which is usually seen on the spec sheet of a derv-powered car. My ‘real‑world’ average was a more realistic 42.9mpg, though I did see a high a 61.4mpg, which matches Volkswagen’s official claim. During my 1,000‑mile test, figures of mid-50s mpg were easily achievable when driving with an economical mindset. And the car is capable of more. The trouble is, the cylinder shut-off doesn’t happen often enough when driving around town. However, it’s a different story when on a motorway or undertaking a relaxed long journey when the car is cruising in its mid-rev range. The ACT system cuts in and out helpfully and unnoticed.

ECO LEANINGS
As it has ‘blue’ in its name, the Polo BlueGT also has further Volkswagen BlueMotion Technology concessions to economy.

A stop/start system, battery regeneration, gear change indicator, cruise control and lowered suspension are all part of the Polo BlueGT’s make-up. The BlueGT’s eco leanings are also helped by a marrying of styling touches from both Polo GTI and BlueMotion models. The GTI donates its and aerodynamic rear spoiler, while the side skirts, windscreen rain channels and lowered suspension are cribbed from the BlueMotion. Blue ‘GT’ badging and 17-inch alloy wheels complete the look. A tyre pressure indicator and multifunction fuel consumption display further aid economic driving.

With economy only 10 to 20 per cent down on a diesel-powered supermini, the BlueGT sums may just add up. Petrol is currently cheaper than diesel, while its BIK is the same as the lower‑emission Polo BlueMotion, yet there’s more performance on offer. A high specification is also standard. On the road the ride is firmer than lesser Polos but still compliant and the car feels more agile than its lower-powered siblings.

With green priorities shifting, petrol engines which return high mpg figures are on the rise. VW states that ‘BlueMotion’ badging denotes the cleanest, most energy-efficient cars in its range. With the Polo BlueGT, it shows that the pursuit of economy and low emissions needn’t be the preserve of a diesel engine or a dull experience. It also ably demonstrates that you may just be able to have your green-flavoured cake and eat it

VW Polo BlueGT

ENGINE: 1395cc, 4-cyl petrol
CO2: 107g/km
MPG (combined): 61.4
VED: Band B, £0 first year,
£20 thereafter
BIK: 13%
PRICE (OTR): £18,315 (incl VAT, £18,925 as tested)