I have now covered >800 miles with this set of Bridgestone Turanza 6 on my MG4 SE SR to replace the Continental PremiumContact C that came as original equipment.
TL;DR
The Turanza 6 return the same combined energy consumption as the OE PremiumContact C on the MG4 SE SR in size 215/50R17, but do so with vastly improved and consistent handling in all conditions, especially on wet and cold surfaces
Noise
Noise: the Turanza 6 are louder; they emit what I can only describe as brown noise, a low pitch woosh, especially on wet surfaces or rough tarmac. The noise is not a rumble, and does not annoy me in the slightest, it is just more noticeable at speeds above 30 mph. The wind noise coming from the right wing mirror is much louder and still audible, so these tyres are definitely on the quiet end of the scale.
Handling
Consistent and predictable: turn in is sharper, but not dramatically so. The sidewalls are compliant and the ride quality is better than the OE tyres: much fewer vibrations but improved feel.
They excel in the wet, providing plenty of grip. Their nature suits the rear-wheel-drive configuration of the MG4: the backend loads well under acceleration during corner exit at speeds between 30 and 50mph, which is fast sweeping bends on country lanes.
In the dry, the tyre is very sticky even on cold tarmac, and behaves like any regular summer tyre, despite the lower rolling resistance.
More importantly, the Turanza 6 feels safe and surefooted in mixed conditions: transitions between wet and dry, even mid corner, do not upset its stance and changes of direction are swift and precise.
Energy consumption
There's definitely some improvement in energy efficiency, up to 0.2 miles/kWh more on the wet, especially when temperatures are low or at higher motorway speeds. The increased traction is very noticeable under breaking, especially with higher regen levels.
In the dry, at lower speeds, such as around town, the OE tyres were possibly more energy efficient, but at speeds above 50 mph there was no difference in consumption, yet a more sure footed ride, 70mph on the Turanza 6 feeling like 60 mph on the OE tyres.
A combined winter/summer average consumption will probably be either about the same, or 0.1 to 0.2 miles/kWh better depending on your driving style and weather conditions.