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Citroën boosts efficiency of DS5 hybrids; as low as 91 g CO2/km

Citroën has augmented the efficiency of its DS5 hybrid models. All three Hybrid4 200 Airdream EGS6 models in the DS5 range have received technical updates to deliver CO2 emissions from 91 g/km with improved fuel economy.

New management software has been developed for the full-hybrid diesel powertrain with a number of technical improvements to optimise DS5’s efficiency. Key enhancements include improved energy recovery when decelerating and braking, and a new battery management system.

The newly re-homologated DS5 Hybrid4 drivetrain reduces the official CO2 emissions for the DSign model from 99 g/km to 91 g/km. DStyle and DSport versions see their emissions reduce from 107 g/km to 102 g/km.

17-inch alloy wheels are available as a no-cost option on Hybrid4 DStyle and DSport versions. These smaller diameter alloy wheels reduce the cars’ CO2 emissions from 102 g/km to 91 g/km— the same as the entry-level DSign.



This is impressive, but how can a smaller diameter alloy reduce Co2 emissions from 102 to 91 gms ?
That is a huge amount - can there be that much rolling resistance in the larger tires ?

And if so, why can't this be done (or offered) to all vehicles?


Low profile tires end up having much more rotating inertia (bad), wasting fuel in stop and go driving. Maybe they also have more drag with a more squared shoulder.

Look at top level race cars, none have very low profile tires.


Low profile tires generally wear faster and have more rolling resistance.

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