Since coding in a new parking aid module, using SDD, I notice that my indicated average MPG which used to be 28 is now 15 - 21 max. Range is estimated at 420 miles on a full tank.
It is a pre DPF 2008 HSE auto. Can SDD have messed up the readout? If so, how do I correct it?

I also noticed this after an SDD coding session.
I'm pretty sure it's down to the adaptives being reset.
Mine went back up to mid 30s after a few weeks. Hyundai Ioniq 5 Ultimate. The family car.
2009 Rimini Red SE TD4. Gone.
2006 Tonga Green i6 HSE. Gone.
Audi A5 convertible, my daily driver.
1972 Hillman Avenger GT, the project.