Does anyone have knowledge on the subject? My Thema engine feels much more responsive on a dry -5C winter day compared to a hot summer afternoon, so the physics of cooling air to reduce it's size really seem to work

And actually while I am at it : Does anyone know the if/what the difference is from the 2L Thema turbo and Delta turbo engines?? (185 HP 8V & 205 HP 16V)
Regards,Thomas