Throughout the eighties and early ninties it was common for the drag factor of car to be published in both the car promo books and WHAT CAR? used to have all the drag factors in there. Even van's have had their drag factors shown.
I recall at that time the worst being the Citroen 2CV6 at 0.56 and Mini Mk1 0.48, the best Vauxhall Calibra 2.0i (not 16v) 0.26. Vauxhall Carlton 0.28.
The Mk2 Astra was 0.32 on all hatchbacks except the belmont and Estate which I think was 0.34&5 and the GTE which was 0.30.
Does anyone know the drag factors of the all the models of the Mk1-5? Is there a database somewhere on the net?
I would like to add that since the mid 1980's drag factors have not come down, if anything they have stayed the same or increased in some cases!