The differences are the amount or the concentration of oils that are in the scents. The higher the concentration of oils, the longer your scent will last, and the less you should need to apply. Are all of your products genuine?.
DUNHILL LONDON DESIRE BLUE FOR MEN 100ML EDT SPRAY BRAND NEW & SEALED
Alfred Dunhill Century Blue Eau de Parfum 135ml Spray For Him - NEW. Men's EDP
Dunhill London Icon Racing Red Eau de Parfum 100ml Spray For Him New
DUNHILL LONDON Desire Red Eau de Toilette 150ml EDT Spray Authentic - New Sealed
DUNHILL LONDON FOR MEN 100ML EAU DE TOILETTE SPRAY BRAND NEW & SEALED