I've noticed 3 different versions of Michelin's Energy tyre. Can you tell me what the differences are?

Question from Scenic, 28/12/2010 :I've noticed 3 different versions of Michelin's Energy tyre. Can you tell me what the differences are?MICHELIN Energy Saver
MICHELIN Energy E3A
MICHELIN Energy Saver S1
Answer by rezulteo, 28/12/2010 :

The Energy Saver represents the evolution of the Energy E3A further improving energy efficiency while preserving the balance of benefits in terms of grip and durability.

The S1 version has preceded the introduction on the market as original equipment of Peugeot 308.