The other energy savings is gained by flexing less inner tube mass. The tire and tube are deformed as they roll over the ground. This deformation takes energy. By reducing the thickness of the tube, the energy needed to roll the wheel over the ground is reduced. More of the rider's energy is used to propel the bike forward at a higher speed.
Torelli tubes are butyl rubber.
Extensive investigation and tests convinced us that the reliability and repairability coupled with the low cost made butyl the only choice. Many riders live in areas where thorns and stickers are a problem. For them, using an ultralight tube is usually impractical. At the request of many riders in Arizona, the Torelli ATB tube is available with a schraeder valve, allowing the insertion of a small amount of tube sealant. The riders tell us that they still end up with a net lighter tube, and they also have a reasonable amount of flat protection.