▁Trans it ' s ▁first ▁two ▁dies el ▁electric ▁hy brid ▁bus es ▁went ▁into ▁service ▁in ▁December ▁ 2 0 0 6 . ▁The ▁unique ▁design ▁and ▁colour ▁scheme ▁of ▁the ▁two ▁Or ion ▁low ▁floor ▁bus es ▁have ▁been ▁chosen ▁to ▁enable ▁them ▁to ▁' stand ▁out ' ▁from ▁the ▁rest ▁of ▁the ▁E TS ▁fleet . ▁The ▁bus es ▁were ▁part ▁of ▁an ▁extensive ▁test ▁of ▁hy brid ▁technology ▁that ▁Ed mont on ▁Trans it ▁and ▁the ▁University ▁of ▁Al berta ▁ ▁conducted ▁over ▁a ▁year . ▁Bus ▁reli ability , ▁performance , ▁maintenance ▁costs , ▁fuel ▁efficiency , ▁noise ▁generation ▁and ▁environmental ▁impact ▁were ▁monitor ed ▁and ▁evaluated ▁in ▁all ▁weather ▁and ▁road ▁conditions . ▁As ▁well , ▁customers ▁were ▁survey ed ▁about ▁their ▁travel ▁experience . ▁Ult imately , ▁the ▁Hy brid ▁bus es ▁only ▁recorded ▁fuel ▁sav ings ▁of ▁ 1 0 - 2 0 % ▁( in ▁contrast ▁to ▁the ▁ 3 5 % ▁tout ed ▁in ▁the ▁internal ▁ad s ). ▁In ▁ ▁addition , ▁the ▁I SE - New ▁Fly er ▁hy br ids ▁( 6 0 0 3 ▁and ▁ 6 0 0 4 ) ▁were ▁out ▁of ▁service ▁so ▁much ▁that ▁they ▁could ▁not ▁be ▁included ▁in ▁the ▁evaluation . ▁ ▁As ▁of ▁fall ▁ 2 0 0 9 , ▁only ▁the ▁two ▁Or ion ▁hy br ids ▁are ▁in ▁service . ▁ ▁New ▁Fly er / I SE ▁hy br ids ▁ 6 0 0 3 ▁and ▁ 6 0 0