2 s ▁were ▁built , ▁Rock well ▁offered ▁an ▁option ▁for ▁increased ▁fuel ▁capacity ▁( 6 8 ▁US ▁gall on ▁vs . ▁ 4 8 ▁gall on ▁standard ▁t anks ). ▁ ▁The ▁ 1 9 7 6 ▁Commander ▁line ▁introduced ▁two ▁new ▁models , ▁the ▁Commander ▁ 1 1 2 TC ▁with ▁a ▁tur bo charg ed ▁engine ▁of ▁ 2 1 0   hp ▁and ▁M TO W ▁of ▁ 2 , 8 5 0   lb , ▁and ▁the ▁Commander ▁ 1 1 4 ▁with ▁a ▁six - cy l inder ▁Ly coming ▁IO - 5 4 0 ▁engine ▁of ▁ 2 6 0   hp . ▁The ▁ 1 1 2 TC ▁had ▁a ▁significantly ▁improved ▁cru ise ▁speed ▁of ▁ ▁when ▁flying ▁at ▁higher ▁alt itudes , ▁as ▁high ▁as ▁, ▁which ▁was ▁a ided ▁by ▁a ▁ ▁increase ▁in ▁wings pan . ▁However , ▁the ▁low ▁clim b ▁performance ▁made ▁this ▁useful ▁only ▁on ▁long ▁tri ps ▁where ▁the ▁clim b ▁time ▁was ▁not ▁a ▁serious ▁issue . ▁In ▁comparison , ▁the ▁ 1 1 4 ▁offered ▁a ▁far ▁better ▁power plant ▁for ▁the ▁air frame , ▁providing ▁roughly ▁the ▁same ▁cru ise ▁speed ▁as ▁the ▁ 1 1 2 TC ▁but ▁at ▁lower ▁alt itudes , ▁and ▁the ▁extra ▁power ▁giving ▁it ▁far ▁better ▁clim b ▁performance . ▁ ▁In ▁ 1 9 7 7 ▁the ▁wing ▁span ▁stretch ▁of ▁the ▁T C ▁model ▁was ▁applied ▁to ▁the ▁base ▁ 1 1 2 ▁to ▁produce ▁the