Piston mphete ndi mphete yachitsulo yomwe idayikidwa mu piston poyambira. Pali mitundu iwiri ya pisitoni: kuphatikizika mphete ndi mphete ya mafuta. Nnenete yosokoneza imatha kugwiritsidwa ntchito kusindikiza osakaniza mu chipinda cha oyaka. Mphete yamafuta imagwiritsidwa ntchito popukutira mafuta owonjezera kuchokera pa silinda.
Piston mphete ndi mtundu wa mphete yachitsulo yotupa yokhala ndi kuphatikizika kwakukulu kwakunja. Amasonkhanitsidwa ku ma porror anch ofanana ndi mbiri. Kubwezeretsanso mphete za piston kumadalira kusiyana pakati pa mpweya kapena madzi kuti apange chidindo pakati pa mphete yakunja ndi sing'anga ndi mbali imodzi ya mphete ndi poyambira.
Mphete ya piston ndiye gawo la injini zamafuta. Imasindikiza mpweya wamafuta pamodzi ndi silinda, piston ndi khoma la cylinder. Ma injini wamba omwe amagwiritsidwa ntchito amakhala ndi injini ziwiri za dizilo, chifukwa cha kuchuluka kwa mafuta ndiosiyana, koma ndikusintha kwa pisitoni, monga kupopera kwa matebulo, ectional, ganyu Nitring, mawonekedwe akuthupi, zokutira pansi, zojambula za Bosphase, zincsese, mphete ya piston imathandizidwa kwambiri
