Lawula isivinini senjini
Ukufundwa kwe-tachometer kutshela umshayeli ukuthi ushayela ngendlela eyongayo nokuthi angakwazi yini ukuyidlula ngokuphepha imoto enensayo.
Izinjini zezimoto zisebenza ngesivinini esibanzi kakhulu - ukusuka kokungenzi lutho ukuya esivinini esikhulu. Ukusabalala phakathi kokuguquguquka okuncane nokuphezulu kuvame ukuba izinkulungwane ezingama-5-6. Mayelana nalokhu, kunezindawo ezihlukahlukene okufanele kube lula ukuze umshayeli azibone. 
Kunobubanzi bejubane lokongayo lapho ukusetshenziswa kukaphethiloli kuphansi kakhulu, kukhona isivinini injini ekhiqiza ngaso amandla amaningi, futhi ekugcineni, kukhona umkhawulo ongeke weqiwe. Umshayeli, oshayela imoto ngokuqaphela, kufanele azi la manani futhi awasebenzise ngenkuthalo, ngokwesibonelo, ukwandisa ukusetshenziswa kukaphethiloli.
Ukufundwa kwe-tachometer kutshela umshayeli ukuthi injini isebenza kuluphi uhla, ukuthi sishayela ngendlela eyongayo nokuthi singakwazi yini ukuyidlula ngokuphepha imoto ehamba kancane.
