O͘-iû (烏油) ia̍h-sī ki-iû (機油) sī choan-bûn iōng tī-leh lōe-jiân-ki ê jūn-ku̍t-iû. O͘-iû tû-liáu ē-ēng jūn-ku̍t, iáu-ū chheng-kiat, chó͘-chí seⁿ-sian kap léng-khiok ê kong-lêng. Chit-má sú-iōng ê o͘-iû ê ki-chho͘ iōng-iû sī kēng, chū-hi-kēng (PAO) kap chū-lōe-hi-kēng (PIO) téng sêng-hūn lâi cho͘-sêng, lóng-chóng sī iû thoàⁿ kap kheng só͘ cho͘-sêng ê iú-ki hòa-ha̍p-bu̍t. Ū chi̍t-kóa khah-ko-kip ê o͘-iû tiong ē pau-hâm 20% í-hā ê chi-lūi.

Chē-chē khoán ê o͘-iû