倾斜的?    oblique (tilt)

成角度的    oblique(tilt)

暗度刻度?    obscuration scale

倍频程?    octave

臭味?    odor

越野车?    off-road vehicle

偏置?    offset

偏心曲柄连杆机构?    offset connecting rod

油浴式空气滤清器?    oil bath air cleaner

集油器?    oil collector

机油消耗量?    oil consumption

油环?    oil control ring

机油散热器?    oil cooler

放油口?    oil drain hole

油道?    oil duct

机油滤清器?    oil filter

加机油孔?    oil filter cap

油底壳?    oil pan

机油减压器?    oil pressure relief valve

机油泵?    oil pump

机油泵出油管?    oil pump outlet pipe

抛油圈?    oil slander

机油滤网?    oil strainer

照明车    oil well cracking acid pumping truck

灌注车?    oil well cracking acid pumping truck

油冷式发动机?    oil-cooled engine

井架运输车    oil-well testing vehicle

油田试井车?    oil-well testing vehicle

车载摄像机?    on-board camera

单缸熄火试验?    one cylinder shut off test

整体式凸轮轴?    one-piece camshaft

整体式曲轴?    one-piece crankshaft

单座小客车?    one-seater

油压挺杆?    ooil tappet

全流式烟度计    opacimeter

烟度计?    opacimeter

不透光度?    opacity (lgiht obscuration

烟度计    opacity of exhaust gas

排气烟度?    opacity of exhaust gas

开式燃烧室?    open combustion chamber

开式喷嘴?    open nozzle

缸体宽度（转子机）?    operating width