- SM
-
An API designation of engine oil that provides improved oxidation resistance, improved deposit protection, better wear protection, and better low-temperature performance over the life of the oil than previous designated oils. Some SM oils may also meet the latest ILSAC specification and/or qualify as Energy Conserving. It replaces API Service Category SJ and SL.
API SM category
- Small-block engine
- During the '60s and '70s, GM, Ford, and Chrysler made two types of V8 engines of the same displacement e.g., 350 cu. in. small-block and 350 cu. in. Big-block. The small-block engine was an enlarged smaller displacement engine (e.g., GM enlarged the 283 to 327 then to 350 by boring the cylinders). The big-block engine was a completely different basic engine size even though it displaced the same as the enlarged small-block engine. Thus, as vehicles grew smaller and more equipment was stuffed into the engine bay, the small-block engine was favored over its larger brother.
- Small Cowl and Chassis Bus Type
- Depicted by light-duty, non school bus shuttle coaches using a van or RV cutaway chassis.
- Small end bearing
- The smaller bearing of the two on a connecting rod and through which the piston is attached; usually fitted with a plain bearing or a needle-roller assembly
- Small gear lever
- Colloquial term for Transfer gear lever
- SMC
- Acronym for Sheet molding compound
- SMEC
- Acronym for Single Module Engine Controller (replaced with PCM)
- Smog
- Fog made darker and heavier by chemical fumes and smoke. A fog-like layer, often brown in color, that hangs over many areas under certain atmospheric conditions. Smog, a contraction of the words smoke and fog, is compounded from smoke, moisture and numerous chemicals produced by Combustion (from power plants, automotive engines, etc.) and from natural and industrial processes. Formation of smog is aided by the presence of sunlight which reacts with many chemicals and Combustion products such as Hydrocarbons and oxides of nitrogen to form other more noxious Compounds.
- Smoke
- The visible product of combustion; a common problem with diesel cars when starting or pulling hard, caused by too much fuel resulting in black smoke, oil (bad rings/piston, valve seals, etc.) resulting in blue smoke, or blown head gasket so coolant getting in the combustion chamber resulting in white smoke.
- Smokey on four legs
- Trucker slang for a horse-mounted police as in "There's a smokey on four legs at the next corner."