M178 may refer to
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M-178 (Michigan highway)
M-28 is an east–west Michigan Highway System, state trunkline highway that traverses nearly all of the Upper Peninsula of Michigan, Upper Peninsula of the U.S. state of Michigan, from Wakefield, Michigan, Wakefield to near Sault Ste. Marie, Mi ...
, a former state highway
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Mercedes-Benz M178 engine, an automobile engine
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M178 gun mount, a mount used on the M109 howitzer
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