A shift light is a warning lamp fitted to vehicles in order to indicate to the driver that maximum RPM has almost been reached. Ideally a shift lamp will illuminate at the engine speed beyond that which delivers the maximum BHP such that the BHP before and after shifting is the same. Accelerating the engine beyond this point is not conducive to rapid acceleration. In use a shift light allows the driver to judge the exact point that a gear change should be carried out without having to glance down at the tachometer. This also increases safety for the driver by keeping his focus on the track at all times.
Beginning in the early 1980s, many United States-market vehicles equipped with a manual transmission began to have shift lights as standard equipment; these would usually signal for an upshift at an engine speed that provided maximum fuel efficiency, lower than the ideal engine speed for maximum BHP. The reason for this was, for a time EPA fuel economy testing rules stipulated that shift lights would be followed on vehicles so equipped- thus, they were calibrated for optimum fuel mileage on the EPA test cycle. Some in the 1980s even had buzzers to alert the driver it was at a certain rpm.
This article about an automotive part or component is a stub. You can help Wikipedia by expanding it. |
Famous quotes containing the words shift and/or light:
“The success of great scholars and thinkers is commonly a courtier-like success, not kingly, not manly. They make shift to live merely by conformity, practically as their fathers did, and are in no sense the progenitors of a nobler race of men.”
—Henry David Thoreau (18171862)
“The light of her face falls from its flower,
as a hyacinth,
hidden in a far valley,
perishes upon burnt grass.”
—Hilda Doolittle (18861961)