2001 C5ster

A number of tuners allow you to modify your idle rpm.
Is there any advantage or disadvantage to raising your idle speed?

I can imagine fuel consumption might go up very slightly, but is there any other negative consequence? I can only think of good things coming from this.

95rtturbo

Greater fuel consumption, unnecessary extra engine wear, etc. Those are the 2 things I can think of off hand.

Indyzoh6

With large cam cars it helps to bump up the idle so it's takes less throttle to pull away from a stop, you get additional vacuum for brakes, your idle is smoother (aggressive lope sounds cool for a weekend car but the shaking gets annoying in stop/go traffic with a DD). Those are my thoughts.

Sigforty

If you are stock I would not touch it. If you have a modified car with a bigger cam, more idle helps as stated above.

73Corvette

About the only advantage I can think of, if stock and you have very low oil pressure you might be able to raise it a hair by raising your rpm's at idle... disadvantages are as stated above.