I just bought a used 5 speed 03 civic si. It has manual overdrive, is my 5th gear considered the overdrive or is there some other way to get it to kick in. I hit 3k rpm goin 60 on the highway in 5th that doesn't seem right.

Yes 5th gear is overdrive I believe... it doesn't really do much though as the gear ratios are so short.

Those RPMs are normal.

I guess you misunderstood the term overdrive... It's the gear ratio itself, not something you can turn on-off. It's not a truck with reduced gearing, FYI...
Si's a sport type, so they have short gearing, higher RPM - wasn't that the reason you got a Si anyway? Or did you not know what the Si trim is?...

Why are you concerened? Are you getting crappy MPGs?

Im getting pretty good MPGs it was just a knowledge question.... i knew what the si trim was long before i got it i just didn't expect 5th gear to rev as high going 60 thanks for the info.

yeah, any gear ratio where the transmission input shaft spins slower than the transmission output shaft is overdrive. that's 5 gear on your '03 si.

oh, btw, did you know that in 4th, your civic's gear ratio is 0.92. 4th is supposed to be close to 1:1 but technically, on most cars, it is also an "overdrive".
just in case you're wondering your 5th gear ratio is 0.74.