Just realised that i can de-activate the speedo by pressing F3 and unticking that box, whew, back to 60fps.
It gets even worse when in a flying vehicle, like the vortex, as theres 2 dials, a speedo and an altimeter?
with both of those onscreen it went down to 10-15fps....
with only the speedo onscreen it gets down to 20-30fps...
So, in conclusion,
if the speedo's mess with ya FPS (its a rhyme!!!)
press f3 and disable it.....
EDIT [RW]Tu_Madre was having the same problem, so i told him to deactivate the speedo and it fixed it.
/EDIT
This could potentially drive people away from the server if their comps are slow, coz they might not know how to turn it off - or might not wait long enough to. just a thought.