A 2.5t ramp will be fine with a car that weighs under 2t...
but are you talking garage type ramp, or the wedgy things that you can use outside the house...
With the garage ones it always a good idea to bang a prop under it though before getting under and working on it though, unless its a modern fancy ramp with all the self locking measures...
The DIY ones are ok, but can be a bit unstable side to side if you have to swing on bolts to get them undone...