Have you read the TimeDelta article in my signature? It should cover it as you want. The idea is that objects move at a constant speed in real-world time, independent of the framerate, rather than speeding up if the framerate is higher. So:
Set X to .X + 1
Every second, this will move the object 1000 pixels sideways at 1000fps and 10 pixels sideways at 10fps. A difference of 100x in speed depending on the framerate!
Set X to .X + 1 * TimeDelta
This will move the object precisely one pixel every second, no matter the framerate. Obviously multiplying by 1 is redundant, but it makes it clear that it's one pixel per second.
If that number is a private variable or some such, you still need the TimeDelta! It makes no difference if that number is hard-coded or a variable, you'd still need to do it like this:
Set X to .X + Object('Speed') * TimeDelta