Nope, not the same thing at all! If you use the route planner, it will plan routes based on a full fuel tank, regardless how much you have in it now (or ever).
That way, you're not maximizing the range of your ship if you think you're "doing better" by running with 1/2 a tank. Yes, this works for manual jumps, but how often do you do that?
Generally speaking, if needed, I run to about 1/2 full or two+ maximum-ranges jumps left before I look carefully for scoopable stars. Just pop open the Galaxy Map and look for these stars in my route, or worst case, I jump to a nearby star that is type:
Fill
My
Big
Kettle
And
Go!
Almost zero chance of running out of fuel if you have two 35LY+ jumps in the tank before you commit, since as other have mentioned, an "75% jump" is a tiny proportion of fuel compared to a "Maximum Effort" jump. If you have 36LY range, there are
lots of stars in 75% of that range!