I would argue I can still say it /can/ cut off 50 minutes.

If you do a comparison of a 600 mile trip at 60 vs 55 you’re pretty close.

But yes, to be pedantic and more exact, you are spot on that it will get you 50 miles closer.

But in real world examples,

If you’re traveling 700 miles.

65 vs 70, 70 will reduce your time by 43 minutes.

So in certain scenarios, 5 mph difference must be able to save you 50 minutes ! ;)

(I do understand your point, and you’re correct. I’m just poking fun at it- my point with the mph difference is because 50 miles doesn’t have the same translation for most people at 50 minutes, but is a more accurate data approach. )