ΔE 69.7, loose: different enough that you should pick on purpose. Acid is noticeably darker, much more muted, cooler than Speed Yellow.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 70). Acid is noticeably darker, much more muted, cooler than Speed Yellow.
The same difference applies the other way round: Speed Yellow is noticeably lighter, much more saturated, warmer.
ΔE is the colour difference between our two swatch estimates: under about 6 is close, over about 15 is loose. Real paints also differ in finish, coverage and how they thin, so test before you commit.
See Speed Yellow on the colour wheel See Acid on the colour wheel
All matches: Speed Yellow equivalents · Acid equivalents