ΔE 9.8, close: similar, with a visible difference side by side. Engine Gray is a little darker, more muted than Smoked Blue.
Usually, if you are not matching paint already on the model. Close match (ΔE 10). Engine Gray is a little darker, more muted than Smoked Blue.
The same difference applies the other way round: Smoked Blue is a little lighter, more saturated.
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 Smoked Blue on the colour wheel See Engine Gray on the colour wheel
All matches: Smoked Blue equivalents · Engine Gray equivalents