I'm interested in installing one of those EZDrain devices in my car's oil pan.

They don't sell one with the M20x2.5 threads, which is what my car uses (I believe) as the drain plug for the oil pan. They do sell one with 3/4-16UNF threads, which seems to be an "as equal"?

Does anyone here know if they are interchangeable?

Thanks.

They are not. My car's sump drain has an Imperial (ie UNF or UNC) size, not metric. But your later AJ16 may well be metric like all UK Fords are.

Interchangeable, afraid not.

16 threads per inch is a pitch of just over 1.5mm. The M20 x 2.5mm has a thread pitch of, you guessed it, 2.5mm. No chance of one fitting the other.

3/4 is 19.05mm you could drill and re-tap for M20

Most of the metric stuff was introduced long time before Ford was involved.
My 1992 XJ40 (build under Ford, but designed a long time before) has only imperial threads in suspension parts.
I don't know what the thread is on the sump drain plug, but I bet it's metric.

For the answer to the OP's question: I agree, these threads are not compatible.

The drill size for an M20 thread is 17.5mm, for 1.25mm thread depth. There will be only 0.5mm thread depth in this case at best, so it will be sure to strip at the first opportunity.

Sorry I was thinking M22 which is 19.5m

Just buy a pump dude. Stick the hose down the dipstick tube and go inside for some coffee. I haven't pulled a drain plug in quite a while.