are/were drunk.

In common usage, the first implies that they actually are drunk and the
second implies that they are not.

1. They talk as though they are drunk. PRESENT TENSE. BEING SAID IN THE PRESENT ABOUT PEOPLE WHO ARE TALKING NOW.

2. They talk as though they were drunk. TALKING NOW ABOUT THE PAST.
For example: John is telling everyone about his date last night. They did some crazy things. He talks as though they were drunk.

Thanks, George and Punkey.

It's interesting that both of you give different explanations.

PUNKEY says the verbs differ in tense.
I say they differ in mood (indicative vs subjunctive).

I have read in an English usage book the explanation given by you. But then grammarians are prescriptive. That's why I posted the sentences here.

Ignore me. I've spent way too much time translating Latin.

Thanks, George.

On the contrary, I agree with your explanation since it is the same as the explanation given by the English usage book that I have read.

George is correct; PUNKEY is not.

1. They talk as though they are drunk.
With a verb in the present tense before 'as if' or 'as though' (e.g. 'talk', the use after these phrases of a real tense (are) means we know or very much suspect the supposition is true (they are drunk).

2. They talk as though they were drunk.
The use of an unreal tense (the past subjunctive or the past perfect subjunctive 'were') indicates that we suspect or know that the supposition is untrue (i.e. they are not drunk).

But...

They talked as though they were drunk.
However, if we put the verb before as if or as though into the past tense (i.e. 'acted'), then the verb following ('were') looks the same whether it is simple past or past subjunctive, and to know the meaning we must deduce it from the context.

That's (i.e. 'talked')

Thanks, George, Punkey and contrex.