mercon V or mercon III ?

I have a 2000 ses bought used with 90k on it...It is 1/2 qt low on auto transmission fluid...But I 'm not sure of what to add.....Was Mercon V standard in these cars from factory?...or was dexron III in it.....Can Dexron III, Mercon and Mercon V be mixed......Auto zone says no....any help will be appreciated

Your car calls for Mercon V. I run Mobil 1 Synthetic in my 2000 and I have 128K on it.

I have seen some posts on the other boards claiming failures from using Mercon III.

BTW I have a press release from Valvoline saying that Their durablend fluid (semi-synthetic) is suitable for applications that call for Mercon V. Their bottle doesn't say it though.

Mike
:smokin:

Thanks, I guess I'll have to assume that the original fluid from the factory is still in it....and use the same.....what worries me is that Dextron III may have been used and from what I'm hearing, it doesn't mix with Mercon V