Type F is a relatively unsophisticated fluid that dates back to 1964, but was in use as factory fill until 1988 and is still commonly called for.
Mercon is used on 1988 and later Ford transmissions. It is a friction-modified ATF, and similar to GM’s Dexron II. Its spec is close to Dexron II, hence the existence of Dexron/Mercon products. It is good for most Ford applications back to 1980, except Type F or Mercon V.
Mercon V is Ford’s latest standard. Originally introduced in 1997 for Rangers and Explorers, it has since found wider use. Originally not for earlier models, it has now been cleared for use in earlier applications.
General Motors has two specifications:
Dexron II was the standard fluid for all GM transmissions requiring a friction-modified ATF up until Dexron III’s introduction in 1994. Many import transmissions also require an ATF that meets Dexron II specs, though there are some slight differences.
Dexron III is GM’s current friction-modified specification and is recommended for all GM automatic transmissions previously using Dexron II.
Chrysler also has several specifications:
ATF+2 or Chrysler MS-7176D is the company’s version of a friction-modified ATF. Fluids that meet this spec may also meet those for Dexron II and III, but not the other way around because it is more slippery.
ATF+3 or Chrysler MS-7176E was introduced in 1998 and supersedes ATF+2. Chrysler says ATF+3 should only be used in 1998 and newer Chrysler transmissions, though some earlier models can use it.
ATF+4 is the latest friction-modified specification from Chrysler for 2000 model-year applications and is currently a “dealer only” item.
In addition, ATFs that meet one of these specifications may serve import applications, but not necessarily. Plus, it’s a moving target, so old assumptions should not be trusted. Mistakes can be expensive, so always advise people to refer to the vehicle owner’s manual or the latest ATF application guide for the type of fluid required.