If you've spent any time on Toyota enthusiast web sites, email lists, or babbling friends who seem to throw out groups of letters and numbers and not have a clue, you'll wanna take a minute and check out this page. Like most car manufacturers, Toyota developed an "internal designation" for each of their models. Enthusiasts picked up and started using these codes because they were less ambiguous.
Toyota's means of assigning model codes is fairly simple. The first group of letters specifies the engine family and chassis. The following numbers specify the design generation of the car.
When you reached this site, you most likely noticed "AE92 GT-S" plastered on the main page. So, let's use that as an example of how to read Toyota chassis codes.
Now, let's track the evolution of the Supra and its model code. The '81-'85 Supras were coded as "MA61" while the '86-'92 Supras were "MA70." The last Supra ('93-'97) was coded as "JZA80."
Notice that the chassis letter stayed the same. But, when the newer 2JZ-GE (or GTE for the turbo) engine was introduced, the first 2 letters in the last generation Supra changed. By now, you should've noticed that the generation code was raised to denote a new design. Now, that wasn't so hard, was it? =)
I'll get a scan of the different model codes and their associated pics f/ the TRD-USA parts book as
soon as possible...