I have been wondering about this for a while, what do the numbers mean on the motors? My car has a D15B2 (i think that is right), and then other cars have a D15A2, etc. etc. So what do all these numbers mean?

 

Here ya go engine list

The numbers stand for the liters... d15 is a 1.5 b18 is 1.8... and so on... As for the rest I really dont know. I think the first letter is the type of block and the last after the liters is the different style, or what not of that engine. As there were many variations of the same block over the years.