The naming schemes usually involved letters and numbers, and generally indicated things like:
* Series (e.g., 100, 200, 300): This roughly corresponded to weight class and payload capacity. A higher number usually meant a heavier-duty truck.
* Letter prefixes: Sometimes letters were used (like "W" which sometimes indicated a 4x4 or "D" which might signify a particular configuration). These prefixes and their meanings varied across the years and sometimes regionally.
Therefore, to understand the difference between a hypothetical "d200" and "w200" Dodge/Ram pickup, you'd need to know the specific *year* of the truck. Without that year, any comparison is purely speculative. It's possible the "d" and "w" were just dealer or internal designations rather than official model codes. If you have a specific year in mind, I might be able to offer a more accurate comparison.