Originally Posted by eddie g:
What's the difference between Large scale, standard gauge, 1 gauge & G gauge?
Standard Gauge, as in Lionel or MTH Standard Gauge today or in the past, is in a league of its own with 3-rail track that, at 2-1/8" between the outer railheads, is not the same as track used for the Large Scale categories.
Large Scale is an umbrella term for anything that operates on 45mm track, and that includes, but is not limited to, 1:20.3, 1:22.5, 1:24, 1:29, and 1:32 scale--generally the most popular Large Scale scales. Again, the track gauge for all is 45mm.
The term 1 Gauge also applies to a 45mm track gauge, and is commonly used throughout Europe and Great Britain. Marklin originated the term since they once had #1 Gauge, #2 Gauge, and #3 Gauge systems.
G Gauge is a term that was initially applied (somewhat wrongly) to LGB trains when they were initially introduced to the U.S. market. They were commonly referred to as "G Gauge trains" even though the true scale of most LGB equipment was 1:22.5 or thereabouts. Early on, the term came to be applied to nearly all trains operating on 45mm track, I suppose because it was easy to associate with LGB.
With the multiple scales that all operate on 45mm (#1 gauge) track, there's quite a bit of confusion in understanding the various Large Scale offerings and how they relate to each other.