O Gauge --- scale vs traditional size question???

Scale locos for the most part will not run on 031.  If they did make it around the curve the overhang would be pretty sad.

 MTH Product  that is classified as Premier or Scale, usually O-72 for Steam, but some Diesel's and large Gas Turbines are classed as Premier,  O-72 as well. Though some  Diesels will track on O-31like F3's and 44 Tonner's but are still considered Premier due to the level of detail on them.

MTH Rail King is what Lionel and others classify as Traditional size, usually track at 031. But, MTH also has Rail King Imperial that is a little larger than the starter set Rail King Traditional size product, with almost scale detail and options. 

It can all get a little complicated but go with the equipment that best fits your layout and visual wonts.

Have Fun.   

No, minimum curve is NOT a sure-fire way to determine it's scale.

It basically falls into the following categories:

• O-27 (Basically 1:64 on O gauge track)
• Standard/Traditional O - selectively compressed - think Postwar O gauge items such as the 6464 box cars. Some items are essentially scalein size such as the 773, F3, NW-2
• Scale - pretty darn close to 1:48, but allowances made for tight curves
• P48 - rivet counter - everything is 1:48, down to the 2 rail track  - pretty much insane.

This has been discussed many times on this forum and elsewhere:

http://www.thortrains.net/carsize1.html

https://ogrforum.com/...andamp-o-27-car-size

As for determining from the Lionel Website or Catalog, best to look at this:

Of course there are exceptions to everything, If you want a very detailed 0-6-0 switcher buy a Premier steam engine. It should run fine on 032 track. Don

Best bet is to get the product number and put in in Lionel, MTH, or whoever's website. The product description there should let you know if it's scale or not.  

OTOH there is MTH Railking that is "1 : 48 Scale Proportions" (scale):

In the old days (PW) Lionel "Standard O" was usually very close to scale like this Standard O Gondola:

MTH makes Both "Premium" and "Railking" modern (frameless) tank-cars. They bill the premium cars as "scale" and the Railing version as "semi-scale" but I actually think the Railking version LOOKS closer to scale. Although a [scale] foot narrow these cars are the correct height whereas the Premium tank-cars are too tall and because they are full scale width LOOK (to me, this is subjective) oversized; bigger than life. 

If you remember, the turbine was sold as a 027 engine, #2020 and the #681/671 as a O gauge engine. Also in 1954 Lionel came out with a full size F-3 the Texas Special made for 027 track. It only had a single motor but was a nice engine with other 027 F-3s to follow. The MPC F-3 followed the same design with single motors and would run well on 027. Don

After about a year studying and asking guys at the Hobby Shop and some serious  therapy I get it now 

I asked (more or less) about this last year before I bought a Lionel #6-28005 PRR E6.

It was (and still is) listed on their website as "Traditional Scale". I took the word "Traditional" to mean smaller; like 0-27. I took "Scale" to mean full-on 1:48. It has the same body, tender (and probably other parts) as their  #6-38036 Long Island Consol, which is listed as "Scale". I took a chance and bought it; it is indeed O "Scale" 1:48 size...and is awesome.

Why the manufacturer/importer would list models of the same size/scale as (basically) 2 different things is still a mystery to me...

Mark in Oregon

PS: Please note that the term "Gauge" is/was not part of the issue...unlike many earlier post-war releases, like the 6-8-6 mentioned above.

Lou1985 posted:

Best bet is to get the product number and put in in Lionel, MTH, or whoever's website. The product description there should let you know if it's scale or not.  

Just to add to Lou's comment, more specifically both Lionel and MTH - on their respective 'web' page - list the minimum curve required (for engines) in the list of features because this seems to have become an important issue for more and more potential purchasers.

The reality is with traditional items being selectively compressed is that some of them don't require compression. Therefore, it is possible to have items that are of a traditional heritage, yet ALSO scale in size. Some manufactures also account for the level of detail (such as molded in details vs separately applied) - hence the differences in the items @Strummer listed despite sharing some base parts.

gg1man posted:

 MTH Product  that is classified as Premier or Scale, usually O-72 for Steam, but some Diesel's and large Gas Turbines are classed as Premier,  O-72 as well. Though some  Diesels will track on O-31like F3's and 44 Tonner's but are still considered Premier due to the level of detail on them.

MTH Rail King is what Lionel and others classify as Traditional size, usually track at 031. But, MTH also has Rail King Imperial that is a little larger than the starter set Rail King Traditional size product, with almost scale detail and options. 

It can all get a little complicated but go with the equipment that best fits your layout and visual wonts.

Have Fun.   

Let’s be clear.

MTH Premier locomotives are all scale dimensions. Pretty straightforward.

MTH RailKing locomotives are usually traditional size, but the brand also includes RailKing Scale (usually former Premier models with less detail). The MTH RailKing Imperial line is usually scaled down more than MTH’s other RailKing models where it concerns larger prototypes, but does include more detail.

The MTH 44-ton diesel is an all diecast Premier model. It runs on O-27 curves. As does the MTH Premier A5 0-4-0 switcher, a highly detailed steamer. In fact, all of my four axle Premier diesels and many of my Premier steamers such as the 0-6-0 B6, will run on my O-27 curves. So curves can’t reliably be used to determine whether a model is scale or not.

Lionel’s new seven-digit numbering system, effective in 2019, does include scale or traditional coding.

-First two digits are the year of introduction.

-Next two digits are the primary marketing category. (For example, 26 is for full O scale rolling stock, 28 is for O traditional rolling stock, 31 is for full O scale steam locomotives, 32 is for O non-scale steam locomotives, 33 is for scale diesels, and 34 is for non-scale diesels)

-Last three numbers are the product stock number.

Take, for instance, Lionel no. 2031261. That’s the excursion version of the Big Boy. Lionel will make it in 2020 (thus “20” is the first two digits). It’s a properly proportioned O scale model (thus the “31” in the next two digits) and is stock no. 261.

Lionel no. 1932040 is Pere Marquette Berkshire #1225. It’s the LionChief Plus 2.0 version of the Polar Express Berkshire that has been included in trainsets for more than 15 years. It will be introduced this year (19), is traditional sized (32) and carries a no. 040 stock number.

Here’s a chart we have been sharing on the forum indicating the product coding for the two digits that follow the year.