Do You Run 18" and 21" Passenger Cars Together?

I generally run passenger trains of all the same length and paint scheme. The exception is head-end cars. 72' baggage and RPO cars frequently ran in trains withe 84' passenger cars, and I will do the same. In fact, except in extra-fare streamliners and sometimes even then, real railroads often ran a mixture of cars, with heavyweights running together with streamlined cars and various lengths and paint schemes mixed up. Most model railroaders are more fastidious than the prototype railroads in running trains with all the same kind of passenger cars. 

For the New York Central at least, about the only time you saw perfectly matched passenger consists was for publicity photos after the debut of a new train. Shortly thereafter, most trains were a dizzying mix of head-end cars, heavyweights, and streamliners.

I'll have to agree with Southwest Hiawatha - unless you are into truly hardcore prototype modelling the matched trains simply look better in our perfect miniature worlds.

Can you spot the 21" passenger car in this video?

Most of my small fleet of passenger cars are 21", but I do have 3 18" cars that I run with them when I feel the urge.

I Googled "Passenger Car Consists" and got a bunch of hits.  One of them is an article from MR on "Pike-Size Passenger Trains":

http://peskar.org/model_trains...%20Railroader%5D.pdf

Pretty good stuff with some prototypical data thrown in.

Here's another good link:

http://www.trainweb.org/fredatsf/

I do, but I don't have any long sections of straight track.  That could possibly make a difference.

However, I believe that, when trains are running, the perfection of detail or weathering does not matter as much as when they are sitting and being examined.

No, I do not mix different sized passenger cars. I think it just looks better with one size.

No don't mix 18 & 21 inch cars. In fact I have been selling off the 18" cars.

Yep...its not like it is a big deal.

I vote with Southwest Hiawatha...too perfect, to me, looks artificial and contrived.

One of my favorite last passenger trains, the Yampa Valley Mail, ran whatever loco

or cars would do the job for the day, although often headed by an Alco PA in its later

years. Heavyweights and lightweights, in this short train, were intermingled.

I am with the others that say mix them up.  I think it looks more interesting that way. Even the excursion trains today use a mix up on all I have seen.

I run 21 & 18. I have a set of five 21" & set of 3 18" Pennsylvania pulled by a K-4.

Other than baggage and RPO's, the length difference is very noticeable.  I have a set of 18" streamline cars.  They look fine by themselves.   I would not mix them with 16" or 21"cars.  You can run a set of 16" coach/commuter cars next to a set of 18" "long distance" (aka a different train).  The eye/brain will accept this unless you start throwing in 16" sleeper/diner/dome cars and then you are back to Why does that train look weird.

BTW, the 21" cars are awesome BUT you need a lot of real estate for them to look good.  O-110 or better or the cars start taking out stuff along the ROW or look silly.