I was trying to find an approximate scale of ROTF leader class Prime. The Peterbilt 379 long nose is 127" BBC (Bumper to Back of Cab), and Leader Prime is about 6¼" BBC. If I did everything correctly ROTF Leader Class Optimus Prime should be approximately 1/20th scale.

Could someone please tell me if I did this right, and if my numbers are correct too?

 

Without looking at the math, that can't be right. Alternators are 1/24. Leader Prime is definitely a smaller scale than the alts. 1/20 would put him bigger than the Alts. Just eyeballing it he seems closer to 1/32.

Remember that RotF Prime has a nose that is too long. You'll get all messed up measuring from bumper to back of cab. Prime makes up for it by being too short from the back of the cab to the rear tail lights. You'd have more luck calculating scale off of the whole length or the height of the cab or something.

 

Does anyone know the entire length of a Peterbilt 379 long nose, bumper to bumper?

 

Perhaps your measuring from the bumper to the back of the sleeper instead of to the back of the cab. Not sure if BBC includes the sleeper or not.

Try wheelbase.

I found a 1:32 model that is 11" in length. Cheebs might be right.

 

VULCAN, YOU GENIUS EMOTIONLESS BASTARD!!! (JK)

Leader Prime is 11" long, so that answers my question right there! Thanks man!  

 

So the scale is 1:32 right?

 

Yes

 

Long since covered in the Scale Project thread, guys.