Looking to find a trailer for ROTF prime to make into an accurate DOTM Prime, and I was wondering what scale it is so I can find as close as possible.

hmm. Prime in truck mode is about 9 1/4 inches in length. My guesstimate for the trailer would be about 12 inches in length , 4 inches in width, and 5 1/2 inches in height.

The key to figuring it out is the width. The D.O.T regulates that a truck can be no wider than 100 inches ( 8 feet 4 inches ). Measure the width of the toy and do the math to get 100 inches.

closest scale is 1/32 I compared the wheel base to another 1/32 scale rig, and its pretty dang close.

His robot mode is just a tad taller than the 1:35 scale DMK-01 kit, as well, but his proportions are a tad off, with slightly stumpier legs. So 1:32 sounds about right.

Thanks for the responses. Not worried about robot mode too much. Just looking for a trailer I can retrofit into Primes.

Some measurements of a real Peterbilt 379 (though the movie one I believe is a highly modified 359 with many 379 parts) Note that wheelbase, overall length, nose length, etc are all OPTIONS on trucks like these--you order it how you want it, and they build the frame to match from the raw rails. Some options can vary by a foot or more--wheelbase by several feet I believe. 270in wheelbase 29ft, 7in long overall 94in wide front bumper

They used a 1997 Peterbilt 379 Long Hood Semi for Optimus Prime. In Big Rig parlances they measure the rigs by BBC (Bumper to Back of Cab) in inches. The ROTF Leader Class Toy is 6.25 inches BBC, & on the full size Optimus the BBC is 127 inches BBC. With that in mind the Leader Class Optimus is roughly 1/20th scale compared to the full size Optimus. Trailers these days are 53 FT in length and 162 inches in height by 101 inches in width. So your scale trailer will be 4.97 inches wide, 8.64 inches tall, & 31.299 inches long. Hope that helps!!