Peterbilt
Probably a bad vehicle speed sensor.
Two or more, depending on customer specifications, model, etc.
Typically, 17k - 19k for a three axle freight truck.
Yellow for the tractor brake control valve, red for the trailer supply valve.
102 inch maximum width without requiring an oversize permit.
102 inches
You should probably be a little more specific. Transformers is a long standing franchise, and the cartoon series alone has several 'generations'. Traditionally, in the cartoon series, Optimus Prime was a red Cab-Over-Engine tractor (he was shown as a Peterbilt 379 bonneted tractor in the movies).
Depends how wide the tires are set
Peterbilt makes Class 5 through Class 8 trucks, and the weight varies greatly between these models. Additionally, the application affects the weight - say, for example, you have a Peterbilt 330. Whether it's a single or tandem axle, what type of body it is, etc. will affect the tare weight. For a tractor unit (such as the 379, 389, 378, 359, etc.), you can expect a tare weight between 16,000 and 20,000, depending on the configuration.
There are two typical widths which is 96 inches and 102 inches. This is the trailer width and most of which today are 102 inches.
The more high end tractors are the Kenworth W900L, Peterbilt 379EXHD, Volvo VNL64T770 and VNL64T880, the International 9900ix, and the International Lone Star.