bricklab

That was my best guess. I'm sure it was more of a "cutting cost" measure. I contacted Lego but never heard back. oh well...

I have 2 of the 8285 tow trucks, but they seem to be different versions. 1 has the silver metallic wheels and exhaust tips, and the other has all bluish grey wheels and exhaust tips. I checked each set of instructions and the set inventory list in the back is different, calling for the variations in part colors. Not sure why Lego changed it, but they are different. The all-grey wheels version still has the other parts being metallic, but not the wheels and tips...