You might be confusing spec with roughness. but either way, White is most shiny, black is least shiny. and actually the diffuse should be darker, and the spec lighter. not both lighter.
still need some differential spec on the car. and having a bit of grunge would help a lot. maybe a noisy spec would help. Your reflection is reeeally intense.
Wow, spec is boring, tiles are all about the spec, the floor looks 100% clean. Any dried liquid would affect the secular and gloss, go crazy with it and push the specular farther.
spec is bright! Have you tried crazy bump? you can download 30 day trial :) from a diffuse map it can generate normal and spec. it's a good place to start.
Usually final but currently I'm working on something without finalized specs so I go with the largest size I could imagine it to use and will shrink it down once the specs are set.
Have you looked into colored spec maps? The black and white spec map on the gun especially makes it look like plastic instead of a metallic material. My 2 cents.
The black shouldnt be a problem for the spec. Spec is additive so you use screen or addition to apply it. any black areas are just ignored. what other layers are you using?
Ha yeah, Intel GPUs are really not recommended for our software unfortunately. (Also your GPU is just below our minimum specs : https://www.allegorithmic.com/products/tech-specs )