Virus says:
Hu yeah i don't really get the difference between "files" and "data" but anyway, I found them thanks.
156 HD texture files to edit ! Here we go !

You are not only one wondering. In windows, there are currently 3 places for application data: "Program files", "Program data" and "Application data". Soon, they will add "Application files" and "More data", I guess

You don't have to include 150 files in your mod. Just take the most important ones and make them smaller...so that you will end up with a mod size of around 40mb.
I think I found a good compromise between "beauty" and size. Loss of quality is only barely visible in this mod and it is only 45mb big: http://vinummusik.de/Trackmania2/Mods/AncientEgypt_Canyon.zip

Textures automatically scale ?

Yes of course, just keep the dimensions correct...then scaling will work. I noticed though that some specular textures can only be scaled to a certain point. So if you make some Specular texture for example 64x64 pixels in size it might show up bugged ingame. But I haven't experimented with this much yet.
Also I think textures that you can't scale are the ones in the "DecalsImage" folder. But that's only an assumption based on two textures I worked with in that folder.

Ok thanks.

Ok, so they scale upwards. But what if you do higher resolution textures? Does it work (mm.. ultra hi-res texturepack )?

Dunno, I wasn't crazy enough to try this yet and I don't really see a point in doing it. I doubt the quality would improve visibly. And you would have to extend the current textures to four times its current size to meet the dds specification. So the mod would probably be 3GB total in size. Noone would download that ^^

HawkGer says:
Dunno, I wasn't crazy enough to try this yet and I don't really see a point in doing it. I doubt the quality would improve visibly. And you would have to extend the current textures to four times its current size to meet the dds specification. So the mod would probably be 3GB total in size. Noone would download that ^^

You never know Not every texture needs higher res, but those cliff textures are a bit blurry.

Cliff textures are already quite an high res one of which is 4096 x 4096 and others being 2048 x 2048

Skeleton says:
Cliff textures are already quite an high res one of which is 4096 x 4096 and others being 2048 x 2048

But they're streched to quite big areas... Next one is 8192 x 8192, which is quite big
Not that I'll ever use mods anyway Maybe if somekind of "Change default mod" option would be added :/