Tyre type information (wear and grip)

Hi!

Mortal asked me to post this information here, so I suppose you guys have not found this stuff yet.

Some years ago I've posted this thread in the GP3 forum and also this thread in the realgpx GPxPatch forum.

Last week people got interested again we we started discussing it again. My old excel sheet is gone for good so I had to search the data again.

It is about the properties of each tyre compound. If you look at this table you will find the decimal offsets of the grip and wear values for the compounds in GP4.exe. Unlike GP3, there is no separated wear curve for each dry tyre compound, but too curves. I've made some tests the first time I've found these values but I don't remember if each curve is assigned for two tyre types or if this will change according with the tyre compound chosen in the magic data file. Each non-dry compound has its own wear curve and all compounds have their own grip curve. The second table shows the values stored in these curves in original GP4.

Wear range is probably 0-255 (that's why I gave the wear offsets like they were only bytes, which I'm not really sure...but I don't think anyone would ever need values higher than 255). Higher values give faster degradation. Grip range is 8192-16832 in original GP4 (higher values=faster cars). I never tested lower values in any GPX game, higher values usually work but have a limit before giving negative effects.

Each line in the table shows the values used by the game depending on the track conditions.

Roberto Scandurra has created a nice GP3 editor for this, maybe he can make a GP4 one, I'll ask him. If not, I can create an editor, but I don't know when I'll have available time for doing this. If someone else wants to make an editor/tool for this, it would be nice.

I hope this is useful for someone. You can change the tyres behavior with this without using weird values in the magic data. I use this in GP2 with nice effects (you guys think you play an old game...ha)

Regards!

Roberto

ps.: I suppose the correct order for dry compounds is 55=Extra-Hards 54=Hards 53=Softs 52=Extra-Softs (well, there is only 2 two wear curves, so this is supposed with the assumption that softer tyres are faster), but there's so much time since I edited anything GP4 that I really don't remember.