Yup, I prefer using the GP3 editors too - much more user friendly. But as you wanted a tutorial on using Ralph's cars in 16 bit here goes.
1. Edit the line underneath in the f1graphics.cfg to a value of 0, then save changes
[RELEASE] Enable 32bit mode if available NB. If Windowed then is forced to desktop format
Just out of interest, run GP4 and see if you have a speed increase. With only this one line edited you'll notice that you can still play with the advanced graphics options. Don't touch these for now though. What appears to have happened is that GP4 is now optimised to run in 16 bit mode, so some options are slightly lower - bear with it.....shut down GP4.
Run GP4 master
Select wad workshop
open cars.wad file by using the load wad file option
select extract all files
you'll be asked for folder to extract all these tex files to eg: D:\My Documents\GP4 Files\Editors\GP4 Master\Cars Directory
In this folder live all the tex files for the carskins, tyres, helmets etc..
Now as an example, I'm going to use Ralph Hummerich's Williams as he posts his cars as tga files. Some painters actually make the tex files before uploading so just replace these as required.
In GP4master select tex workshop>load tex file>hi_williams_1 .tex
click replace selected file button
open relevant tga from the carskin pack
click downsample textures and agree to warning - this gives 3 more tga's each reducing in size by .5 each time(512x512/256x256 etc)
click save tex file
repeat for the remaining textures not forgetting the cockpit
Now, the clever bit. Actually within the folder you have made, COPY(not cut) the 3 hi_williams_x.tex files and paste outside the folder remove the hi_ prefix so that hi_williams_1 .tex becomes williams_1.tex for and so on. Cut these new files and paste them back in the folder from where you cut the originals. This will replace the 3 lower res tex files that are in there.
In GP4 master, go back to the wad workshop and select create wad from directory.
* Remember to use the whole folder you created and not just the cars folder within it*
Give directory name again: D:\My Documents\GP4 Files\Editors\GP4 Master\Cars Directory
Give wad name eg:
D:\My Documents\GP4 Files\Editors\cars.wad - do not create this wad file in the GP4master folder as there's one there already which GP4master uses.
Put this newly created wad file into your GP4 folder.
Try it out! Just keep a backup of your original cars.wad file as it is a lot of arsing around just to change one car.
I make no apologies to those who already know this, but there's obviously some people around still struggling so any help is a plus eh Mortal?
I'm going to try some different cars using the prefix dropping method now - will let you know how it goes.