Just increased some values in the firefx.dat increasing burn time for some things like petrol wood carpet etc

UPDATED
--------------
dramatically increased burn times for bushes, leaves, grass paper hay and petrol increased ignition strengths slightly
Feel free to play around with the values to your liking
SHORT VIDEO DEMO here:

https://www.youtube.com/watch?v=QQHlUKEUotg&feature=youtu.be

don't forget to backup UPDATE.rpf if dragging and dropping the file doesn't work use the + icon in OpenIV and make sure you enabled admin edit mode!
Open UPDATE.RPF in the GTA V update folder using OpenIV
drop this in the /common/data/effects/
close archive.
done.

enjoy :-)
=================================
NOTE TO MODDERS: You are not limited to editing files that exist inside the update.rpf any files that exist in any of the x64*.rpf files can me modified as long as you keep the directory structure within the archive consistent anything in update.rpf will be loaded first so you may choose to modify a texture placing that modified texture in the update.rpf archive will override the pre-existing texture in the main GTA V Archives.