u/Fart_Bard

TL;DR: steal a tank

Let me preface this with a pre-emptive apology to older players if I'll be repeating stuff you already know. Feel free to comment though if I got anything wrong or if you've got something to add. The following info can be used to speedrun all Los Santos gang territories in one sitting within ~2 hours if they're lucky.

The core rule is only CJ has to be on foot, inside the enemy territory, at the very instant the enemy gang members die, in order to trigger the gang war in the territory where CJ is standing. Following from that, it means:

• You can snipe/rpg them from outside the territory, or throw molotovs at a group then sprint back to the territory where you want to trigger a gang war before they burn to death.
• Sniping with a few seconds pause in between shots is the safest to avoid a wanted level, molotovs/RPGs/etc are sure to attract police attention, especially if there is collateral damage (we'll come back to this in a bit)
• You can kill enemy gang members inside their cars, again whether their car is inside or outside the territory, the gang war will be triggered in the territory where CJ is standing at the moment you snipe the passengers or blow up the car
• It also doesn't matter whether they're Ballas or Vagos: if you're standing in Ballas territory for example, but you killed 3 Vagos or other combination of Ballas+Vagos, the gang war in the Ballas territory will be triggered. Probably an oversight during development, inadvertently foreshadowing them working together under Big Smoke.
• Using the above, for the two tiny territories (you know which ones lol), it is best to take them first to guarantee high spawn rate of enemy gang members regardless of which territory they are standing/riding on, before taking the surrounding ones
• CJ needs to be on foot only to trigger the gang war, before and after that you can use any vehicle: ride it into enemy territory, snipe a few enemies, then hop back in. These vehicles can include a Rhino stolen from Area 69 or from police at 6 stars wanted level, or even the Hunter or Hydra from Verdant Meadows
  • Hydra is doable since it can hover and the rockets have splash damage, but it has low health so it's prone to enemy ground fire
  • Hunter is a little easier, the cannon has auto-aim, but it also has low health
  • Rhino has high armor and is best suited for urban warfare.
• Going back to the part about wanted levels, having police chasing you in between gang wars is tolerable - you can outrun them in the Rhino, or use the horn to keep them at bay - but it is annoying at best and risky at worst, especially with police helicopters that can damage the tank at 3 stars and up
• The tank has very high health and can withstand lots of small arms fire, but it is not invincible. It can still be destroyed if it's been shot at too long without repairs. It doesn't give off as much smoke when damaged but the engine sounds are still noticeable. Fire can also seriously damage the tank. It can survive one fire but not two.
• Obviously Pay-'n-spray doesn't repair tanks, but as with any other vehicle, you can put it in any garage, wait for the door to close, then it will be repaired for free, even ones that are on fire or exploded. When parking the tank in a garage, careful not to put the left side of the tank too close to a wall, or CJ will not be able to enter anymore, since it doesn't have a right-side/passenger-side entrance
• Another great thing about the tank is if one of your territories comes under attack, you can just start a vigilante mission then immediately cancel it, and it also cancels the enemy attack.
• Enemy waves almost always spawn at points on a road behind your field of view.
  • This can be exploited on long roads, look away from where you want them to spawn, then they will spawn together at a single point
  • On three-way junctions, look towards the "fork" on the road where it splits, and they will spawn in a clump on the single road behind you
  • This is a little harder to do if close to four-way junctions
• If done right and with a little bit of timing with the turret fire, the tank can one-shot entire waves with its turret
• If there is enough space like in the central/eastern freeways on the video, you can just drive over all of them with the tank, without even firing the turret

AFAIK all of the above applies to PC, console, or mobile.

For added fun, here are the PC mods used in the video:

• Ragdoll physics
• Tank cannon
• Tracer rounds
• M1A2 Abrams Rhino skin with optional custom edits

Sorry about the wall of text, I really should be working right now I'm actually just procrastinating :p