Does anyone know how to increase the communication rate between clients?

My understanding is that all the settings in Studio impact your client only (and possibly only Roblox Studio instead of the client, I'm not sure). Thus, Perci1 is correct. Server-client communication is already quite quick (Audio Visualizer by Dummiez has a TextLabel showing your ping (among other things), and mine shows a ping of 84ms, occasionally jumping up to 151ms - I have gotten better on other non-Roblox games, but not always). When information has to travel from Client A to the server to Client B, pings add up.

All games have to work with this; often games will attempt to predict player behaviour to make the animations smoother. The idea is that you keep animating enemy vehicles with your best guess of where they should be at the current time (ex based on previous control inputs from the player that owns that tank). Should the server later give you information on the current status of an animation (or position of a model), you then update the local animation/part/model with that information.

Some game simulate all the physics on the server. The client may also simulate the physics, but whenever there is a discrepancy, the server's version of reality is the one that is kept (which may cause a "jump" in your character's position whenever the client receives new information from the server). Compared to this method, some advantages/disadvantages of simulating things on the client and transmitting that information to other clients (as you are currently doing):

Advantages -Player vehicles will respond immediately Disadvantages -If anyone is using a compromised Roblox client (I don't know if any exist at the moment or how common they might be), they will be able to teleport anything assigned to them via SetNetworkOwnership, including their vehicle -Opponent tanks may appear to teleport more than using a Server simulation since their tank simulations are being done on someone else's client.

In comparison, using Server Simulation (where all tanks are simulated on the server; clients can attempt the simulation to make smooth animations but their results are not transmitted) sacrifices some of the player vehicle responding immediately but lessens the opponent tanks "teleporting".

Regardless of which strategy you use, you might be able to make things look better by animating all enemy tanks on all clients (potentially through the use of Local Parts -- parts that exist only on the client, accomplished simply by clients generating Parts/models and/or by putting said models in your camera (the latter only being required if you aren't using FilteringEnabled). Note that Local Parts are not officially supported, though they've worked for years.)