All ground vehicles are strong against Light Infantry and weak against Ground Defenses.
Armored Cars are your Tier 1 ground vehicle. They have a medium load capacity and moderate speed but very low attack, defense, and health.
AFVs are your Tier 2 ground vehicle. They have a high load capacity and decent speed but low attack, defense, and health.
Heavy Tanks are your Tier 3 ground vehicle. They have a very high load capacity, decent speed and power, and moderate attack, defense, and health.
Titan Tanks are your Tier 4 ground vehicle - the best ground vehicle you can produce. They have an incredibly high load capacity, Speed, Power, Defense, and Health.