The Skybrary
Coolant System
Upgrade Category: Engine Upgrades
With a fast plane, this is better than a Port and Polish. On a slow plane, it's garbage.
Armor (mm)
Armor Class
Ammo (rounds)
Range -2%
Max Speed +5%
Stall Speed -5%
Slots Required 3 Engine slot(s)
Price: 50000Ģ
Availability: Fuseli, Earthbreach, Arcadia

Despite the description, a combination of R Sticker and Port and Polish offers more speed and less range reduction for almost every plane; however this upgrade remains an effective way to lower stall speed on some of the high tier Performance planes.

Combat Festival Candle · Increased Ammo · Mad Props · Mega Ammo · Shiny Red Light · Sleigh Bell · Super Ammo
Engine 4 Barrel Carburetor · 6 Barrel Carburetor · Boring Out · Coolant System · Efficiency Mod · High Efficiency Mod · High-Flow Air Filter · Internal Air Diversion Plates · Internal Fuel Can · Internal Fuel Tank · Larger Props · Port and Polish · R Sticker · Super Charger · Turbo Charger
Hull Additional Cargo Hold · Gutted Cargo Hold · Gutted Craft · Heavy Armor Plating · Internal Fuel Expansion · Large Internal Fuel Expansion · Light Armor Plating · Lightweight Shell · Med Armor Plating · Steel Reinforced Hull · Streamlined Hull · Wood Reinforced Hull
Wing Drop Tanks · High-Lift Wings · High-Performance Wings · Improved Wings · Large External Cargo Hold · Large External Fuel Tank · Med External Cargo Hold · Med External Fuel Tank · Small External Cargo Hold