The Skybrary
High Efficiency Mod
Upgrade Category: Engine Upgrades
Even better, and more expensive, than the original Efficiency Mod.
Armor (mm)
Armor Class
Ammo (rounds)
Range +10%
Max Speed
Stall Speed
Acceleration -10%
Slots Required 4 Engine slot(s)
Price: 300,000Ģ
Availability: Olio, Alpha 10, Alpha 13

Superior to the Efficiency Mod so long as you have the money and engine slots to make use of it.

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