Here is one of the best descriptions I could find on the replacement coils:
SMOK TFV8 Turbo Engine Coils Features:
Patented Turbo Engines Coil Structure
V8-T10 Deca/Decuple Coil
Patented Deca/Decuple Coil Design
Kanthal Clapton Coil Material
Turbo: 10T
0.12ohm rated for 50~300W, recommended 130~190W
V8-T8 Octuple Coil
Patented Octuple Coil Design
Turbo: 6.6T
0.15ohm rated for 50~260W, recommended 120~180W
V8-T6 Sextuple Coil
Patented Sextuple Coil Design
Turbo: 6.0T
0.2ohm rated for 50~240W, recommended 110~150W
V8-Q4 Quadruple Coil
Patented Quadruple Coil Design
Turbo: 5.0T
0.15ohm rated for 50~180W, recommended 90~150W
V8-X4 Quadruple Coil
Double-Barrel Pistol Design
CF Mate (Cloud & Flavor Balance Core)
Turbo: 4.0T-X
0.15ohm rated 60~150W, recommended 80~120W
V8 RBA Head
18mm Build Deck
Two-Post, Dual Terminal Design
Turbo: 4.0T-X
0.28ohm Fused Clapton Dual Coil rated for 50~140W
V8 RBA-16 Head
18mm Build Deck
Two-Post, Clamp-Style Mechanism
Turbo: 5.0T-X
0.16ohm Fused Clapton Octuplet Coil rated for 40~100W
They make a ton of these things and other companies also make coils that are compatible. Higher resistances will give you better battery life but possibly less vapor production. Flavor is hit and miss and the best way to know is try a few.
Good luck!!