Advice From Rossler's site - I have aked him many times same answer for TF's

Synthetics are Acceptable but Not Required.



900 HP OR LESS - Recommended Fluids



Dexron3/Mercon



Racing Fluid (B & M or TCI)



Ford- Type F



50/50 Mix of Dexron 3/Mercon and Ford – Type F



900 -1,500HP - Recommended Fluids



Racing Fluid (B & M or TCI)



Ford- Type F



50/50 Mix of Dexron 3/Mercon and Ford – Type F



1,500HP and up - Recommended Fluids



Specialty Racing Fluid



Racing Fluid (B&M or TCI)

Hydraulic Oil (10W-20 or 30 Weight)



10-20 or 30 weight synthetic fluid acceptable on all level horsepower the heavier weight fluid the better lubrication to gears and components you must use a slightly higher viscosity fluid to equal lubrication value of conventional non synthetic fluid. The less horsepower you have the lighter viscosity fluid you can use as horsepower increases so should the viscosity of the fluid. Although some turbo powered cars and cars equipped with lock up torque converters need the thinner fluid for spooling and stall speed adjustment purposes. Unfortunately this is a necessary evil that can shorten the life of the transmission planetary gears.