All my friends put 98 octane into tank.
but i am thinking about if it worth?
95 and 98 are big different?
Can I fill 95 every day,and 98 in a track day?
thankx

 

Turbo?


-Ted

 

if you've allready used 95 and it works fine, and you don't change anything on the car.. keep using it! Why bother with a higher octane fuel that your car does not need.

If the car is modified, running higher than stock boost levels, etc, then a higher than stock octane requirement will be there, and you'll need to use better gasoline.
If the car is just stock though, TII's (at least s4 TII's) require only 87 octane on our scale (91 RON minimum)

 

TII's generally run a higher octane than the N/A's. All you really need for an N/A is 87 octane.

 

For stock and near stock FCs you will only loose HP using anything above 87 octane, and basicly throw your money away, as well as clog the engine up with un-burnt fuel. You want the fuel to start burning and burn completly and for a long time for the most power on a rotary. Higher octanes by their basic design are designed to resist burning until the last possible millisecond then burst.

A modified Turbo model with higher than stock boost would be only reason to use anything higher than the lowest grade octane and then only to help stock against pre-ignition of the fuel.