Ford Focus Forum banner
81 - 84 of 84 Posts

·
Registered
Joined
·
389 Posts
When a car is "tuned" several aspects of the factory settings are changed. Timing advance or retard is one of them.
The car is not "tuned" specifically for 87 octane. The stock ECU is able to advance and retard timing as octane increases and decreases, with a minimum spec of 87 octane. Don't believe me? Hook up an OBD-II logger to your car, put in high octane (or even better e85) and watch the magic.

BTW, I understand what a tune is. To say that the Ti-VCT is tuned specifically for 87 octane is simply incorrect. For that matter, it would be incorrect to say the same for any engine that is able to adjust spark timing, or intake and exhaust valve timing due to changes in octane. If that were the case, then there would be no horsepower advantage at all for using a higher octane fuel (such as E85) with the stock programming. Can it be tuned to have more aggressive timing advance at higher octanes, and require a higher minimum? Of course it can.

Now, if you were to say that it is tuned stock for a minimum octane of 87, that would be correct.
 

·
Registered
Joined
·
883 Posts
Discussion Starter · #84 ·
I contacted roush to see what they would say. Hopefully they won't be like everyone else and focus only on the ST.
 
81 - 84 of 84 Posts
Top