Anti_AhSiah SG Usually, tuners toy with parameters such as ignition timing, air/fuel ratio with the appropriate mods such as larger XOS related pipings, better air intake, larger turbo etc. Cheers.
nOrmalbOi SG While I noe that there are many parameters to fiddle with, most of the numbers and technical jargon spouted by the tuner is greek to me..
tailslide SG hard to say. this is generally the case if there has been significant other mods done prior to the ecu tune up. i noticed that for cars that has close to stock configuration (air filter/exos change) experience slightly better FC in addition to a slight power bump over the stock mapping, mainly because the stock mappings tend to run rich as a safe guard. the only exception is turbocharged applications, where even slight improvements in the engine's breathing capabilities can result in significant increase in FC as a result of the injectors working overtime.
