I have an '09 GT, five speed.
A friend told me that I should put in an aftermarket air filter to slightly increase the HP. Is this a good idea? Why wouldn't Ford put in better air filters themselves, since they could market the car as having 305 HP instead of 300HP?
What is the best strategy to accelerate quickly from a stop (e.g., at a stoplight)? Do I shift for each gear only when it is near the redline? I assume that is the case, but it feels like I don't get much acceleration out of first gear. Any other tips or techniques?