2010 mazdaspeed3 HP
 

i bought one of these in feb, the dealer sticker says 263hp. while sufing on the web i see all these dino's whith about 240 hp. what does the car come with, 240 or 263??? im looking to get the K&N and it say 24 hp gain to bring me to 264 on there base dinos. whos full of it??? anybody else wondering this as well???

the dealer's posting of 263hp is flywheel hp which is what all manufacturer's use. flywheel hp is measured directly at the engine. when the car is on the dyno the hp is measured at the wheels so there will be a loss typically 10-15% at least so that's why it says 240hp on your internet search.

i doubt k&n would give 24hp at the wheels but maybe that number is measured at the flywheel. the only way to know how much difference it makes for sure is to dyno your car without it and then again after installing it. i'm no expert but most well-designed cold air intakes on a forced induction car will give about 5-15whp depending on post-tuning so you can use that as a rough guide or ask some other owners who have done this mod and dyno'd the car after.

2010s have the same engine/drivetrain/horsepower as the 1st gen MS3, but they weigh about 100 more pounds.

I agree with binz. k&n is full of it. :) 24hp? Sure, just add a Cobb Accessport and a wide open exhaust.