LOL >>
These two graphs speak volumes. If you logically think about K&N's premise: increase Horse Power by increasing air flow. The less restrictive the
air filter, the greater the air flow. Unfortunately, more debris will be passing through the
air filter (as shown above), into the
intake manifold, then into the cylinders. Even if no cars are ever damaged running K&N air filters, is the cost of the filter, filter oil, filter cleaner, and required maintenance of these filters require, worth K&N's claim of 1-4 Horse Power increase?
Most of us are probably changing the
air filter prematurely. An interesting report by the EPA on clogged air filters and the impact on MPG, concluded:
"Closed-loop control in modern fuel injected vehicle applications is sophisticated enough to keep a clogged
air filter from affecting the vehicle fuel economy."
LINKto the EPA study (2-2009).
The factory engine is a balanced system (a compromise of performance, reliability, and efficiency).
Air filter all the way to the exhaust, don't forget the programming. Add a K&N filter, the system is unbalanced. To maximize the potential, additional air flow increase K&N can offer, one would have to change out many other parts;
exhaust system for sure, as the stock exhaust is very restrictive compared to a "performance/racing"
exhaust systems.
Formula 1,
Nascar, and Rally cars, are probably using K&N or something comparable. But those aren't normal everyday engines. Those
bad boys are built from the ground up around performance, and cost a pretty penny. Penny is an understatement. I was off by many factors, when I searched "cost of formula 1 engine." 2014 F1 engine: average price $7.7MILLION (I'm assuming USD, as no currency unit is stated).
LINK
You are driving a Prius. Not a sexy car, nor a fast car. But sexy MPG.