Snake oil sold everywhere. Even if one attempts to be a wiser shopper it can be easy to be caught up in a snake oil trick.
A few years ago after I bought my Hyundai Elantra, I was into the idea of tweaking it with a CAI. Read how I'd get oh maybe 10hp. Meh it was just under $200 US shipped. I know Elantras are not hi-po sports cars but hey, if I could get a bit of a performance tweak it would be an easy $200 thing to do. Especially moving from my then cool and faster Daytona Shelby Z which I miss dearly today!
I had the CAI on within 2 weeks of buying the car and I had little feel of how the car really drove in day to day living before bolting on my CAI. I put it on and upon start up the added growl caught my attention and as I began life with the CAI. I believed I was getting more OOMPH! Under good throttle the car growled nicely and it felt like I was getting some get up and go. It did feel as if I really was getting a snappier throttle response. So it all felt good (my butt dyno was happy )
Well a week ago or so I pulled it out and put the stock set up back in. I may be selling the Elantra soon and figure to sell it in stock condition.
BUT! what I soon found out was the following.
Driving around with the stock air box back in I noticed the car was obviously quieter. But it actually has more bottom end once you get past the ever so slightly slower throttle snap. I found that in comparison to the last few years with the CAI I have more torque and a smoother acceleration between especially 2000-3000rpm where as I now realize the CAI gave me a bit of a flat power spot in that rev range. Yes, maybe at the top end of revs in WOT that CAI may have felt a bit more stronger (I doubt it much though) but in reality it was SNAKE OIL! The added growl with a bit of a snappier throttle off idle had me BELIEVE the CAI as a simple bolt on was making my car faster.
Well since then I have been reading up on forums and watching YOUTUBE vids to see that CAI or ram filters or even K&N drop ins are really just BULL SHIT, SNAKE OIL if one only does as a simple bolt on or drop in. Of course many on line like I use to be, using only our butt dynos believe these give more performance and even better fuel economy. But I now know better that they only do one thing well, TAKE MONEY FROM YOUR WALLET!
Of course one can get added after market performance to most any car, but it's not just a simple drop in K&N air filter or bolt on CAI or ram filter. It requires moving air in well, combusting it well and moving the exhaust out well.
CAI + Pro ecu tuning + freerer flowing exhaust + maybe bigger fuel injectors can yield real power gains. I bet after such one can see 10-15-20-25% more power typically. So maybe if I spend $1000-$1500-$2000 to do all this on my Elantra I can go from maybe 140 bhp stock to maybe 160-165-170 bhp or so. But I'd still have just a nice car but still meh an Elantra, not a Porcshe, Viper, Camaro, Challenger,Vette, RX-7, Supra, Mustang, or BMW M3 etc.
Like one poster on a forum I read noted. "If you want a faster car, BUY A FASTER CAR!"
I could tomorrow get 90+ bhp more power for about $1,500 plus selling my Elantra and get a faster and even cooler car without getting may hands dirty and without having to shop around, order and wait to install parts that on my Elantra may only get me 20 or so more bhp.
CAI, ram filter, K&N drop ins are SNAKE OIL as real performance upgrades, if that is all one does to their car. You may likely get lesser real world performance and lesser fuel economy by adding such and just PISS YOUR MONEY AWAY!
Hyundai engineers (in my case) know their engines and designed in my case the 2.0L 4 banger to give best power, driveability, quietness and fuel economy. Some small shops peddling CAI, ram filters or even the mighty K&N marketers with their drop in filters do not know the engine better.
SAVE YOUR MONEY GUYS! Unless you want to do a front to back tuning of your car's induction, fuel, spark, ecu tuning and exhaust.
BUY A FASTER CAR IF MORE STRAIGHT LINE SPEED IS WHAT YOU WANT!
That said their are things one can do to get better all around performance. First, buy better tires. That alone will gain you better driveability, ride and cornering power. Buy better brakes and maybe improve your suspension. These things ARE NOT SNAKE OIL!