Balancing Act

Fuel economy: Injen CAI versus OEM air box

I've recently removed my Injen cold air intake system (CAI) and noticed a drastic increase in fuel economy.

Mind you, with the OEM air box back in, no more VTEC roar at 5.5k RPM or audible air suction sound. Matter of fact, you can't hear VTEC engagement at all unless you turn off the stereo and listen really carefully for it! That's not the interesting part. The observation that caught my attention is the fuel economy. And it appears to have been increased with the OEM air box back in place. Increased drastically. I'm currently at half tank without the Injen CAI and the trip meter reads 200 miles. This is combined city and highway driving. At half tank with the Injen CAI, I usually clock in at around 140-150 miles. So to validate my observation, I'm going to run a couple of tests. I probably won't have results for another 4-5 weeks after doing 3 full tank to empty tank trial runs.

PS - If anybody wants, I'm selling my used Type-S specific 02-06 Injen cold air intake for $175.00 shipped (48 contiguous states). All hardware and a Hydro Shield is included. It has been on the car for a little over a year.

3 thoughts on “Fuel economy: Injen CAI versus OEM air box

  1. Greg

    Hey I found your page after coming across your taillight mod on YouTube (nice!). I just got an '05 RSX-S and was planning on getting a cold air intake for it. I too with stock air box was at 200mi at half a tank. I just got 28.5mpg mixed driving on my first 3/4 tank. So, did you lose power replacing the stock air box? I'd be interested in your Injen CAI for somethin like $100 or maybe $125. Let me know what you think

    1. Steve Post author

      Still testing the results; stock airbox = lost of power, there's no doubt about it. I'm back on the CAI again and the fuel economy result is mixed. Not sure if the weather played a factor, but the results are not consistent enough (yet). Still need to run a few more long distance run before I can conclude my findings :).

      1. Greg

        Alright, coo'. Seems about right -- gaining power at the loss of fuel economy. It's kinda hard to have the power and go back to not, I'd bet. I am looking to get a CAI, so let me know what you end up doing, and if you'd recommend the Injen one over AEM, and what you might think about getting a cheap off-brand one but getting a name brand filter. Thanks

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