K&N 66 vs. 77 Series vs. Sixth Element CAI: Which Did You Choose and Why?

rustytaco · 2026-04-30T07:05:46+00:00

Decided to make the switch to premium fuel to see what would happen... For reference, I also have the hybrid. I've heard that making the switch isn't simply something you feel from one tank, but rather several as your truck adapts to a higher octane. I was skeptical, and I could always be imagining it, but I swear it feels like it has more get up and go. And even better, it seems that the MPGs have improved, at least around town on an average commute of 20ish miles. Given how built my truck is, lots of added weight and reduced aerodynamics, my hybrid already did pretty good. I average about 16-17 mpg with no problem and a good commute could get up to 20 or so. With the premium gas, the good commute average went up closer to 21 mpg. Granted, this is me trying to see how good I can get it, without any crazy throttle input. Quick screenshot below of my dash readings. This is an average after a day of driving after a reset. And this has to be adjusted 10%, which comes out to 20 mpg. Anyone else tried it? Let me know what you experienced, if anything. Obviously, there are a lot of factors here. Toyota tunes these trucks with premium gas, so this is likely part of the equation. Using what the truck was designed for. Premium is also better for the longevity of any turbo motor. Next up, I'll be adding a Cobb Accessport with a custom OTT tune from Big Dawgs Toyota Tuning. Lots more to come there... A quick shot of the truck as it sits now.

TrdMarkey

Member

Aug 6, 2025

#1

Those who have K&N CAIs, did you go with the 66 series or the 77 series, and why? They seem very similar, except the 77 series appears much easier to install. I’m also considering the Sixth Element CAI. Would love to hear what others think about each of them.

Just a heads-up, though: as someone who went down the CAI rabbit hole in my early years, you only reap the benefits of these if you also get a tune to adjust various ECT parameters for the different airflow.

Without a tune, aftermarket intakes can actually hurt performance more often than help. One of the reasons why I'm still weighing my options before making any decision.

You must log in or register to reply here.