This is a little bit of old news to our Facebook and Instagram followers, but about a week go we installed an AFE Power cold air intake.
Normally, we are not fans of CAIs, especially with the Pentastar engines. We know several people that have pretty severe oil consumption after running their JK/JKU (3.6L) in dusty environments. Sadly, many ultimately needed a new engine to resolve and the fault was put on the CAI they ran. Even the Mopar branded intakes did not shield the warranty denials. Compound this with the fact that we tend to believe all those power gains felt are a placebo effect from spending money and not wanting to admit it was a waste of it. After all, if it were that easy why wouldn’t the manufacturer do it?
As stubborn and opinionated as we are, we still listen and keep open minds. So, when so many people over at The Jeep Cherokee Club mentioned not only felt performance gains, but also increases in fuel economy (something we have struggled with), we thought it made sense to give it a try.
To make a long story short, Jay and I can’t believe the difference the intake has made. We have noticed fairly significant throttle response improvements and while it’s a little too early to tell for sure, we think our average MPG has jumped by about 2! These aren’t the only gains though, the little 3.2L sounds pretty amazing! We had no idea she had such a pretty voice 😛
The changes are literally so drastic, it got me wondering why? After all, even AFE only advertises a 9HP/10lb-ft increase. It’s hard to imagine this change on top of the 3.2L’s 271HP/239lb-ft stock specification would change the vehicle’s performance so drastically.
The only real answer I have is where the power is added…. See the dyno chart below.
The 3.2L Pentastar has a VERY steep HP and torque ramp in the 2,000 – 2,400 RPM range. After this, the torque is very flat and the HP follows a nice (and far shallower) ramp. The thing is, the ZF9 transmission that the KL Cherokee uses keeps the engine in this very low RPM range where even the slightest wind, hill, or load change forces a drop in gear, or even multiple gears, for the engine to find enough power to handle it.
This is just my opinion, but since the largest gains the CAI provides seems to be right in this area, it makes for a fairly drastic drivability improvement. There are small grades that Klondike used to downshift for where she now easily holds onto the current gear.
So, all-in-all, we are extremely happy with this mod and recommend it to just about any 3.2L KL owner.
In the spirit of full disclosure, AFE needs to reevaluate the hole location for the air temp sensor. Ours barely reached the hole they provide and this was after removing some tape that held it to another harness which allowed for more direct routing. Also, notice the sharp increase the AFE intake provides at ~2200 RPM… This is felt when driving. It almost feels like the engine hits a “power band” like a 2-stroke 😛 . From this point until about 2600 RPM is also where the largest sound change is, so it’s hard not to step into it a bit for the sound. In any case, it does take a little getting used to when putting around town. 🙂