This engine has a few quirks, like the start-up noise. I was idling at the trailhead for Hell´s Revenge in Moab and a guy with a JK and gen 1 Pentastar asked if mine was a diesel, LOL. The slight diesel-like racket it was making hadn´t grabbed my attention until then, but I could see how he thought that. Maybe it was the 0w20 and the cool morning? Who knows? But I do love this engine.
I took another off-roading mini-overlanding trip last weekend in my JLUR. So the trip included 4 hours of highway driving, some curvy state roads, and 100 miles of a combo of country roads, trails, gravel roads, water crossings, deep mud holes, and technical rock crawling, including the single toughest obstacle I´ve attempted in my Jeep. It was one that I thought would take it right to its absolute extreme limit of capability. (I was wrong, as it easily handled it once I was coached by a couple of VERY experienced Jeep club leaders). This engine cannot fully be appreciated until you run it through this kind of wide range of use.
What just impresses so much is how well it behaves in each situation. Every adventure I take in this Jeep convinces me more and more that it is all around, the best possible compromise for a Jeep that I´ve ever experienced, and I´ve experienced pretty much all of the Wrangler powerplants over the years. All (except maybe the 3.8 in the JK) perform exceptionally well in certain areas, and fall short in others. (The 3.8 is underwhelming, but adequate. It doesn´t shine in any area, but isn´t a complete turd, either. It is just meh, but has been 100% reliable for me through 142k miles.)
On the highway, this Jeep/Pentastar combo can get over 20mpg with 35¨ tires if I stay at 65mph. It drops off to about 18 at 70, but still behaves well and has plenty of power, and is quiet and very smooth. It is easily the most efficient and best behaved Jeep engine I´ve driven or experienced on the highway. It can run all day at 90mph, too, if anyone with a Jeep cared to do so.
On twisty state roads and country roads, this thing is just a joy. It loves to rev, and the harder it is pushed, the more fun it is. I love to come off corners in the right gear and accelerate out of them right up to redline. With a Magnaflow axle-back exhaust, it just sounds and feels great, to me. It pulls strongly all through the power band and does not run out of breath at high rpm. In fact, at about 4500 you feel a real kick in the pants, which I´m assuming Is due to valve timing changing, which pulls hard all the way to redline. Love it. In fact, I just can´t keep my foot out of it, so I do this all the time. It feels tight and smooth and sounds and pulls great, all through the high rpm range. It loves to rev up there and feels like it could stay there all day. It is really in its element there.
On the technical stuff, when Jeep 4.0 inline 6 and even V8 drivers think the Pentastar will choke on a lack of torque, it proves them wrong again. It effortlessly (in combination with the excellent gearing of the Rubicon, with 4.10 axles and an 84:1 crawl ratio in 1st gear low) pulls the Jeep through anything from thick, deep, gumbo mud to very slow technical rocks to steep inclines. It does this with such smoothness and quietness that several times my son commented that the engine didn´t feel or sound like it was even running. Oh, did I mention it did this with the air conditioning on the whole time. In Moab, skeptical 4.0 TJ drivers watched it go up steep 30 degree inclines not realizing I was idling with my foot not touching the gas, the whole way up, and again, with the air on keeping us nice and cool and comfy the whole way. (And dust free thanks to the cabin filter. It really feels like this Jeep is cheating.)
The great fun is when the 4.0 guys start talking torque and the Pentastars alleged lack thereof. Then you show them the dyno charts and they realize that other than right off idle, the Pentastar has more than the 4.0 pretty much through 90 or so percent of the powerband. It gets 90% of its peak torque around 1500rpm. What they don´t understand is that this engine is pushing around a MUCH heavier Jeep than their YJs or TJs. Put that Pentastar in a YJ or TJ and you´ll have a real beast and I guarantee you won´t hear a peep about torque. But I digress....
Anyway, the more I live with this engine, the more impressive it really is. And btw, I see the gen 1 Pentastars in Jeeps with 200k to 300k miles all the time. A few are beyond 300k and run like new. Because I see them with the Jeep clubs, I know many of them have been run in not so optimal conditions. Some have been almost neglected. I have yet to run into a club member with a Pentastar who doesn´t love it and praise it. Some don´t know much about it at all, but praise it nonetheless.
So back to the topic of the thread. It does have a couple of quirks.
@OIL_UDDER and I have been talking about some of them, including how for oil changes, if you drain it for many hours and come back, you´ll still see oil dripping or trickling out due to the complexity of the valve train. It also has the weird habit of twisting its cartridge oil filters. The start rattle is a big one. But once warmed up, it is a sweet powerplant. In fact, from the cockpit of the JL, it is so smooth and quiet, several times I´ve thought it was off and stalled it as I let the clutch out while in gear. (I always have foot on brake in that scenario, so it hasn´t gotten away from me. I usually curse myself for forgetting. The start/stop button is the culprit here, really, after a lifetime of habit from having a key to shut off.) It is the favorite of all the engines I´ve owned, and I´ve owned some world class ones, such as the 4.3 V8 in my Mercedes E430. I might also mention the Pentastar has been on Wards 10 best in the world engine list multiple times, including last year with the mild hybrid version from the Ram. I´ll also mention its versatility, from the Challenger to the Promaster commercial van, to the Ram to the luxury/sport Chrysler 300, to the mini-vans to the Wrangler. It seems to shine in each and every one of these diverse applications. As better transmissions have come along, the engine´s strong points have shined even more. Only a truly great engine could do that. That´s why there are more than 11 million of them on the road and the end is nowhere in sight.
I will note that it doesn´t hurt that my Pentastar is the PUG model with about 14% more torque at lower RPM than the Gen 1, and it has a wonderful match with the Aisin 6 speed manual transmission and the JL chassis, which is, IMHO, the best Wrangler yet, by a wide margin, on and off the road. Those things certainly make it easier for the PUG to impress. I plan on keeping mine for decades, and fully expect it to be trouble-free. It has been perfect for the first 34k miles, so it is off to a good start, cold rattle, and all.
