Driven pitted a 2012 Pentastar Wrangler Renegade Unlimited four-door automatic against a 2010 two-door with the old 3.8-litre motor.
The newcomer's a couple of seconds quicker from start to 100km/h and has shorter overtaking times, but was far from leaving the older Jeep in a cloud of dust.
Maybe that's just as well because, despite a well-refined coil-sprung beam axle suspension, the Wrangler Unlimited's handling is kind of vague and floaty at higher speeds. A sports car it isn't.
So this might have been another "new engine, so what" sort of article, but the Pentastar has one huge redeeming feature - its fuel consumption is outstanding compared with the unit it replaces.
Designed more than 20 years ago, primarily for the American market where fuel prices were, and still are, cheap compared with what we pay, squeezing kilometres from each litre was never a strong point of the 3.8. That 2010 model, which is smaller and lighter than the Unlimited, typically uses between 15 and 17 litres per 100km, depending on the driving.
In several days over the same roads, the Pentastar Wrangler consumed around three litres per 100km less. Off-roading in the SUV's spiritual home, the Jeep Woodhill 4WD Adventure Park northwest of Auckland, the Pentastar wouldn't do worse than 16.5 litres per 100km in the fuel-sucking low-range. The 3.8 would be pushing 20 on similar tracks.
True, owners of economical cars getting five or six litres per 100km will be appalled at the Pentastar's thirst, but I reckon being able to enjoy the Wrangler's considerable fun factor and having to pump that much less petrol is something to be pleased about.
The Pentastar, also rolled out locally in the Grand Cherokee Laredo and Dodge Journey, can't take all the credit.
It's mated to a new-to-Wrangler five-speed automatic with a tiptronic-type manual sequential shift for those who like more control over their driving.
The outgoing Wrangler V6 used a four-speed not designed with economy as a priority and it lacked various fuel-saving tricks of the new unit.
Although a manual is still available, Jeep's only bringing Wrangler in for stock with the autobox. With this new transmission, there's not much point to the manual, anyway.
Best thing about the new engine is prices have not moved, so at $56,990, the Wrangler Renegade is not only better value, but a bit cheaper to run.
For the purist
If you want to experience Jeep's true off-road heritage, go for the Rubicon model, not the Renegade, which is more about show than go.
The Rubicon has front- and rear-locking differentials, a front swaybar disconnect to improve axle articulation, much lower gearing in its transfer case, and some smaller trail-friendly differences.
Even out of the box, the Rubicon's an off-road weapon; throw a few thousand dollars worth of well-chosen modifications and there's little that can touch it this side of a custom-built rig.
The bottom line:
It's business more or less as usual, until you look at the fuel consumption.
