2009 Jeep Wrangler Unlimited Rubicon on 2040-cars

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FCA's Pentastar V6 gets more power, efficiency for 2016

Already a vital member of FCA's powertrain lineup, the 3.6-liter Pentastar V6 is receiving major efficiency improvements for 2016. Thanks to a massive amount of new tech attached to the mill, fuel economy is up six percent, and torque below 3,000 rpm jumps nearly 15 percent. The updates arrive first in the 2016 Jeep Grand Cherokee, but they should proliferate to other models eventually. At least in the Grand Cherokee, the tweaks push power up five horsepower to 295 ponies. FCA's engineers went through the Pentastar from top to bottom to eke out as much efficiency as possible. For example, there's now a two-speed variable-valve lift system that can run in low- or high-lift modes. This upgrade is responsible for 2.7-percent better economy, the company claims. A new intake manifold with longer runners and updated variable-valve times also helps boost the torque output. Further improvements come from pushing the compression ratio to 11.3:1, from 10.2:1 before. Perhaps most impressive is that despite all of the innovations, the latest Pentastar actually weighs four pounds less than the current version. Beyond the Pentastar improvements, all of the FCA US gasoline engines, except for the Viper's 8.4-liter V10, will be E15-compatible for 2016. The company says that it wants to be ready for the higher ethanol content fuel's greater use in the near future.

Watch this 650-hp Hennessey Jeep Grand Cherokee go from 0-60 in 3.9 seconds

Hennessey Performance Engineering has created an HPE650 package for the Jeep Grand Cherokee SRT fitted with the 6.4-liter Hemi engine. When it leaves the showroom floor it has 470 horsepower and gets from 0-60 miles per hour in 4.8 seconds. When it leaves Hennessey's garage floor after the upgrade it has 650 horsepower - 530 hp at the wheels, according to Hennessey - and gets to 60 mph in 3.9 seconds on its way to running the quarter-mile in 12.6 seconds.
There's more than just a Roots-type supercharger bolt-on, with ported cylinder heads and high-flow headers among the many changes made to the engine. You can watch this pre-2014 facelift silver model prove its spec sheet on the drag strip in the video below.

NHTSA closes investigation on 4.7M FCA power modules, no recall

FCA US hasn't had the best time with recalls as of late. Not only did the company recently agree to greater safety oversight and paid $105 million to the government, that came just days after hacking fears prompted a 1.4-million model recall campaign. However, a recent decision to close an investigation by the National Highway Traffic Safety Administration means that the automaker doesn't have to worry about another major recall possibly affecting 4.7 million vehicles, according to the agency's report (as a PDF). Last September, the Center for Auto Safety petitioned NHTSA to investigate an alleged problem with the totally integrated power module (TIPM) on these FCA US models. The group claimed that a fault with the component could cause a variety of maladies, including stalls, not starting, catching fire, unintended acceleration, and airbag non-deployment. At the time, it also submitted 70 cases where this had reportedly happened. According to NHTSA, "no valid evidence was presented in support of claims related to airbag non-deployment, unintended acceleration, or fire resulting from TIPM faults and these claims were found to be wholly without merit based on review of the field data and design of the relevant systems and components." The agency did find signs of an issue with the fuel pump relay in some Jeep Grand Cherokees and Dodge Durangos, but FCA US issued recalls for the problem in September 2014 and February 2015. Without anything else to go on, the Feds don't think it's worth investigating this topic any more.