There's an old car-guy adage that claims there's "no replacement for displacement."

Yet tightening global emissions standards are forcing carmakers to find a variety of replacements, as they plan to shrink the sizes of engines across their lineups in the name of fuel economy--without sacrificing the performance customers are used to.

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For Ford, that's meant extensive use of turbocharged and direct-injected EcoBoost engines. Now it appears Chrysler could follow suit with its own Pentastar V-6 engine.

The carmaker will add turbochargers and direct injection to the Pentastar to improve its efficiency, according to a recent report from Automotive News (subscription required).

2014 Jeep Grand Cherokee

2014 Jeep Grand Cherokee

This Pentastar Upgrade--called PUG, for short--would improve fuel economy in an engine that's currently used throughout the Chrysler realm in naturally-aspirated form, and possibly boost power as well.

The first upgraded engine iteration will reportedly launch in the Jeep Grand Cherokee in late 2015 as part of a refresh of that model.

The current-generation Pentastar also launched on the Grand Cherokee--back in 2010--and initial versions of the upgraded engine are expected to maintain the 3.6-liter displacement it's had so far.

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However, Chrysler may also use a new 3.2-liter version in the next Town & Country minivan--which is due in 2016.

That engine will be combined with Chrysler's recently-introduced nine-speed automatic transmission to--along with weight reduction and aerodynamic improvements--increase fuel efficiency by 25 percent.

Tangentially, a plug-in hybrid version of the Town & Country is expected next year--which would seem to put it ahead of the rest of the redesigned lineup.

2015 Chrysler Town & Country

2015 Chrysler Town & Country

The "PUG" V-6 could also be used in the Ram 1500 pickup to further broaden its range of smaller-displacement engines.

Ford offers 2.7-liter and 3.5-liter EcoBoost V-6s in the 2015 F-150, while Ram offers the naturally-aspirated 3.6-liter Pentastar V-6 and the 3.0-liter EcoDiesel turbo.

MORE: 2015 Pickup Truck Fuel Economy: Ford Vs Ram Vs Chevy, Who's Best?

The smaller Ford engine beats the Pentastar in fuel economy, but the EcoDiesel tops both of them; it's the most fuel-efficient engine currently offered in a full-size truck.

In addition to fending off the competition, Chrysler will have to meet increasingly-strict U.S. Corporate Average Fuel Economy (CAFE) standards--all the more reason to squeeze every last ounce of efficiency from a given amount of displacement.

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