201? Jeep Cherokee Diesel

2012 Jeep Grand Cherokee (Gasoline Model Shown)

By Thom Cannell
Senior Editor
Detroit Bureau
The Auto Channel

Detroit January 10, 2012; Last week Chrysler dropped a bomb on diesel enthusiasts announcing it would bring back diesel power to the Jeep Grand Cherokee, and that was all they would tell The Auto Channel other than it would be built at the Jefferson North facility in Detroit. A bit of sleuthing at the Detroit show and on international web sites made the proposition much clearer.

In January 2011, VM Motori (a joint venture between Fiat and GM) launched its latest diesel engine, the A630 3.0L V6. Power output is listed as 410 lb·ft and 245 horsepower. Fiat Powertrain Technologies contributed its Multijet2 technology for improved performance, fuel economy and NVH. VM Motori’s website lists the first application of the 3.0L V6 as the European 2011MY Grand Cherokee. We cannot imagine that Chrysler will expend engineering resources for a different power train, only spend the necessary coin for a US specification aftertreatment system as current Euro 5 regulations are much less stringent on Nitrous Oxide (NOx) emissions than the US. A low 16.5:1 compression ratio confirms this.

The engine is among VM Motori’s newer engines and uses a compressed graphite iron block, chain-driven double overhead camshaft and four valves per cylinder, each driven by efficient finger followers. Injectors, piezoelectric, provide up to eight injections per cycle for great fuel efficiency and very quiet operation. The turbocharged engine uses cooled EGR to improve emissions and fuel economy.

We also expect that the US version may continue with the five-speed automatic transmission used in Europe, it’s good enough for the scalding SRT8 with greater power output. Lurking in the background is a possible shift to the new eight-speed transmission Chrysler developed in cooperation with ZF. At introduction that transmission will fit lower power V-6 applications and no high-torque applications have been announced.

Performance and economy should be similar, despite a slightly more restrictive aftertreatment system, with 8.2 second 0-62 miles per hour acceleration and 126 mph top speed. Using European measure and Euro 5 standards, the diesel Grand Cherokee achieves city consumption of 27.4 mpg, highway (extra urban) 39.2 mpg, and combined 34 miles per gallon. We also expect tow capacity to be similar to the European version, which says it will tow up to 3,500 pound braked trailers.

This the kind of news we, and diesel fans everywhere, have awaited. With GM’s promise to bring a small diesel, Mazda’s SKYACTIV diesel, and more diesels from Mercedes the trickle of diesel engines appears set to become at least a modest stream.