2007 Dodge Ram 3500 6.7L Cummins Bluetec - First Drive

Toyota Prius owners move over, there's a new environmentally friendly vehicle on the roads-and it's one you can actually be proud to drive: the '07 Dodge Ram 6.7L Cummins Bluetec. Believe it or not, this clean diesel makes 350 hp and 650 lb-ft of torque in stock form, is quieter than ever, and already meets the strict EPA emissions rules that don't take effect until 2010.

New Cummins 6.7L BluetecIn addition to a larger bore and a longer stroke to help ensure fuel is completely burned, the newest version of the Cummins ISB uses a large exhaust gas cooler with a fast-acting Siemens EGR throttle. Spent gases are chilled and then sent to the new intake throttle that allows the engine computer to mix and match air/fuel ratios so the exhaust that passes through the oxidation catalyst, NOX storing catalyst, and particulate (soot) filter comes out 50-state legal, earning it the Bluetec label, which will also be slapped on some German cars headed to our shores.

Of course, the Ram passes a standard that applies only to the 8,600-plus-pound GVWR 31/44- and 1-ton classes of vehicles, but this Cummins blasts past the new '07 EPA emissions standards and meets the '10 regulations without the use of a complicated urea injection system that may show up in some lighter cars and trucks over the next few years. The relative simplicity of the Cummins Bluetec system is one of its greatest assets. Any performance lost to the EGR and DPF cannot be felt because the new variable turbo and engine programming make the 6.7L more responsive and powerful than any stock 5.9L. Unlike the new 6.4L Power Stroke, soot burn cycles are relatively unnoticeable, with the engine rpm idling just 100 or 200 rpm higher than normal. Throttle response is immediate, with fueling that begins as soon as the pedal moves, and there's no electronic-induced lag time.

Variable Turbo with Exhaust BrakeThe Holset VGT with a built-in exhaust brake is listed on the window sticker as a no-cost option worth $500, which means everyone who orders a truck with the 6.7L gets one for free. It's a nice touch and very handy during towing, but the new variable-nozzle turbo should be getting the headlines. Instead of using pivoting vanes like the Duramax or an electronic actuator requiring coolant like the dual-turbo Power Stroke, the Cummins turbo uses fixed vanes that slide into the path of the exhaust at low engine rpm. Torque output is greatly improved at slow speeds, making dual rear-wheel burnouts possible-even on a sticky dragstrip.

Orion 68RFE Six-Speed AutoYou can get the Cummins 6.7L with the familiar G56 manual transmission or the new six-speed automatic with a manual mode controlled by buttons on the shift handle. The 68RFE feels just as tough (or tougher) than its four-speed cousin, the 48RFE, but it's smoother around town. The shift programming is similar to the Allison transmission, but with less gear braking and the associated noise. The Orion does a good job of picking gears for the Ram (usually choosing the best ratio without hunting through the other five) and tries to keep the engine under 2,000 rpm at both 45 mph and 75 mph, which is great for fuel economy. Heavy throttle inputs result in firm and very fast shifts that don't require the engine to defuel noticeably like the Chevy and Ford trucks we've tested.

ResultsA trip to DC Performance and some time on the company's dyno showed the 6.7L makes 269 hp and 473 lb-ft of torque at the wheels, which is right on the money for the factory ratings of 350 hp and 650 lb-ft of torque at the engine. For reference, the Duramax LMM and 6.4L Power Stroke engines are rated around the same, but adding back 25 percent driveline loss to their dyno scores of 285 hp shows they could be making approximately 380 hp at the flywheel. So it's no surprise the dualie test Ram took about a full second longer to race the quarter-mile than the Chevy or Ford, but 16.7 seconds is still incredible for a truck that weighs 7,750 pounds-and that's more than a second faster than the pesky Prius.

Fuel economy during testing was good, with our best tank getting more than 16 mpg. This seems about right for a brand-new engine, and we hope Dodge is right about this being the most fuel-efficient Cummins ever sold in the Ram. It's definitely the quietest Cummins, according to our tests with a consumer-grade decibel meter. The scores were nearly as quiet as the Duramax LMM and 6.4L Power Stroke, which are barely louder than a gasoline V-8.

Is It Worth $54,465?The Ram provided for testing came with a steep sticker price, but that included $8,670 for the diesel engine and automatic transmission options-about the same costs found in the Chevy and Ford pricing. If you're a member of team Mopar, you'll be happy to know your money is being spent on the best Dodge diesel ever built. The engine is strong, quiet, clean, and appears to get decent mileage. The truck frame and body are the latest version of the Ram heavy-duty line, which is getting better with every update. If you don't like Dodge trucks, driving the 6.7L package may change your mind-just look at the reactions we got from the owner of an '06 5.9L and a new diesel power convert.