The WardsAuto editorial team is hip-deep in 10 Best Engines testing, about halfway through the 45 engines we are evaluating by the end of this month.
Each engine features lots of advanced technology, and it’s essential that we write spec sheets about every entry to share with the staff covering the salient points about fuel economy, output, strategic positioning, etc.
In addition to including bore, stroke, compression ratio and valvetrain control, these sheets often will include relevant information from the automaker and nuggets gathered along the way from interviews with company engineers.
Below is part of the sheet for Chrysler’s 3.0L turbodiesel V-6 in the ’14 Ram 1500 and Jeep Grand Cherokee:
We’re driving six diesels this year for 10 Best Engines, but this is the only one found in a truck, the Ram 1500. It’s worth noting after more than a decade of Detroit auto makers talking about and even spending money to develop light-duty diesels for fullsize half-ton pickups, Chrysler is the first to pull the trigger on a powertrain strategy that has seemed like an absolute no-brainer.
How do you think the Ram stacks up to all the other diesels we’re driving – from Mercedes, Audi, Chevy and BMW?
Yes, this Laramie Longhorn comes with a base price of $48,915, but this engine can be had in Tradesman trim for just over $30k. The price premium for diesel fuel is another moving target. I saw a $0.10 premium last week, while someone else saw it $0.80 higher in another part of metro Detroit.
The Ram diesel comes from VM Motori, which is owned 100% by Fiat.
Bob Lee, Chrysler vice president and head of engine and electrified propulsion engineering, says “it virtually cost us nothing” to slot the engine into the Ram, because all the engineering had been done and paid for in Italy.
Another smart feature: Chrysler’s new 8-speed automatic transmission, which boosts fuel economy and makes for smoother shifting. It’s standard with the diesel.
Fuel economy during our testing has been between 22 and 24 mpg (10.6-9.8 L/100 km) – not bad at all for a vehicle that can tow 7,450 lbs. (3,379 kg). EPA numbers will be coming soon, hopefully.
Speaking of hauling, Lee also says the 3.0L diesel is better at towing in certain conditions (i.e. on flat roads in the Midwest) than the 5.7L Hemi gasoline V-8. The diesel is available in all 50 states.
On the technology front, Chrysler gets by with conventional solenoid injectors, rather than more expensive, faster-acting piezo electronic injectors, while still managing to enable up to eight injections per combustion event.
It’s the multiple injections at extremely high pressure (2,000 bar [29,000 psi] in the case of Ram), rather than the single shot of fuel from the old days, that mitigates a lot of the clatter associated with diesels.
Another really cool feature is the auto glow plugs. On a cold day, when you start the engine, the system delays engaging the starter for several seconds while the glow plugs begin heating up the block.
In the old days, especially with heavy-duty diesels, you did that on your own, turning the key just far enough to activate the accessories and pre-heat the glow plugs. After several seconds, you'd start the engine and the clatter would be less pronounced.
Chrysler says this feature is not a world-first, but this is the first application of these particular ceramic glow plugs that heat up rapidly and have a capacity for higher temperatures.
The single variable geometry turbocharger is electronically actuated, and the housing is water-cooled.
The selective catalytic reduction urea tank needs to be refilled every 10,000 miles (16,093 kg). The engine also incorporates cooled exhaust-gas recirculation to reduce oxides of nitrogen emissions, as well as a diesel oxidation catalyst and diesel particulate filter.
Chrysler expects the Ram diesel take-rate to be about 15%.
On the downside, gasoline engines have gotten so much cleaner and fuel-efficient that Lee says the 25% advantage diesel has held for many years has fallen now to about 15%.
Food for thought.