GMC Sierra Hybrid
GMC Sierra Hybrid. Click image to enlarge

Review and photos by Howard Elmer

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The future of pickup truck engines

This year, the latest generation of Ford F-150 and Dodge Ram trucks were unveiled. Both made significant cosmetic and mechanical upgrades, but both are still on the high side for fuel consumption (though Ford did bring a new six-speed transmission to market and some engine changes). This fact, and skyrocketing gas prices in the early summer, pretty much tanked truck sales. Since then, this volatile gas market has dropped back below a dollar a litre, but the question has to be, for how long? Frankly, the wise move for all truck makers is to use this current gas price reprieve to move towards better fuel saving options.

One of the fuel saving measures you can expect to see in the next two years from the truck makers is new smaller diesel engines available in the Ford, Dodge and GM half-ton trucks by the 2010 model year (that translates to at least seeing a pre-production unit as early as the Detroit Auto Show this coming January). Toyota is the exception as they have not announced a similar move, but they will probably follow as soon as they can build a suitable engine.

GM two-mode hybrid transmission
GM two-mode hybrid transmission. Click image to enlarge

What else? Hybrids, of course. The best-kept secret here is that these already exist. GM has a two-mode hybrid system that they put in the Tahoe this year and that Chrysler put in its Aspen SUV just this summer. This hybrid system I’m referring to is built by the Hybrid Development Center in Troy, Michigan, and is owned jointly by GM, Chrysler, Mercedes and BMW. As far as half-ton pickups go, it is planned for Chevy and GMC trucks this January (these are built in Oshawa, Ontario by the way) and Dodge has already announced that it will follow suit with the same system available in the new Ram pickup sometime next year.

This two-mode hybrid (which people mistakenly refer to as electric/gasoline) is designed to power the truck from zero up to 30 km/h on electric power (that’s one mode) – then this electric motor is used to assist the MDS (cylinder deactivation) function by adding in power at highway speeds so the engine can remain in four-cylinder mode for as long as possible (that’s the second mode).

This low and high-speed assist is offered by the electric motors housed in the transmission case, and is known as ECVT (electric continuously variable transmission). Also, at stoplights, the engine shuts off (all the electrical functions remain on though); this too saves fuel, particularly for trucks used mostly in the city. But if you do hit the gas hard the engine responds normally.

The battery array is built by Panasonic and housed under the second row seats. An eight-year warranty on the batteries means that most owners will never even see the batteries, let alone have to worry about them.

GMC Sierra Hybrid
GMC Sierra Hybrid. Click image to enlarge

To give you some idea of what this means in terms of power output, I’ll refer to the figures as provided recently by Chrysler for the 5.7-litre V8 Hemi hybrid with MDS that powers its new Aspen SUV (and will also do duty in the Ram). The engine makes 345 hp and 380 lb-ft of torque on its own. Add two AC synchronous electric motors that draw 300 volts maximum, and you get an additional 87 hp and 235 lb-ft of torque. As for fuel consumption, Chrysler is claiming a 40 per cent savings over a non-hybrid Aspen.

Also note the torque figure – this is significant particularly where towing is concerned. And this system is built to tow: while final numbers are not yet available, it can be surmised that the towing capability will be similar to that of the SUVs – and that is up to 6,000 lb.

Diesel engines are favorites among HD truck buyers. In fact, Ford says that over 80 per cent of its Super Duty buyers (F250 and up) order the turbo diesel option, at a cost of $8,570. Assuming that half-ton owners would also like a diesel option is not really a reach, however the price difference between gas and diesel options may take some of the shine off the introduction of these new half-ton diesel engines.

At present we don’t know what these diesels will cost, but you can bet it will be more than the gas engine and that may be where the gains in fuel economy and longevity may be lost.

Ford EcoBoost
Ford EcoBoost. Click image to enlarge

While diesels have always been more expensive to build, the other reason for this price difference is the new emission systems (government mandated) which eliminate up to 97 per cent of the particulate output – a figure on par with gasoline engines – and that cut nitrogen oxide (NOx) output to almost zero.

This process, while necessary and “green,” is what adds cost to these new diesels. Look at what has to be done just to clean up the soot: particulate matter no longer goes out the tailpipe; instead it’s captured in a ceramic honeycomb filter. Then to clear the particulates and prevent clogging, a regeneration process burns the trapped particulates and cleans the filter using high exhaust gas temperatures. This technology is not cheap.

For this reason, Ford has gone in another direction. EcoBoost is a fuel injected, gas-turbo combination that Ford says is fuel efficient and affordable.

“Compared with the current cost of diesel and hybrid technologies, customers in North America can expect to recoup their initial investment in a four-cylinder EcoBoost engine through fuel savings in approximately 30 months,” said Derrick Kuzak, Ford’s group vice president of Global Product Development. “A diesel in North America will take an average of seven and one-half years, while the cost of a hybrid will take nearly 12 years to recoup – given equivalent miles driven per year and fuel costs.”

Of course, this statement is dependent on where the price of fuel is – but in percentage terms, EcoBoost is said to offer up to 20 per cent better fuel economy, and make 15 per cent less CO2 than an equivalent non-EcoBoost gas engine. It is also coming in a V6 version which will probably make it into the F-series pickup.

Still, Dodge says that with its Cummins clean-diesel technology, the all-new turbo diesel engine they intend to deliver in the light-duty Ram pickup will affect a dramatic increase in low-end torque, offer up to a 30 per cent improvement in fuel economy and a 20 per cent reduction in CO2 emissions – compared to an equivalent gasoline engine.

While these claims, currently, are still just pie-in-the-sky, we can look at the 3.0-litre V6 diesel engine (built by Mercedes-Benz) that is currently being offered in the Jeep Grand Cherokee for comparison. It makes 215 hp and 376 lb-ft of torque and consumes just 9.0 L/100 km. When I drove it last year, it cost $1,500 dollars more than the gas HEMI version. That’s not bad, but with even more stringent environmental regulations this year, that figure may rise.

GM currently offers 17 diesel engine variants in 45 vehicle lines around the world. That equals more than one million diesel engines sales annually, and what’s significant about this for North America is the knowledge that companies like GM and Ford have. This tremendous depth of diesel knowledge acquired through their branch operations around the world is what should help them react to this new fuel challenge quickly – though you’ll have to wait at least a year.

The engine GM intends to put into its half-tons is a new 4.5-litre V8 Duramax turbo-diesel. In comparison to a similar sized gasoline engine, GM says the 4.5L will improve fuel efficiency by 25 per cent and reduce CO2 emissions by 13 per cent.

GM 4.5-litre V8 Duramax turbo-diesel
GM 4.5-litre V8 Duramax turbo-diesel. Click image to enlarge

This new V8 diesel engine will fit the same space as a small-block V8 gas engine. This opens up the possibility of swapping engines across the line should future market demand it. Output of this engine will be rated in excess of 310 hp and 520 lb-ft of torque. I drove an early “mule” version of this engine at GM’s test facility last summer and I can tell you that this is a significant amount of power for a half-ton, in a quiet-running, high-torque package. And it may be what the market demands (that remains to be seen) but it’s also good to know that there are other engines that GM could make available; like the new 250-hp, 2.9-litre diesel V6 they just introduced for the European market. It’s said to offer 40 per cent more power, along with reduced fuel consumption compared to the engine it is replacing.

Ford, of all the truck builders, has been the most secretive about what size and kind of diesel they will offer in 2010, but it is possible that they will be building it themselves, at the new engine plant in Mexico.

Toyota is the other big question-mark right now. But, having invested over two billion dollars in a new truck plant in San Antonio, TX (building just the new Tundra) it’s obvious they are committed to being a player in the half-ton market. And certainly the current Tundra is the equal of any half-ton on the market. Their problem is that they have the fewest engine options of all the builders. How or when they will move forward with new powertrain offerings is a closely guarded secret; I’m sure they will – as they also have a depth of world diesel experience.

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