A Tale of Two Automakers,
Continued

“U.S. automakers are committed to flexible fuel-capable vehicles (that can run on both gasoline or ethanol),” he said. “As second-generation biofuels become available, especially cellulosic-based ethanol from plants like switch grass rather than corn, we will see more domestically produced renewable fuel manufactured. If the infrastructure is in place to handle this type of fuel, and it will be if the demand is there, we will see greater volumes of flexible fuel vehicles.”

With the introduction of so many new technologies, the question of how these systems will impact the lube industry looms large. Fortunately, Trajnowski said he foresees no major shift from vehicles that are powered, at least in part, by internal combustion engines, the lubrication needs of which should remain largely unchanged in coming years.

“We don’t expect any durability compromises vis-à-vis smaller displacement engines utilizing turbocharging,” he said.

While it is possible Ford may extend oil change intervals from its current 7,500 miles after the expected introduction of GF-5 motor oil next fall, the increasing use of biofuels, which run hotter than gasoline engines, may put more pressure on motor oil, a factor that could contribute to intervals remaining static for the time being. And, according to Trajnowski, it is the biofuel trend that, for Ford at least, could impact the market the most.

“Automakers will not abandon the internal combustion engine anytime soon, but I do expect that biofuels will begin to replace petroleum sometime in the next decade,” he said.

GM’s Strategy: Enabling Existing Hardware

Like Ford, GM expects to meet new fuel economy standards in a number of ways. With the introduction of its new Chevrolet Volt sedan next fall, the company will be the first to introduce a “series” hybrid vehicle, wherein a gas engine is used to generate electricity to power four electric drive motors. It’s essentially an electric vehicle with its own portable generator, unlike traditional parallel hybrids that use an electric motor in combination with a gas engine to power a conventional or continuously variable transmission. At an expected cost of $40,000, though, it remains to be seen whether the high-tech Volt will become popular enough to warrant widespread adoption of its powertrain in other vehicle models, especially in light of gas prices that are historically affordable.

To hedge its bets, GM is also investing in technology that will make vehicles lighter and that will improve combustion efficiency. Some of the high-tech systems that will accomplish the latter include:

• Direct injection.
• Cam phasing.
• Variable valve lift.
• Turbocharging.
• Displacement on demand.

It is to meet the needs of some of these systems that GM is adopting its own proprietary motor oil later this year, a product to be known as dexos.

“These technologies will allow us to get more power out of a smaller package,” said Eric Johnson, senior project engineer with GM’s Powertrain, Fuels and Lubricants Group. “And by acting as a functioning hydraulic fluid, (dexos) will help us enable new hardware technology.”

According to Johnson, the goals for dexos are improved fuel economy, improved fuel economy retention (which will allow the motor oil to maintain its fuel economy benefits throughout the life of the oil), improved aeration performance and more efficient drain intervals. The key factor for dexos — and one of the reasons that motor oil manufacturers suggest it will almost certainly require synthetic base oil and expensive additives like molybdenum — is its improved aeration performance.

One of GM’s key fuel economy initiatives is displacement on demand (GM calls its “Active Fuel Management”), a system whereby one or more engine cylinders can deactivate depending on power requirements. Take, for example, the 5.3L V8 engine that powers most GM trucks and large SUVs. Under hard acceleration or when towing or carrying a load, all eight engine cylinders are engaged and provide full power to the vehicle. However, at highway cruising speed or when less power is needed, the vehicle’s onboard computer deactivates cylinders by shutting off fuel to those cylinders, thereby effectively making the V8 a V6 or even a V4 engine. This helps the engine achieve near class-leading fuel economy in many applications.

However, alternately starting and stopping cylinders puts a lot of stress on motor oil, one of the reasons GM’s dexos specification calls for improved aeration performance versus traditional motor oil.

Any way you slice it, dexos is a key driver toward GM’s aim of improving fuel efficiency. Synthetic motor oil has long been touted by some companies for its fuel efficiency benefits, and it appears GM aims to put those claims to the test with dexos.

“Every little tenth of fuel economy is important to OEMs right now,” Johnson said. Johnson said GM decided to implement its own specifications for a number of reasons.

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