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Currently we see a lot of press about U.S. gasoline prices. As I write this, $4 per gallon for regular is just about the norm in my neighborhood, and TV pundits are noting that the national average is $3.91. Since January 2009, gasoline prices have risen from $1.84/gallon to their current peak, and the slow, steady climb continues. Thats a tough thing to take with the economy generally not so good.

There is legislation before both houses of Congress (HR 1687 and S1603, both in committee) to introduce incentives for alternative fuels, which will supposedly lower the cost of gasoline. Of course, there are more than just technical drivers for this legislation; lobbyists for every flavor of alternate fuel are doing their best to promote their favorite.

So what makes gasoline prices go up? The two components with the most impact are inflation and crude pricing. In addition there are transportation costs (from crude source to refinery and from refinery to dealer) and refining costs. There is also the corporate overhead for sales, administration, taxes, etc. And dont forget to add gasoline taxes, currently averaging 48.8 cents/gallon, says API. The cost of our finished gallon of gasoline also must include additives, the largest being ethanol (currently 10 percent of the total volume). Last but not least, there is the margin for the refiner and an additional margin added by the dealer.

The country would love to see lower prices for gasoline, but there isnt a lot in the above that can be dramatically changed. Of course producing more crude within the United States is one long-term answer – more raw material supply means lower prices – but whether or not there is the political will to do so is not the subject of this column.

That leaves us with the proposed answer, which is alternative fuels. Among the contenders are diesel fuel, methanol, ethanol and natural gas, as well as electricity for hybrids and all-electric vehicles. Each of these has its own unique issues and impacts on engine oil composition. Ill skip all-electric, since there wont be any engine oil in these vehicles, but what might the others need from engine oil?

When you research the thermodynamics, you find some pretty wide variations in energy content for each of these alternatives. Data from the government and other sources can give us a rundown of what many fuels offer in the way of energy (see table, page 9).

Diesel and Biodiesel

Looking first at diesel fuel, Im sure youre aware that its even more expensive than gasoline at the pump, by about 20 cents/gallon. However, diesel engines have the advantage of being more thermally efficient so their mpg is better. Its difficult to directly compare a vehicles diesel and gasoline performance since currently there are no engines that can run interchangeably on both fuels. However, the gasoline-fueled Chevy Cruze claims to get around 40 mpg, while a diesel version slated for introduction next year is targeted at about 50 mpg – 25 percent more.

Engine oil for diesels needs no magic. Since the early 1940s, these products have been formulated with additives designed to improve performance. With the next diesel oil upgrade in 2016, PC-11, there will even be a fuel-saving low-viscosity version which likely will find use in light-duty diesels. Automotive OEMs should be pretty comfortable with this choice since theyll be on solid ground technically.

Of course, there is the issue of biodiesel, and the team developing PC-11 will have to address its effects on engines and engine oils. So far, the biggest concern is fuel dilution in the oil, which leads to poor low-temperature pumpability. Additives probably can be introduced into engine oil formulations to handle the pumpability problem. There is also some concern about piston deposits with biodiesel, although newer engine designs dont seem to be as susceptible to this problem.

Theres a lot of talk about ethanol, so lets talk about it next. Brazil for decades has used ethanol as its primary fuel source since it has lots of sugar cane and not much petroleum to fuel its vehicles. A lot of lessons were learned during Brazils ethanol phase-in, including the impact of water on the fuel system, corrosion and seal compatibility plus the obvious reduction in energy output.

The United States came later to ethanol. Here, beginning in the 1970s, oxygenated fuel components like MTBE were added to gasoline to replace lead as an antiknock agent. However, in the 1990s MTBE began to appear in groundwater and was subsequently replaced by ethanol. Ethanol also brought a benefit for emissions reductions in certain areas. By 2003 MTBE had been essentially replaced by ethanol at 10 percent of the blend. Later, some engines were designed for so-called flex-fuel operation at up to 85 percent ethanol. Most recently, the EPA has approved the use of up to 15 percent ethanol for vehicles newer than 2001.

What Price Ethanol?

Ethanol produced in the United States comes largely from the fermentation of corn, however, so there is a plus/minus situation regarding fuel vs. food. The price of corn has gone up substantially and with it the price of feed for livestock, which results in increased food costs. Even your basic corn tortillas have gone up in price!

Ethanol has other baggage as well. First, it does not have as much energy per pound as gasoline. In fact, it has about 33 percent less, which translates into reduced fuel economy. At 10 percent of the gasoline blend, that doesnt amount to much more than 2 percent fuel economy loss and the benefits of lower emissions make it a reasonable trade-off.

However, at 15 percent ethanol becomes more of a problem, and even more so for other gasoline-fueled engines such as lawn mowers, leaf blowers and outboard engines. There is still no huge energy penalty to speak of, but there are concerns about system compatibility (fuel lines, seals and gaskets to name a few) as well as ethanols disturbing habit of picking up water. It remains to be seen how the small- and two-cycle engine manufacturers will deal with higher-ethanol blends.

What does an automotive engine oil designed for higher percentages of ethanol look like? Not too different from current oils designed for flex-fuel vehicles using the 85 percent ethanol known as E85. Because spark-ignited engines need some volatility in order to burn at low starting temperatures, and ethanol doesnt have sufficient vapor pressure at -40 degrees F to ignite, 15 percent gasoline is needed in the flex-fuel blend. Of course E85 has an energy penalty of about 20 percent and there are concerns about seal compatibility and water absorption as well.

Methanol, Good and Bad

Next, what about methanol? After all, the Indy Car circuit ran on methanol for years until ethanol became politically correct. The good news is that methanol is easy to make from renewable sources. The less-than-good news is that it has only about half the energy content of gasoline, so there are severe fuel economy penalties to be paid. Methanol also is very fond of water and creates some strange emulsions in the crankcase. There is a serious safety hazard as well, since methanol burns with an almost invisible flame. Indy race pit crews were trained to fall to the ground and roll if they felt heat anywhere on their safety suits. Each crew had a member whose sole duty was to hose down the area and any rollers, putting out the flames.

Methanol makes up for some of its low heating value with its high heat of vaporization. I suspect that methanol in passenger car service would burn similar to gasoline but youd need much better deposit control in the rest of the engine. I also expect that any fuel reaching the crankcase would hold on to water – and cause rust like we havent seen since the phase-out of leaded fuels.

Formulating an oil for methanol-fueled engines would likely require a spike in zincs to mix some additional antioxidancy along with good wear protection, as well as additional dispersency for contaminant control. Because methanol-fueled engines run very lean and result in very high temperatures in the combustion chamber, exhaust valve and turbo charger, additional ashless antioxidants and detergency will also be needed, to control piston undercrown deposits which can lead to detonation.

Gaseous Fuels

Were all familiar with LPG, or liquefied petroleum gases like propane. It would be hard to barbeque without it unless youre a throwback like me and still use charcoal. LPG and LNG (liquefied natural gas) have some distinct advantages: BTU equivalents greater than gasoline, known technologies for engines, and adaptability of current infrastructure. There is also a wealth of engine oil technology out there which now serves stationary and mobile natural gas fueled engines.

Engine oil challenges with these fuels are really more about oxidation resistance than deposits. Natural gas engines burn cleanly but are also hotter than conventional engines. Some of that can be managed by the vehicles cooling system, but the higher combustion temperatures will also require better oxidation resistance in the engine oil. Wear and corrosion can be problems if the fuel is wet or has higher than normal levels of sulfur.

The safety of gaseous fuels worries some, but is not an insurmountable problem. Since these gases are lighter than air, if a fuel system leaks the gas rises in the atmosphere rather than lying on the ground and burning. There might be a brief fireball but no persistent flames that splash and spread, as with liquid fuels.

The bottom line is that we can expect all sorts of fuels and fuel delivery systems will make their way into the marketplace. However, at the rate vehicles are being scrapped and replaced with new ones, it will be a long, long time before we see any significant changes in the way we power the majority of vehicles or the way we lubricate them.

As for me, if I go for any alternative, it will probably be diesel since I like the proven economy, durability and technical know-how. Dr. Diesel really knew what he was doing.

Gotta go now and light the barbeque!

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