What Is E85 And Where Can One Get It?
The blue card that identified itself as an "Alternative Fueled Vehicle Buyer's Guide," included with the GMC owner's manual package, didn't provide any clues to what kind of alternative fuel the GMC burned. The GMC owner's manual doesn't make any mention of E85 being an alternative fuel but does devote one page to decoding the VIN number (VIN Code Z) to let operators know if E85 can be used. Briefly, the owner's manual mentions that E85 is a "renewable fuel" made from renewable sources such as corn and other crops, but nowhere is the term "alternative fuel" mentioned.
When it comes to learning about where E85 can be purchased, GMC refers its truck owners to visit the U.S. Department of Energy at their alternative fuels website. We checked it out, and unfortunately, the DOE fails to mention that of the three E85 stations serving California's population of 33,871,648 people, only one station is accessible to the general public and it's in San Diego (Chula Vista). The good news is they have a double-sided pump capable of servicing two vehicles at a time...whoopee!
What exactly is E85? As defined by the U.S. department of Energy, E85 is a motor fuel blend of 85 percent ethanol and 15 percent gasoline. According to the National Ethanol Vehicle Coalition (NEVC), "E85 has the highest oxygen content of any transportation fuel available today, making it burn cleaner than gasoline. Not to take the NEVC's word for it, we conducted an E85 search on the State of California's official website and sure enough, California confirmed the NEVC's claim. It went on to state ethanol contains 50 percent more oxygen than Methyl Tertiary Butyl Ether (MTBE). (Before MTBE was identified as a carcinogen in California, the state consumed more than 25 percent of the world's annual MTBE production.)
According to the State of California's website: "MTBE has caused public concern because it can contaminate groundwater (along with other gasoline components) when underground fuel tanks leak. MTBE moves faster in water than other fuel components and, in small amounts, renders drinking water unusable. On March 25, 1999, Governor Davis declared that MTBE presents an environmental risk to California and directed California State agencies to take steps towards eliminating its use in California gasoline by December 31, 2002. The Governor's actions were consistent with the findings and recommendations of an MTBE assessment performed by the University of California. In March 2002, the Governor directed that the prohibition of the use of MTBE be postponed for one year. The Governor found that it was possible to eliminate use of MTBE on January 1, 2003, without significantly risking disruption of the availability of gasoline in California."
Initially, the stated reasons, MTBE was chosen over ethanol because it could be blended at the refinery whereas ethanol has to be blended at the distribution center, and it was cheaper to buy.
The NEVC says the advantage of E85 over currently available conventional gasolines is "fewer exhaust emissions result in reduced production of smog and a decline in respiratory illness associated with poor air quality. E85 also reduces greenhouse gas emissions such as carbon dioxide, the main contributor to global warming, as much as 39 to 46 percent compared to gasoline."
That's all great news, but as performance enthusiasts what impressed us the most about E85 was its 105 octane rating and its inherent ability to deliver a much cooler intake charge than conventional gasoline.
What this means to gearheads is, we can run higher-compression ratios, pull more ignition-advance, and make a lot more horsepower-all this while spending less money than for regular unleaded gasoline
We've read test data (7-year-old research) claiming E85 delivers lower fuel mileage than 87-octane unleaded, but the mileage testing we conducted recently on our '05 L59 GMC didn't confirm these old findings. To the contrary, during our first run from Las Vegas, Nevada, to Anaheim, California, the GMC averaged 21 mpg on 87-octane unleaded gasoline. We repeated our Vegas-to-Anaheim trip with 105-octane E85 and averaged 22 mpg. Granted, we didn't employ SAE-controlled test methods, but in the real world we figured these were reliable enough statistics to understand E85 a little better.
The key to impressive fuel mileage from E85 seems to be whether or not a vehicle is capable of optimizing ethanol's power potential. We suspect the earlier FFVs tested were tuned for gasoline and not capable of automatically recalibrating the engine's fuel and timing for ethanol.
If someone from General Motors could verify whether an '05 L59 engine optimizes for E85, we would like to know. The only vehicle we have proof positive that optimizes for E85 is the new Saab 9-5 2.0 BioPower. Saab released figures that the 9-5 BioPower cranks out more horsepower and performance when it's running on E85 than on unleaded regular gasoline. The Saab's turbo motor produces 180 brake horsepower (bhp) with E85 and 150 bhp on gasoline. On top of a 20 percent increase in maximum horsepower, 16 percent more torque is produced with E85 over conventional gasoline. We should mention the Saab senses the presence of E85, which recalibrates and adjusts the engine management system to accommodate the different timing characteristics and the air/fuel mixture requirements of ethanol. Saab says that the new turbo flex-fuel engine improves fuel consumption under mid- to high-load driving because fuel enrichment for engine cooling is no longer necessary. The Saab is also turbo-charged, which provides the ability to alter the engine's effective compression ratio by increasing turbo boost to accommodate the higher octane rating of ethanol over pump gas. We don't expect to see 20 and 16 percent power gains in a naturally aspirated scenario by simply switching to E85.