Ethanol is Awesome! Really?
Lucky at ARD this week writes about E85, what I believed to be pure evil when taken in the context of efficiency and performance. Not so. “Burn temperatures are lower, initial octane rating is much higher than gasoline at ~105, and it’s not uncommon at all to gain 40bhp+ by using E85 alone with no other changes aside from tuning. It does require larger injectors in most cases and some considerable re-tuning of the ECU to take advantage of the octane. For those who might remember the days of adjusting ignition timing at the distributor and feeling the gain of power by just a few degrees of ignition advance, E85 allows for as much as 7-8 degrees of additional ignition advance which can translate to some serious power gains!”
Pros & Cons of E85 in Your Volvo
E85 by nature has less energy density than gasoline, which means you have to use ~34% more of it to get the same amount of power as you would from a similar mass of gasoline. While E85 is typically 30-35% less costly than gasoline this alone is not enough to justify its use from a standpoint of cost savings alone. There’s also the consideration of additional engine wear that is attributed to E85 usage over time. Depending on engine construction and model year of vehicle the vehicle components may be more or less resistive to E85 and its effect on rubber/plastic engine parts as well as the cylinder head and pistons themselves. Most fuel injected vehicles from 1980 and on by law are required to tolerate up to 15% ethanol content in the regular fuel supply while most will handle upwards of 30% without issue.
However Ethanol is also hygroscopic which means it is prone to absorb water from the air and condensation so there can be a concern of water entry into the fuel delivery systemwhich can create problems down the road if you live in a high humidity environment. Rusted fuel pumps, injectors, and fuel lines can be a concern if the vehicle sits for long in a humid environment. Lastly is the concern around corrosivity or reaction to aluminum components in then engine. Methanol is corrosive when it comes to aluminum and related parts, ethanol is not. This confusion is typically where people get the idea that E85 will be corrosive and damaging to an engine. For most applications there will be only minor additional wear to the engine if the ECU is properly tuned for E85 usage.