I really like my job because it gives me an opportunity to talk not just to my friends under the guise of work, but also because I learn all kinds of cool stuff. So I’m on the phone recently with my buddy Andy Wicks who runs DynoTuneUSA. I met him when he was running the dyno for the DynoMax Exhaust Power to the Wheels dyno horsepower challenge back in 2007. Later, Andy also ran the chassis dyno at what is now the Street Machine Nationals in St Paul, Minnesota. Andy has run thousands of cars across his dyno.
Andy’s shop is in Watertown, South Dakota. It’s a small Midwestern town but he tunes some of the baddest, big-horsepower cars in the country. As you might expect from the Midwest, farming and growing corn is big business. The logical offshoot of raising corn in this area is there is an ethanol plant, Glacial Lakes Energy, nearby. Because Andy has a great relationship with the plant and is a big proponent of ethanol fuel, Andy has been involved in some interesting tests.
You may have read something about the EPA looking into the possibility of pushing ethanol percentage from the current 10 percent to 15 percent. In shorthand, 15 percent ethanol is called E15. If you have read anything about this proposal, there was considerable pushback to this recommendation although later both the EPA and Department of Energy stated that cars built from 2001 and newer could easily accommodate E15 without an issue. This is only a 5 percent change in the concentration of alcohol in the fuel but there was quite a bit of controversy about this proposed change. The main reason for this change was an attempt to reduce the sulfur emissions from gasoline.
One of the more interesting “sound bites” was an alarmist quote that stated “This is a 50 percent increase in ethanol.” While that statement is technically true in a very narrow sense, the proposed increase to E15 was really only a total change in concentration from 10 to 15 percent – which when I went to school meant only a 5 percent change. So whenever you see percentages used in a story, think about what’s really going on rather than just blindly following the rhetoric. Often times, numbers can easily be used to misdirect.
Lately, Andy has been doing some experiments with E30, which is 30 percent ethanol and 70 percent gasoline. Pure ethanol has an anti-knock index (AKI) of roughly 115. So mixing 30 percent ethanol even with a tame 87 octane base gasoline raises the overall octane of E30 to roughly 94.5. Normal pump gas premium throughout most of the country is either 91 or 93 octane. So a pump fuel with almost 95 octane would seem to be a substantial benefit.
Andy began his experiments by blending his own fuels. One example that he showed me was a 2012 V6 Camaro where after basic driving and recording the number of knock retard episodes on a data logger using normal E10 87 octane gasoline. This was followed up with similar driving loops with E30. The results were amazing. Running on E10, in the range of 50 to 60 percent throttle opening, the engine pulled timing back with knock sensor episodes a total of 59 percent of the time. When the E30 was used, timing retard was cut by more than half to 26 percent.
Today with sophisticated electronic engine controls, engineers can push the static compression ratio up and rely on the knock sensor to retard the timing and keep the engine out of detonation. And that’s exactly how these engines are now tuned – in an attempt to pull as much fuel mileage out of these engines as possible.
When you can run these engines on a higher octane fuel, the knock episodes drop off dramatically. When that happens, the engine enjoys a more aggressive ignition curve and power improves. The net result is that with a more efficient engine benefiting from a higher octane fuel, fuel mileage actually improves in some cases because the engine is running more efficiently with a more aggressive ignition curve.
This appears to fly in the face of the usual attack on ethanol. The naysayers contend (correctly) that ethanol has roughly 30 percent less energy per pound compared to gasoline. So that means the engine must use 30 percent more fuel just to go the same distance. This is a valid point – as long as we’re talking about an engine designed to run on low quality gasoline.
But Andy’s testing has shown is that small, turbocharged engines that have to work harder to push that vehicle down the road really respond to the added octane to the extent that their mileage in daily driving actually improves! Again, that’s because the ignition timing is not being pulled back by the knock sensors. In effect, smaller engines like the Ford EcoBoost gasoline direct-injection four cylinder, for example, are what you would want to design as an ethanol-friendly engine that can take advantage of the improved octane.
So the point of all this is that there seems to be something to this whole E30 fuel idea. Of course the big oil companies won’t like it. But Andy has seen tests where lots of late model engines are completely happy at this percentage with no problems that were directly related to the higher concentration of ethanol. To be fair, it’s also possible that many engines would be running with significantly greater injector duty cycles that could light up Check Engine lights because the engine is operating outside of the original tuning parameters. However, an ethanol company called Glacier Lakes has created mixing pumps in the town of Watertown, South Dakota and hundreds of cars have used the E30 fuel and, according to Andy, they have not seen any reports of Check Engine lights directly related to the increased ethanol fuel percentage.
I’m already thinking about a test on a carbureted engine like my supercharged blow-through 4.8L engine. Mixing 7 gallons of 91 octane pump gas with 3 gallons of ethanol (E98) would create my own rough equivalent of E30. Actually that would be a little bit higher ethanol percentage because the 91 octane is already E10. With 94 octane fuel – my centrifugal supercharger might really like the added octane along with the added cooling effects of the alcohol. I will certainly have to re-calibrate the carburetor to compensate but that doesn’t appear to be difficult.
I thought about buying isopropyl alcohol at the local pharmacy but that’s too expensive. There’s a gas station about 20 miles from me that sells E85. It would be a lot easier just to mix the E85 with straight gasoline to make my E30. I found a mixing ratio calculator online and 6 gallons of E85 mixed with 14 gallons of pump 91 that is E10 will produce E32.5 which is close enough!