Re: 10 % ethanol
Absolutely wrong. I don't understand why people perpetuate false information. E-10 at 93 octane is no more detonation resistant than straight gas with MTBE rated at 93 octane. 93 is 93, doesn't matter how you get there.
In my area when they still used MTBE we used to have 94 octane, I got rid of my high compression 302 in my car and replaced it with a lower compression 460. The timing curve I had to run with 93 was not ideal and I noticed a loss of power and about a 3 MPG loss on highway when switching from MTBE 94 octane to E-10 93 octane with less timing. I get better highway MPG with the 460 running E-10 89 octane (16 MPG) than I do with the 302 running E-10 93 octane (14), though the 302 on MTBE 94 octane was around 17 MPG highway.
Regardless, E-10 has about 3% less energy (BTU) per unit of volume than straight gas. So apples to apples, same motor, octane, but jetting changed to keep mixture proper with E-10 (on a Holley carb on most mild engines 1-2 jet size increase will do, PVCR and idle feed restrictors generally won't need enlarging for such a small change).
Personally, on a slightly different note, I'm looking forward to broader E-85 adoption from a performance standpoint. I believe E-85 is either 110 or 115 octane. This would allow for some truly impressive performance, probably dynamic compression ratios around 10:1 and static 11-12:1. This would lessen the cost IN MPG but significantly increase HP per cubic inch capability on pump gas.
Absolutely wrong. I don't understand why people perpetuate false information. E-10 at 93 octane is no more detonation resistant than straight gas with MTBE rated at 93 octane. 93 is 93, doesn't matter how you get there.
In my area when they still used MTBE we used to have 94 octane, I got rid of my high compression 302 in my car and replaced it with a lower compression 460. The timing curve I had to run with 93 was not ideal and I noticed a loss of power and about a 3 MPG loss on highway when switching from MTBE 94 octane to E-10 93 octane with less timing. I get better highway MPG with the 460 running E-10 89 octane (16 MPG) than I do with the 302 running E-10 93 octane (14), though the 302 on MTBE 94 octane was around 17 MPG highway.
Regardless, E-10 has about 3% less energy (BTU) per unit of volume than straight gas. So apples to apples, same motor, octane, but jetting changed to keep mixture proper with E-10 (on a Holley carb on most mild engines 1-2 jet size increase will do, PVCR and idle feed restrictors generally won't need enlarging for such a small change).
Personally, on a slightly different note, I'm looking forward to broader E-85 adoption from a performance standpoint. I believe E-85 is either 110 or 115 octane. This would allow for some truly impressive performance, probably dynamic compression ratios around 10:1 and static 11-12:1. This would lessen the cost IN MPG but significantly increase HP per cubic inch capability on pump gas.
I was able run slightly more aggressive timing at certain rpm's and more boost with zero 'counts' of knock on E-10 than straight 93. And way more timing with E-85, that stuff is like race gas in a modded turbocharged engine. BTW, some turbo motors with larger aftermarket turbos have a slight amount of detonation at spoolup but with E-10 it goes away. And with E-85 I was able to add in several more degrees of timing at 4500rpms with zero knock.
