Texasmark
Supreme Mariner
- Joined
- Dec 20, 2005
- Messages
- 14,780
Re: any fuel experts here
Oh, QC, excuse me. You are talking about almost 100% alkie and I thought you were talking the other way around.<br /><br />Now that you are talking BTU's we are on the same sheet. I'll read more and respond more....<br /><br />I guess I do confuse octane with heat content and agree it has nothing to do with it. Also makes since that the pumps will still dispense 87 octane regardless of the heat content of the fuel.<br /><br />Understanding that the heat content is the energy (fuel) that you are converting to work, via the engine's combustion chamber and drive train, and work is the consumption of energy (in this case gasoline measured in BTU's), so if alkie is low on BTU's then you will get less whoopie and have a reduction in mpg since to move a given mass a given distance in a given time requires x BTU's if you get less BTU's you will get less response. <br /><br />So to compensate, you step on the accelerator harder, putting more fuel into the engine which compensates for the lower BTU's with ethanol and you get back to the MPH you were running with your mass traveling the distance you were traveling, but it is taking more fuel to do it.<br /><br />Phew. I think I understand that. <br /><br />So, in the case of an OB, WOT is all you can get so if your BTU's are lower, your MPH will be lower. Can't deny that. Glad I saved my old lower pitch prop. I might need it with this new fuel.<br /><br />Sorry for my stupidity but this makes sense. <br /><br />Thanks,<br /><br />Mark
Oh, QC, excuse me. You are talking about almost 100% alkie and I thought you were talking the other way around.<br /><br />Now that you are talking BTU's we are on the same sheet. I'll read more and respond more....<br /><br />I guess I do confuse octane with heat content and agree it has nothing to do with it. Also makes since that the pumps will still dispense 87 octane regardless of the heat content of the fuel.<br /><br />Understanding that the heat content is the energy (fuel) that you are converting to work, via the engine's combustion chamber and drive train, and work is the consumption of energy (in this case gasoline measured in BTU's), so if alkie is low on BTU's then you will get less whoopie and have a reduction in mpg since to move a given mass a given distance in a given time requires x BTU's if you get less BTU's you will get less response. <br /><br />So to compensate, you step on the accelerator harder, putting more fuel into the engine which compensates for the lower BTU's with ethanol and you get back to the MPH you were running with your mass traveling the distance you were traveling, but it is taking more fuel to do it.<br /><br />Phew. I think I understand that. <br /><br />So, in the case of an OB, WOT is all you can get so if your BTU's are lower, your MPH will be lower. Can't deny that. Glad I saved my old lower pitch prop. I might need it with this new fuel.<br /><br />Sorry for my stupidity but this makes sense. <br /><br />Thanks,<br /><br />Mark