10% Ethanol in Gas
in [Technical]
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From: Mike on 24 Dec 2007 19:37 "Steve Austin" <saustin4(a)twcny.rr.com> wrote in message news:476fe812$0$4990$4c368faf(a)roadrunner.com... > Mike Romain wrote: >> jim wrote: >> >>> Here's the problem: >>> What your engine does or does not do above 3000 RPM has nothing to do >>> with getting good gas mileage. >> >> If the top end is 3500 RPM, which is 'full throttle or the pedal to the >> metal, then cruising at 2300 rpm needs about 3/4 of the throttle pedal. >> >> When the top end is 4500 rpm on the same engine, again that is pedal to the >> metal, then cruising at 2300 rpm only needs about half throttle. >> >> This 25% difference in the gas pedal position 'sure' appears to translate >> into a sweet 25% 'increase' in gas mileage. >> >> It has for me and over a half dozen others I have tuned up with the >> emissions 'governor' gone. >> >> Why is this hard to understand? >> >> Mike >> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 >> 'New' frame in the works for '08. Some Canadian Bush Trip and Build >> Photos: http://mikeromainjeeptrips.shutterfly.com > > Better gas mileage comes from having the throttle opened more, not less. > This is the main purpose for egr now. More throttle with more dead gas > equals less pumping losses. Not quite. A larger throttle opening improves the volumetric efficiency of an engine. This does not mean that driving at full throttle will give you better mileage. The main purpose of EGR is to reduce Oxides of Nitrogen.
From: jim on 24 Dec 2007 20:26 > If you add more fuel you get a bigger bang in the > cylinder which delivers more power to the rear wheels, which carries the > vehicle further down the road. No incorrect. What that illustrates is your complete lack of understanding. A car does not skid along the road like a hockey puck propelled by little puffs of fuel explosions like you imagine. Driving down the highway (in high gear) the crankshaft is linked to the wheels directly in such a way that each explosion caries the vehicle exactly the same distance no matter whether you imagine the explosions are big or little. That is if you drive from point A to point B in top gear there will be a fixed number of engine revs involved. What more power to the piston means is that you get their faster. That is, the piston moves faster so the car goes the same distance in less time. So if you think about what you are saying (obviously, not something you are used to) your claim is that the faster you go (i.e. the more throttle) the better the gas mileage. That is just plain wrong.
From: * on 25 Dec 2007 06:02 news <rollingviolation(a)domain.invalid.com> wrote in article <O0maj.21349$Tx.5194(a)pd7urf3no>... > phaeton wrote: > > I'm not anti or pro ethanol. > > Here's what I know/read/been told as to why some people like/don't like it: > > You know how some cars just don't like certain brands of spark plugs? > Some cars just don't seem to like ethanol. > > Ethanol has a higher octane rating, so, in theory, you could make more > power from it. Only if you increase the engine's compression to take advantage of the octane - or resistance to detonation......that's what is done in race cars that run alcohol-based fuels. > Ethanol has less energy per unit volume than gasoline, so, in theory, > you get worse fuel economy, but not always: > That's a true statement that stands on its own. Ethanol and methanol both produce fewer BTUs than gasoline when burned, thus put out less horsepower-per-gallon - requiring larger quantities to put out the same power as gasoline. Most race cars using alcohol-based fuels run approximately twice the volume of alcohol as they would gasoline.
From: Don Stauffer in Minnesota on 25 Dec 2007 11:01 On Dec 24, 10:10 am, Mike Romain <roma...(a)sympatico.ca> wrote: > jim wrote: > > Here's the problem: > > > What your engine does or does not do above 3000 RPM has nothing to do > > with getting good gas mileage. > > If the top end is 3500 RPM, which is 'full throttle or the pedal to the > metal, then cruising at 2300 rpm needs about 3/4 of the throttle pedal. > > When the top end is 4500 rpm on the same engine, again that is pedal to > the metal, then cruising at 2300 rpm only needs about half throttle. > > This 25% difference in the gas pedal position 'sure' appears to > translate into a sweet 25% 'increase' in gas mileage. > > It has for me and over a half dozen others I have tuned up with the > emissions 'governor' gone. > > Why is this hard to understand? > > Mike > 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 > 'New' frame in the works for '08. Some Canadian Bush Trip and Build > Photos:http://mikeromainjeeptrips.shutterfly.com Because throttle opening and rpm are only connected in steady state, i.e, cruising on level ground at constant speed. But cars get pretty good milage under those conditions anyway. It is acceleration where we lose a lot of efficiency, and during acceleration rpm and throttle opening are not uniquely connected.
From: * on 27 Dec 2007 03:26
Scott Dorsey <kludge(a)panix.com> wrote in article <fkgo1g$3js$1(a)panix2.panix.com>... > > 10% ethanol won't eat anything. 50% ethanol sure will. > Actually, 100 percent ethanol would be fine.....It is Methanol - methyl alcohol - that eats aluminum. |