Quoting "Klebert L. Hall" <swampyankee@xxxxxxx>: > In the winter, most gas stations use a different formulation of gas that > vaporises easier in cold temperatures. This tends to give lower gas mileage, > partly through increased evaporation. The main reason why you see lower mileage with higher volatility gasoline is its carbon to hydrogen ratio is lower, thus less energy content (see my prior post). If you have holes in the fuel lines, then evaporation could take its toll I guess too :) > > The oxygenated fuels with ethanol or MTBE shouldn't give lower mileage in > an older Imperial. The problem here is that modern cars generally have > oxygen sensors. When oxygenated fuels are burned, they're supposed to lean > out the mix for cleaner burning (by carrying oxygen into the combustion > chamber in the gas to add to the oxygen in the air). Unfortunately, the O2 This does not seem to add up. If the oxygen in the alcohol affected the O2 sensor, then it would also add more oxidizing oxygen which would burn off the claimed excess fuel and produce more torque for the same throttle position. The reason the oxygenated gas reduces mileage (and performance) is that alcohols have reduced energy content, especially methanol with only one carbon atom. All engines are effected. D^2 ----------------- http://www.imperialclub.com ----------------- This message was sent to you by the Imperial Mailing List. Please reply to mailing-list@xxxxxxxxxxxxxxxx and your response will be shared with everyone. Private messages (and attachments) for the Administrators should be sent to webmaster@xxxxxxxxxxxxxxxx To UN-SUBSCRIBE, go to http://imperialclub.com/unsubscribe.htm