How to fill up your vehicles
2) Right, but that 10% is also with a temperature delta of 180 degrees.
30/180 = 16.6% so, take that to your 10% => .1 * .17 = 1.7%
Insignificant, especially given that ground temps don't change at the same rate or by the same delta as the air temperatures and we assumed, likely incorrectly, that the density shifts linearly with the temperature. More likely the colder you get the smaller the density delta.
This is a ridiculous myth that has been perpetuated by people because they think it really is going to make a difference and it is actually based on the properties of physics. Quantitative analysis easily shows it isn't worth fretting over, or getting out of bed early on a Saturday morning.
Last edited by CrashTECH; Apr 13, 2010 at 05:27 PM.
Sorry, but that list has been circulating for years. While it isn't really a scam it is kind of misleading. Most likely from someone who needs to feel important by having their stuff spread over the net.
Really the main thing to remember when filling is don't spill it on your paint
Really the main thing to remember when filling is don't spill it on your paint
Ethanol is less energy dense than gasoline, and as a result is about 20% less efficient per gallon. Run the same engine (ignoring other issues with running a standard gas engine on straight ethanol) and the ethanol version will have about 20% fewer mpgs. However, ethanol is something like 104 octane, so engines built for ethanol could have higher compression.


