Question on gas
On 9/15/11 I purchased a brand new 2011 Ram 1500 Tradesman, with a 5.7 Hemi. Filled up only once so far. Used 89 octane with ethanol. My manual say 87 octane is acceptable, 89 octane is preferred. All the gas stations close to me have ethanol in their 87 & 89 octane gas. But on my way to work, there are a few stations that have 87 octane with out the ethanol.
So, why is 89 octane preferred over 87 anyway? And if I used 87 with out the ethanol, would I notice any difference (less MPG, etc.)?
Thanks for your thoughts guys,