Amazing how any thread on any topic, however non-controversial, can degenerate into insults.

The Internet is hurtful.


^^^ (Just realized he put 87 in his Vette by mistake)

 

Have to correct myself on what I said above....Not paying attention, and now I do....Want to thank Mr. Bill for bringing my erroneous statement to my attention!

Almost (Maybe all??) all the gas stations here in Reno, ***DO*** carry 91 octane fuel. Of all the stations I have checked, I haven't found one yet that doesn't. Sorry for misleading anyone!

MC

 

This is interesting for me to read this subject!! I work for a top tier oil company and we make a lot of fuel and supply different stations all refiners do this we mix the different detergents at our truck loading rack depending on where its going, Shell / Chevron / Texaco, its the same standard gasoline blend for all, we have a winter blend and a summer blend and we have to lower the octane, i always buy the middle grade its really just the same as super 91-93 octane its left over premium that we sell at alower price so we don't have to keep it in our tanks, i would recommend that you always buy top tier fuel there is a huge difference with the additives we make these day's.

 

I agree with the comments about additives and top tier. I have made many similar posts myself. I do not understand the comment about lowering octane. Where and how? The terminal? The refinery? By blending some regular into premium? Doesn’t sound like anything I’ve ever heard about. Gasoline is normally blended to a target octane at the refinery. If it’s an ethanol blend, the ethanol is added at the terminal, but the refinery blends to an octane which will result in the target final octane after ethanol is added. I have not heard of any intentional octane lowering.

As far as what you get when you buy mid grade, there are 3 possibilities. The least likely is that you really get premium. It does happen sometimes, but it is rare. The most likely is that your gas station has what’s called a blend pump for mid grade, which means that the station has storage for two grades, regular and premium, and the mid grade blend pump sucks some gas out of both tanks in a pre-set ratio so that you get to mid octane by blending regular and premium. The third possibility is that your station has storage for three separate grades, and the mid grade was blended to that grade all the way back at the refinery. I suppose it’s possible that the “octane lowering” comment means that in the area where AR8007 works, rather than getting mid grade from the refinery, the terminals in his area only get regular and premium, and then for the stations that have three storage systems, they blend some mid grade at the terminal. In any event, you should certainly not buy mid grade under the assumption that you are getting 91 or 93 octane. While that might happen once in a while, it would be rare, and certainly nothing you could count on.

 

The warmer the air, the less dense it is which effects performance.