Chevron, Shell, 76, or Costco

I often go to different brand stations, all top-tier though. Is it bad to mix brands?

 

NO.
Did you READ the post about it all coming out of the same pipeline ???????
I don't think there are any refineries near your area.
Even if there are, the answer still is NO, it's fine.

 

...if you have some gasoline distribution experience, maybe you know more than me. But I assume there could be differences in (energy contents) between EPA RFG regions and regular/premium etc.

 

Until you start mixing in stuff like ethanol, any "energy content" differences are miniscule.

And you don't have to be a petroleum engineer to know that.

 

The truth is that the mixture of chemicals in gasoline can vary enough to get different mpg's and often high test gas will yielfd higher Btu per pound than regular because the components needed to combat knock. But the difference brand to brand doesn't change enough to see it except on heat of combustion testing. And while high test will generally yield a little more heat of combustion when you do the statistics its not that much greater to justify the cost. Unless of course the high test doesn't have ethanol and the regular does, which seems to be the case a lot.

I do have petroleum refinery experience and the pipelines do not connect with a single refinery. Sure they all are transported in single pipelines but in batches not as a single mixture though there is some mixing when changing. But there isn't much difference except between octane levels and yes most additives are added at the bulk stiorage tank farms when the gas is loaded into trucks for distribution. If that has changed, and the drive for reducing gas costs is severe, then you may right about differences being meaningless for branding but not much else.

 

Top tier gas is the same as cheapo gas, except for the additives.

The goodness in top tier is the abundance of additives. Otherwise the base gasoline is the same, and a commodity like soy beans.

Top Tier Gasoline

What really matters is the station's gas turnover, age of the holding tanks.

If you can find a cheap station that has fast frequent turn-over, go there, and to make up for the lessor additives, just drop a bottle of Techron in the tank every 3,000 miles.

 

I use Top Tier gasoline. No exceptions. Better additives.

 

....me too that's all I use...and the list of TopTierGas.com stations seems to be growing...now inlcudes BP and Costco which must be relatively new additions. We have a lot of top tier here (high gaso price area) so it's easy to use them.

...I think we are in agreement.. I am not saying everyone has access to higher energy content gasoline. I am just saying some might have access, in some regions, possibly in E0 for example. EPA seems to use a high energy content test fuel, and I heard a gas station at race track in WV sells it...maybe I try it someday. Chevron stresses that in RFG regions (my area) there is no energy content difference between Reg/Premium. Also of course when the summer fuels comes in, that will be a energy content shift. Right now I am measuring 0.72 density and I will check later to see density shift when summer fuel comes in.

 

Here is an interesting map of US Gasoline Requirements.
http://www.api.org/~/media/Files/Policy/Alternatives/US-Gasoline-Requirements-Map.pdf
Below I show a screen shot capture (use above link for better resolution).

What I am looking at is, significance to Prius owners: where might you see some gasoline MPG differences?

• When I go from DC region to Pittsburgh, I am going from Southern RFG blend to a 7.8 RVP area. So the 7.8 RVP might imply more energy content...we shall see. Some of you (NC, GA, FL, etc) are in 7.0 RVP ...maybe a little more energy yet.
• Re: Ethanol - Note the few blue states are those that mandate 10% ethanol. That is a semi-meaningless right now because the whole country is at E10. But it's not quite meaningless, because apparently smaller oil companies are not mandated to put in the 10% ethanol (in states like VA). So that means some people can get E0 - ethanol free - at 87/89/or 93 octane (eg; on I-81 in VA). Bet that stuff might be quite higher energy content than the RFG stuff I that have to use (see Pure-Gas.org to find E0 stations).

 

I always go to 76... because I have their gas card.

 

Finally Costco is on the list.

Now you just have to wait in the 30 min line.