How do we know we are getting premium gas when we pay for it? - PeachParts Mercedes-Benz Forum

ohiomike · #1 09-18-2009, 04:35 PM

It is my understanding there is both basic gasoline and alcohol lines connected in a gas pump. When you push or select "premium", the pump just mixes more alcohol into the basic mixture. The same goes for mid-grade. The content of alcohol in the fuel determines the octane.

pawoSD · #2 09-18-2009, 05:12 PM

Quote:

Originally Posted by ohiomike

It is my understanding there is both basic gasoline and alcohol lines connected in a gas pump. When you push or select "premium", the pump just mixes more alcohol into the basic mixture. The same goes for mid-grade. The content of alcohol in the fuel determines the octane.

I would think that type of system would be way too risky. If the pump malfunctioned it might dump pure alcohol into your tank vs. a mix....with bad results.

I am pretty sure the stations at the very least have a tank of regular and premium and the pump might blend those to make midgrade.....and I bet many stations have separate tanks for all three.

lkchris · #3 09-18-2009, 06:03 PM

Best way to evaluate is to speculate how badly you feel the seller wants to remain in business. And avoid being sued. And staying out of jail.

pawoSD · #4 09-18-2009, 06:07 PM

Quote:

Originally Posted by lkchris

Best way to evaluate is to speculate how badly you feel the seller wants to remain in business. And avoid being sued. And staying out of jail.

Which might actually mean the independent operators play by the rules more closely than the corporations, because they don't have the "ability" to deflect issues with the law like the big guys....

Interesting....

tivoliman · #5 09-19-2009, 02:06 PM

As I understand the local station manages Gasoline (three grades) is that they have two grades in the ground, and mid grade is a mixture of the two.

I got a bad tank of gas once at an independent - water or something - much grief and new catalytic converter later - I have never gone back.

The guy remains in business. So I'm guessing his cheap prices make a difference.

Those were the days I would drive 200 miles a day, just to get to the office, so buying gas was a daily event.

Guess this is another reason to buy diesel - though diesel bigots have told stories of bad gas stations. With diesel, it's usually all the same grade.