mikeh

Do you know who supplies fuel to Costco?

ARM

No, I haven't seen any tankers. I will ask an attendant and let you know.

There are only 2 grades 89 and 91. Are they required to identify ethanol content if there is any % present? Also, what is the detriment to using fuel with ethanol content, it seems a real negative in this thread?

cheers

AR

mikeh

When you go to the gas station and choose 89 it takes it out of a tank. When you choose a higher grade the pump blends the two grades to get what you want. 91 Octane is usually kept in a different tank. Octane will not improve gas mileage it is simply the anti-knock characteristics of that fuel. What gas companies do to increase their octane level is add ethanol which is a vegetable based alcohol usually from wheat or corn. It is believed that ethanol does have certain deterioration characteristics that are not good over a long period of time. Ethanol contains less energy in a gallon than gasoline, so theoretically you do not get better mileage using 94 octane over 91 octane. I understand that Costco will purchase their gas from whoever is local to them which means you could get any brand. I would have to check but I am sure they do have to post if they are using ethanol in the fuel.

ARM

Actually you response made me realize, I believe I am in error when I say 89 for regular - it is no doubt 87 octane. Sorry about that. I will also look at the premium to see if it is indeed 91 also.

AR

rocco_ca

I've been using Costco 91 , and the Q5 runs very well.

Mike, are you sure Costco gets their gas from any company who is local? How did you get this info. ? Just curious..

mikeh

Google for the information, but it is not uncommon to see shell trucks at Pioneer or Sunoco truck at Costco. Because of the strict government regulations the gas is the same. Where the difference come in is difference gas companies will add different addatives to the base fuel. So if Costco gets their fuel from different companies depending on location and price you are not always getting the same addatives when you fill up. Yes you are getting the same octane and base gasoline but still not the same everytime. When fueling at Shell, Sunoco, or Petro-Can you can at least be assured that you are using the same addatives since they opperate the refineries.

ARM

Just as an update to my last post, Octane is 87 and 91. I asked the attendant who supplies their fuel - he says OLCO, and added the 91 is free of ethanol.

Price this morning was $1.059 for premium 91 - mileage is 37.3 litres for 544 km. = 6.86 per 100/km.

cheers,
Alan

mikeh

Thanks for taking the time and updating us. The 91 sounds like a bargain.