Does anyone have any thoughts on this in regards to engine components , fuel tank, fuel sender, etc. longevity?

Shell only for me.

There are only a few companies that actually get and refine gas. These gas stations just buy gas from them. Thus most of the gas is going to be the same.

Costco last 12yrs.

same....Costco only for nearly a decade (and see the list of modified/tuned cars we've had.....tuned for 93oct). I recently had to get Citgo on a road trip and my idle was ROUGH. SO HAPPY to fill up at Costco again last Friday.....car is back to normal.

The other thing to keep in mind; Costco sells SO much gas, they get daily deliveries. That means the gas isn't sitting in a tank for a week at a time, letting any residual sediment collect at the bottom. The old rule about NOT refueling at a station that's getting a delivery is a good one (sloshing in the tank and mixing up anything at the bottom); but at Costco, its not relevant.

This is only partially true. Gas is also treated with additives and detergents that differ from company to company. Chevron has "Techron" for instance which is a great injector cleaner. The additives help your car run healthier and cleaner. For me, I try to get to Shell whenever I can.

Costco or SAMs do not have these gas additives, so in the long run it is not good for the engine. If you plan to keep your car for many years, you may lose more than you gain on the gas price difference.

Costco and such also do not have the highest octane number gas. If your engine has a high compression ratio and requires premium gas, you may hear "knocking" that is not good for the engine, because the gas ignites due to pressure and pushes the piston down while it is still going up. This reduces the power, gas mileage, and engine longevity.

Test your gas mileage. If it is the same with Costco gas, you should be fine. Otherwise chances are you are losing more than saving and not only on gas.

If your car requires premium gas, the rule of thumb is to go with the highest octane rating. Here in Kansas City it is BP with 93 vs. 91 at Costco.

I use Exxon and Shell for 5 years now.. Used 93 octane on my M3's and my STi.. Never had a problem.

Sweeping generalizations. Here in Atlanta 93 is available at Costco and what evidence can you provide that absence of unspecified additives "is not good for the engine"

I wouldn't say "not good" but I would say "not additive to maintaining your car". The additives that are absent in cheaper gas go a long way to keep your fuel injection system, your spark plugs, and your combustion chambers clean and running strong.

http://en.wikipedia.org/wiki/Top_Tie...rgent_Gasoline

In fact I'm going to dump a bottle of techron in my car next time I gas her up.

Chevron for me with 50% ERC 101 full time

this.

I just got 26mpg on my car on a road trip from VA to NC. More than good for a big V8 and auto transmission, loaded with three people and junk.

Costco here in VA has 93. I reset my tripometer every time and when its time to fill up, around the same mileage. I do put in BG44k or Technron every other month.

I've used costco many times before and have not noticed any worse gas mileage. I tend to alternate between costco and chevron though, whichever one is more convienient for me when my tank gets empty.

+1

I waste more time than it is worth waiting in line at one of those warehouse stations. Lines are out to the street for what? To save pennies which will never add up enough to justify the wasted time. At least for me. Any of the large premium chains for me with no wait. I will pay the extra .20 a gallon to get in and out.

chevron 94 octane only for me... yes in Canada we get 94 octane :P. Shell gas is the worst out of them all up here, it's been known to kill people's fuel pumps. I even noticed worse performance when I filled up at Shell once... so I stick to Chevron

Same.


Not to mention the Costo/Sams fueling stations are pretty far off the beaten path, with many speedbumps between.


I will happily pay an extra .10-.20 to not have to deal with lines, going out of the way, and speedbumps. Mainly speedbumps.

It's all the same. I grew up in the oil industry and my father is a former exec at COP and current Global Manager of Hydrocarbons at a separate company so this came up at dinner a lot growing up

Personally, I've been using Costco [93] forever, but if I'm not near a costco I go to whatever is closest.

But valero, exxon, shell, texaco, or a murphy oil distributor all sell you the same stuff.

As for your detergent argument, whoever mentioned it... it's been government mandate since 1994 to add detergents to ALL gasoline.

Local station literally opened 12 months ago and we watched them install those massive tanks. Brand new tanks = no junk in the gas (or not much).

It's all locally made around here anyway at the local refinery so it's mostly the same stuff.

Due to elevation, no 93 here. Tuners claim I am overkilling it even with 91 with my DA (6500ft in summers) but I will just take my chances.

I've never had any issues with using Costco gas the last decade or so. Not to mention, one is about 2 miles from my house, so I got that going for me.

Chevron only. Whatever you use, just don't use Arco.

Any thoughts on Sam's Club gas? I like using Sam's since I can use my credit card at their pumps for cash back.

I had to put 93 gas on Liberty, good lord my car was freaking out. I put only shell, worst case scenario Exxon

sams and costco no problems --- only had a idle problem twice after using 76 -- So, I dont use that station's gas anymore.