e-man

I've been buying gas at Costco for about a year now (for my 98 GS4). It's considerably cheaper than at the local gas stations in the area, so I figured why not. In fact, during the height of gas prices last summer, it was about 25 cents cheaper per gallon (for the premium 93 octane). Now that gas prices have come down a bit, the price difference is only about 10 cents per gallon, but it's still a savings of a couple of bucks, so I've continued to fill up at Costco. For the past 6 months or so, I've been keeping close tabs on my gas mileage. I travel 30 highway miles to and from work with some local driving as well, and, on average, I've been getting about 20 miles per gallon. If I slow down on the highway from 75 to 65, I get closer to 21 mpg. Anyway, I would say that I've been getting pretty much 20 mpg for quite some time now.

I let my wife drive my car last weekend (I know -- big mistake), and she noticed that I was really low on gas so she filled up at the local Shell station (with premium -- good girl). For the last week, I've been running late pretty much every day and I've been driving relatively fast on the highway around 80 mph), accelerating hard at lights, etc. Anyway, I just filled up my car yesterday and to my surprise, on the last tank of gas, I got 22.5 mpg, approximately 2.5 mpg better than most tanks for the last year. This CANNOT be a coincidence, particularly because I was really driving with a heavy foot on this last tank. I've have to believe that the Shell gas burns much cleaner and more efficiently than the Costco gas. Sure, you save a few bucks per tank filling up at Costco, but if this last tank is any indication, you get much better mileage on "brand name" gasoline, so it probably all works out in the end.

Anyway, I thought I'd share. Has anyone else had this same experience?

e-man

varcity64

iTrader: (2)

i cant say that i have any experience w/this b/c i NEVER put that garbage gas in my car, only the best... all i know is that you get what you pay for

e-man

Costco has a good reputation, and I really I didn't think it would sell bad gas to its customers. I don't know if I would go so far as to call the gas "garbage," but clearly it's not up to par with Shell and possibly other brand name gasolines. And, you are right, generally in life you get what you pay for, and this is a perfect example.

GSquicksilver

i've noticed that too. i usually fill with either chevron or 76 and i get like 20-21 miles per gallon. when i fill with costco gasoline, i get like 18 miles per gallon.

GlobeCLK

iTrader: (5)

the only garbage gas is Arco.

HD-GS4

It's funny how some people think they're saving money by using cheap gas, as well as cheap dyno oil.

If you run your car on good Chevron gas, and run it on Mobil 1 fully synthetic oil it definitely feels more expensive at the cash register... but in the long run, it is about the same price, and you get the added benefit of of a cleaner, longer lasting engine. These same people that run junk gas and oil in their cars, also tend to buy Fords "and other fine cars", as the rental car companies say. Buy yourself a nice car, keep it well maintained, and use good quality oil and gas, and you'll get ahead. The rich definitely DO get richer...

morris

iTrader: (2)

Somebody tell me what constitures Junk Gas?

e-man

That's a really good question. Seriously.

nthach

my car gets OK mileage on Costco and Chevron gas, good mileage on 76 or Shell.

nthach

In California, all gas is the same CARB RFG II with alcohol. It's the add pack and how the fuel is stored and shipped that is different. Shell(SOPUS)/ChevronTexaco/ConocoPhilips(76) have their own add packs. Generic fuel uses standard off the shelf Ethyl, Oronite or Lubrizol add packs.

morris

iTrader: (2)

dude I'm not a petroleum engineer break it down for the little people, whats and add pack any way

Then the next Questiopn w0ould be is that just a CA thing then?

nthach

add pack=additive package, Chevron's Techron is an example of one

Reformulated Gasoline is used in places that have bad air quality like California in an attempt to reduce air pollution. It's a standarized formulation with a oxygenate like MTBE or ethanol added to it.

PhantomZX

You don't really save much with Costco gas - get a Citibank Dividend card and they'll give you 5% cash back at gas stations. $2 per gallon at 5% is $0.10 per gallon you're saving by using the card. The trick is to only use the Dividend card on Gas and Groceries since they have a $300/year cash back limit.

jonathancl

Octane just refers to how much heat the fuel will withstand before it combusts of its own accord (knocking).

It doesn't say anything about its ability to make your car go.

Right?

URWTDRM

What is this 93 octane you speak of? We only see 91 octane out here