Good point and I always try to fuel up at newer outlets as less chance of getting contaminated fuel then a 30-40 year old outlet.

Good info on Costco, I've never purchased gas there as it's just not convenient for me.

 

I have ran Costco (top tier) gas in all my vehicles for many years. It' been $1.35 per gallon for at least two weeks here.

 

$1.35 per gallon?


Wow! I want to move there.
😁

 

Whoa there……I meant $2.35 per gallon!

 

• I have run Costco gas for decades in five different cars with zero problems...
• Periodic experiments with gas mileage yielded no distinguishable difference between Costco and "name brand" fuels.
• Finding a convenient Costco and its low traffic time (usually before the warehouse opens in the morning or later at night) and using the Costco Visa card keeps more money in my pocket.

 

Sure, if it's convenient. I just wouldn't want to live that close to a Costco and using up a couple of gallons to drive there and back at exactly the right time to avoid lines is not exactly cost-effective. Plus, you have a membership fee. I do not find shopping at Costco a pleasant experience. I'd rather drive right to the pump on the Rez and support the local tribe instead of the megacorp.

 

I live in Colorado and work in Georgia; have a Costco within 5 miles of both my home in Colorado and apartment in Georgia. I have never waited over 5 or so minutes at either..with that having been said, I usually gas up there when I was going to Costco to shop/browse/snack anyway. I do find it to be so wrong to fill up my Ford Fusion (tuned) with 93 octane in GA, while my cars in CO have to drink 91 octane.

 

I refuel at the Costco on the way home every Monday night after meeting friends for our "begin the week right" get together... Easy peasy...

 

Is that for 87 or 91?

Here in Springfield, Top Tier Philips 66 is $2.29 for 87 and $2.72 for 91.

 

In Colorado (at least around Denver), the pump octane rating is lower because the air is thinner. I was out there with my son back in October and noticed that "regular" was 86 octane, "mid-grade" was 88 and their "premium" was only 90 octane.

Nonetheless, my rented Nissan Sentra made it all the way to the top of Pike's Peak (~14,100 feet) on a tank of 86 octane unleaded regular....but it sure was struggling to do so.

My guess is that the lower octane has to do with no humidity, altitude, leaner air/fuel mixtures, ignition timing and myriad other peculiarities.

 

Pumps open at 6 AM on Sat. and Sun. No waiting. I fill the car and my gas cans. My drive to work is 70 miles each way. Daily driver is a Honda.

I use Costco and Chevron in my C7.

 

Some of the towns/cities in Colorado that have 91 or higher....

Almont
Berthoud
Brighton
Carbondale
Colorado Springs
Commerce City
Cortez
Craig
Crestone
Divide
Englewood
Fort Collins
Fruita
Glenwood Springs
Granby
Grand Junction
Grand Lake
Gunnison
Hotchkiss
Julesburg
La Jara
Lake City
Lake George
Lakewood
Lewis
Littleton
Longmont
Loveland
Mancos
Meeker
Montrose
Nathrop
Pagosa Springs
Parachute
Pueblo
Rifle
Silt
South Fork
Steamboat Springs
Sterling
Twin Lakes
Vallecito Lake

These towns/cities have stations that sell ethanol free 91.

There are plenty of others that sell 91 E10.

 

Actually, it’s not that complicated, it’s pretty much all altitude. Yes, things like temp and humidity matter a bit, but that’s not what’s causing the big shift. What mainly matters to the engine is MAP (manifold absolute pressure), which indicates how much air is getting into the engine. At sea level with wide open throttle, MAP is close to standard sea level atmospheric pressure of 14.7 psi. There’s a tiny bit of pressure drop across the air filter and through the intake manifold, but not much. However, if you go to Denver at 5000 feet altitude, atmospheric pressure is only 12.2 psi, or a bit over 80% of sea level pressure. So at wide open throttle in Denver, the engine’s MAP is not close to 14.7 psi, it is close to 12.2 psi. Or said another way, wide open throttle in Denver is like throttle about 80% open at sea level. If you go to the top of Pike’s Peak at 14,000 feet, pressure is only 8.6 psi, or about 60% of sea level pressure, so wide open throttle at the top of Pike’s Peak is like throttle 60% open at sea level.

As far as octane, if you are in Denver, it’s like you are driving around in Houston with a wooden block under the gas pedal which prevents you from pushing it more than 80% of the way down. Since you can’t push the throttle more than 80% down, the engine doesn’t work as hard, or produce as much power, so doesn’t need as high an octane rating. But if you looked at the engine programming, things like timing, air/fuel ratio, etc, along with power output and octane requirement to avoid knocking, would be the same in Denver at wide open throttle as they are in Houston at 80% throttle.

 

Nice list JoesC5. I do have to say that while I see 91 octane premium at every station that I visit in CO, I Have never seen any with a higher octane than 91. . I would imagine that some of the towns that are at lower elevations may well have some that is higher 91.

 

Dallas area Costco is 93 octane. Big fan.

 

Do you need to be a Costco member in order to buy their gas?

 

Yes

 

I use Costco 91 (highest we get around here) pretty much exclusively. Longest I've ever waited was maybe 5 minutes (on average, more like 2 mins), and after a long day at work, I don't mind the quiet time in my Vette

I do have a Volt as my daily so my trips to the gas station are pretty infrequent considering I get ~270 miles per tank in my Vette.

 

93 here in NC is generally over 3 bucks a gallon. Crazy. I remember when it used to be .10 cent between all grades.

 

Not necessarily. You can buy a Costco gift card without a membership. Then Costco gift cards can be used to purchase items without a membership.

I had a friend who was too cheap to pay the membership and only wanted a few things. My kids eat enough that the 2% back more than pays for our membership each year.