Sam's Gas MPG

So I've been tracking my MPG and watching how I drive in the past few months and I've noticed a trend. Typically I fill up at Hess but if I'm passing Sam's Club I'll stop in and fill up, it's typically .08 - .10 cents cheaper than anywhere else.

The three times I've filled up at Sam's since I've been tracking it I've noticed I get at least 1 - 1.5 MPG less in two different vehicles.

Anyone else notice this or am I just being overly suspicious of the cheaper price?

 

driving habits have a lot to do with it too. even an hour in a week of heavier than normal traffic can tank your mileage.

I would fill up at sams for at least 7-10 fillups and then compare it to your usual station to see if that makes a difference. I think fuelly will do it for you if you sign on.

 

Its funny you noticed that....I noticed the same thing. I even changed octane, and noticed a 1 mpg gain in 91 vs. 87 (Sams Club)...but when using 91 at Chevron I get 1 MPG better then Sams. So, the way I figured it, you end up spending the same amount of money either way....less gas mileage = cheaper gas...or slightly better gas mileage = $.08-.10 more per gallon.

 

In previous vehicles I noticed that. I had an 89 toy 1/2ton 2wd that loved texaco but hated am/pm. Would take shell and chevron all right.

A friend recently asked me about the gas mileage in her 2009 altima cause she noticed the same thing. never could find an explanation for it other then maybe the additives in the gas.

 

+1

I tracked gas usage for a period of 6 years on the same vehicle, and never found any statically significant differences in gas mileage. All the gas in my area comes from the same refinery, so I thought maybe the additive package would make a differences for the Top Tier brands in my area (Chevron & Shell) when compared to the price leaders (Sam's, Hess, Racetrac, etc.). Nope -- Surprisingly, the very best mileage I got, that I couldn't attribute to difference in driving (hiway vice city) was a fill-up from RaceTrac.

This is not the same as saying the additive package of one brand is the same as others in cleaning valves, etc. That I had no way of testing.

My guess is that pumps at one brand vice another are set to kick off as "full" earlier than others - so you can only tell if you purchased gas at the same station over a longer period before switching to another brand (like o5iiawah suggested). My WAG for why this difference might exist is each company having their own tech setting up the pumps across an area.

 

I first noticed this on my motorcycle over the course of 3 years i tried every gas station near me. The cheap non brand name gas stations got me 90-100 miles per tank. ampm got me 105-115, shell and texaco got 120-130 and chevron got me 145-155. huge differences considering the prices really aren't that much more. Everyone I know goes for the cheapest grade gas, at the cheapest station they can find and thinks I'm crazy for stickin with chevron...

 

Ever notice unmarked tank trucks in gas stations?

 

My opinion is that your driving habits are the reason, not the gas.

This is certainly true where Sam's Club fuel would be concerned. As one who has represented "big oil" and all of its industry segments for the past 14 years, if there is one thing I am certain of, the fuel recipe is not gonna account for a change in MPG's along the lines you are seeing unless you are switching from SoCal summer mix to mid-west winter mix (or something similarly divergent). Fuel stations in the same region sell and market the same federally or state regulated mixtures. Hell, I've handled transactions where branded station X sells its fuel to branded station Y for sale in Y's tanks. (eg: Y sends its own truck to X's refinery, fills up and then travels to a Y branded station to dump it into their tanks. Customers never know the difference.)

Wal-Mart (Sam's parent co.) is certainly purchasing its fuel from one of the big branded refiners.

 

Winner!!! Pay the man his prize.

 

Thanks for the positive responses. I'll keep tracking as indicated in previous posts.

And GuapOh, thanks for the input, not trying to be a dick but the comment assumes a lot for someone who doesn't know me. And, please if you are going to make comments like this, please for the love of God, understand the difference between "your" and "you're". To quote you, in my opinion it's your grammar, not spell check...

 

I found COSTCO gas also causes a drop in MPG. I try to run BP or Shell

 

I get a mileage drop like that when buying at certain stations, I am convinced it is because those stations are using ethanol. In Ohio they don't have to tell you if they are using that crap. I have learned where the non-ethanol stations are, by checking mileage, and that's where I go now. I see from fuel-testers.com that Florida does require stations to label ethanol, so OP are you buying ethanol when you get lower mileage?

Calculations for my truck show ethanol gas would have to cost 20 or 25 cents per gallon less just to break even on the lower mileage. Any less of a discount and it ends up costing more miles-per-tank wise. Corn lobby rip off.

 

Generally speaking, gas is gas... recently I ran Safeway gas and got the same fuel economy as I get with ARCO AM/PM product (which is what I normally run), and I always drive like a pussy with a mix of 70% hwy/30% city. I've even messed around with Shell and Chevron and Unocal, none of it makes any difference in my truck. Yes the additive packages differ but not enough to cause a significant mpg effect in the short-term.