Different MPG with different brand of gas?

Many Prius owner's have made postings that, Shell seem to increase MPG by 1 or 2.

 

Shell is good, but the QuickTrips here seem to be the best.

My theory is whichever gas has the least Ethanol works best. Reason I say that is there is a Kroger here (MacArthur just south of 635 for you DFW folks) that has an E85 pump. They have corn logos all over everything, and instead of just the usual "May contain up to 10% Ethanol", they have special signs that say, "Enriched with 10% Ethanol". Every time I fill up there, my regular QuickTrip/Shell mileage goes from 50-52 down to 44-46. The motor has decidedly less power, and you can see the mileage bar on the Consumption screen struggle to stay at 100mpg even when you let off the gas. First time I filled up at that Kroger I had tried 89 Octane just for fun, so I wrote off the poor performance. Then I next filled up at a QuickTrip - back up to 50mpg. Next tank was the same Kroger, but I used 87 Octane, and again my mileage and performance immediately went in the toilet as I drove off - ended up with a 46mpg tank.

 

<div class='quotetop'>QUOTE(DFWPrius @ May 19 2007, 11:26 PM) [snapback]445952[/snapback]</div>

This happened with my Prius too and it was more like 3 mpg

 

Quicktrips are all over Atlanta. It is usually the best price gas.

 

I used to buy from Murphy Oil ( Walmart) but have switched to shell 87 octane and get 52-53 mpg vs 48-50 mpg with the wallyworld stuff so it's shell for me

 

There is a 5% rebate when the Shell MasterCard is used at a Shell station. So unless Shell is 5% more expensive to begin with, it is the cheapest gas in the end. (The rebate is credited directly to the Shell purchases the next month. Nothing to redeem, no minimum redemption amount.)

 

Interesting discussion... Today I filled up a tank in Scottsdale and by the time I got to my home in Buckeye, AZ (40 miles west) I had averaged 61 mpg on mostly freeway. I've never seen such high mileage on this run before. Some things I did differently this time around:

1. Filled up w/ 87 octane at QT
2. Increased my A/C thermostate from 75 to 85 -- I read somewhere that the A/C in the prius is most efficient at 85.
3. I employed a little bit of N-glide a few times on the freeway where there was a mild downhill.
4. I stayed 5mph below the speed limit for all zones above 55mph (I'm normally 5mph over).

I don't know if it was the gas or a combination of all factors, but I normally average about 46-48 mpg. It was also "only" 90 degrees today compared to 15 degrees higher the previous week.

 

<div class='quotetop'>QUOTE(JimN @ May 20 2007, 07:18 PM) [snapback]446315[/snapback]</div>

I got a shell credit card in jan. of this year and have been using it exclusivly since then.My mpg went up 3 to 5 mpg immediatly.My last two tanks Ive gotten over 57 mpg .Im currently getting 62 mpg after 330 miles! I really think shell makes a difference

 

<div class='quotetop'>QUOTE(PriusBoyAZ @ May 21 2007, 03:19 PM) [snapback]446937[/snapback]</div>

PriusboyAZ, have you tried AM/PM or circle K out there in AZ?
when we lived there I always used am/pm in all my service trucks on the road and got decent milage but have not used a lot of circle k gas wonder if there is a difference there as in shell?

 

I use Arco (owned by BP) normally and tried 3 tankfuls of Shell (one after another). I didn't notice any change; if it was it wasn't that much difference.

 

<div class='quotetop'>QUOTE(aaf709 @ May 21 2007, 05:09 PM) [snapback]446970[/snapback]</div>

Regional differences is one reason why local gasoline testing is important. I'm in N. Alabama and my testing shows Shell 87 has about 11% more energy per unit. However, I would expect east coast and west coast gasolines to be significantly different. Heck, I'm not even expecting consistency across the summer/winter blend changes.

Bob Wilson

 

Another drive to Scottsdale and back, and am still averaging 60 mpg on mostly freeway driving. This time I also made a couple of stops, so I suffered through a couple of "cold start" cycles. Initially I thought maybe the run from Scottsdale to Buckeye was a net downhill run, but yesterday's round-trip has proven that something else is going on.

Could I have gotten an incredible tank of gas at QT? Could it be the increase of A/C temp from 75 to 85? Could it be staying 5mph below the speed limit in zones greater than 55mph? There hasn't been much wind the last few days -- normally it's typically windy in this area -- so that must have contributed to the mileage jump as well.

I'm not complaining, I just think it's interesting how a confluence of factors can cause a 25% increase in gas mileage!

 

<div class='quotetop'>QUOTE(PriusBoyAZ @ May 24 2007, 01:20 PM) [snapback]449308[/snapback]</div>

Yes. It's the only logical answer.

 

I've been filling up (once mind you) at Costco, they use no additives, change their filters and check the octane ratings more than anyone else (check the pump) You can always run into the warehouse and pick a four pack of techron if you want the additives. I've never bought Shell because 1. there are no stations on my normal route, and 2. Someone once showed me pretty clear evidence that shell gas eats seals within the motor (or at least did about 10 years ago)

Y'all haven't dealt with crap fuel until you've owned a direct-injection diesel. Then you learn what a crapshoot it's like trying to find high quality, high cetane, clean fuel.

 

<div class='quotetop'>QUOTE(Les Gas @ May 19 2007, 11:52 PM) [snapback]445961[/snapback]</div>

You are right about the ethanol. It seems that few stations still sell 100% gasoline, most are 10% ethanol. If you live in eastern ohio / western PA the gas at getgo (giant eagle) is 100% and has netted me some 59 MPG tanks.