Fuel brands revisited

I previously bought primarily Shell gas b/c I had a rebate card that gave me Shell Gas. I got a new rebate card....so I get 5% of any gas...not just Shell. Soon afterwards I started complaining about a drop in my fuel economy. I have found Shell gas to give me 2-3 mpg more than my Sheetz tanks. My father swears Texaco is even better than Shell, but there isn't one I pass frequently so I cannot confirm it in the Prius.

I stopped buying Mobil when they merged with Exxon. At that point I was driving my dad's 1996 Ford Ranger....and if you put Exxon in it would rattle like crazy. Any other gas, no rattle.

 

I usually always get gas at BJ's and usually get 48-50 mpg

 

I regularly get my gas at either Chevron or Arco or occasionally even Shell or Mobil, depending on which one I'm nearest to when I decide to get gas. I've never gotten a full tank (ie: 400 miles or more) averaging less than 47.8mpg which also happens to be my lifetime average, go figure. I'm pretty sure the gas in CA doesn't have the ethanol blend like I know a lot of the midwestern states have been getting, so we don't have that to worry about (yet?).

 

No difference. I drive 1k per week and have tried many brands and grades with no difference noticed.

 

During my first year of ownership I used BP and Exxon almost exclusively. Those were the only "good" gas stations around. I didn't feel comfortable getting gas from a no-name gas station. Now that I'm in a more urban environment, I use whatever is close by. Wawa, Sheetz, Chevron. But not Citgo. I noticed about a 3-5mpg hit when I used Citgo gas for about 4 consecutive tanks.

 

i use either Arco or Costco both with 10% ethanol mix (cant buy anything around here without it) only because they are the cheapest.

safeway started this purchase $50 and get a one time fillup with 10 cents off (that usually makes their gas a few cents cheaper than Arco) my so my SO uses them.

there is no real difference in unleaded regular anyway. so if you are spending a penny more for brand name gas, you are wasting your money. the biggest thing to look at is how the station you go to is maintained. poorly maintained stations also probably have gas storage tanks that are not maintained properly either. that will cause more issues than any brand will

 

I use Arco, largely due to price and convenience (most of the stations closest to our house are Arco stations). In CA, at least, they're owned by BP.

 

After driving for 8K in Phoenix, I've observed the following, driving the same roads in a similar weather:

Shamrock - 57-61MPG
QT - 55-58MPG
Costco - 49-53MPG

 

Gas is gas. The ethenol content causes more of a difference then the brands do. Gas comes from the same pipelines and while there are minor additives they don't amount to much.

A poorly run local station could have impurties in the gas but thats quite rare. I have noticed no difference in mpg regular vs premium or brand to brand.

 

I know that several car manufacturers (I think, Toyota, BMW, Honda & GM?) got together with some fuel companies and asked them to adhere to some guidelines regarding detergent additives for their gasolines.
I believe Shell, amongst a few others that I can't recall, agreed to this standard.
These companies are suppose to have the "cleanest" gasolines.
If anyone knows the other companies beside Shell, please post.
Thanks
mfc

 

<div class='quotetop'>QUOTE(MyTFineCar @ Sep 8 2006, 10:22 PM) [snapback]316810[/snapback]</div>

According to http://www.toptiergas.com they are

QuikTrip
Chevron
Conoco
Phillips
76
Shell
Entec Stations
MFA Oil Company
Kwik Trip/Kwik Star
The Somerset Refinery, Inc.
Chevron-Canada
Aloha Petroleum
Tri-Par Oil Company
Shell-Canada

Chevron, Shell, and 76 (part of Conoco Phillips) are the only top tier sellers around here. I stick to these. Prior to top tier I stuck pretty much to Chevron because I felt Techron was the best of additives - I am biased here as a formerChevron employee (in the interest of full disclosure). But ask people that actually tear down engines and most will tell you that they can tell who uses cheap gas - most mechanics I know don't use grocery store gas.

On an almost exclusive diet of Chevron our Dodge Spirit went 187,000 running fine (transaxle died so we shot the car). My 1995 Explorer was still passing smog tests and hadn't lost 1 MPG of efficiency at 203,000 (the air conditioner and front differential died very close together - car euthanized.) My Hyundai was running fine but suffered a premature death at 57,000 miles when I committed vehicular sodomy upon a Ford Ranger on interstate 80. That incident moved my Prius purchase schedule up.

I stick to fuel with known quality additives and shop price among them. Around here Chevron, Shell and 76 can differ by as much as .05 per gallon.

 

I have heard that adding 10% ethanol to gasoline will reduce your mileage by 10% because ethanol has less btu's per gallon.(Can anybody confirm this?)
So say you are getting 50mpg on gas at $3.00/gal and you switch to 10% ethanol at $2.90/gal and now you are getting 45mpg(10% less) and you are traveling 400miles. How much are you saving?

$3.00/gal x 400mi/50mpg = $24.00 (cost of trip on gas)
$2.90/gal x 400mi/45mpg = $25.77 (cost of trip on 10% ethanol blend)
$2.85/gal x 400mi/45mpg = $25.33
$2.80/gal x 400mi/45mpg = $24.88
$2.75/gal x 400mi/45mpg = $24.44
$2.70/gal x 400mi/45mpg = $24.00

In this example, the 10% ethanol blend has to be 30 cents(10%) cheaper than gas to equal the same cost per mile.

 

If 10% ethanol blend gets 10% less gas mileage by the logic that you have heard, that means essentially ethanol would have had no energy content at all, which is not true.

About 2-3% I believe is an accurate number. The 10% number came from E85 versus gasoline.

The plus about ethanol is that it's from renewable resources (although it takes a lot of electricy to produce, and power plants could burn NG or coal), but it does burn cleaner.

<div class='quotetop'>QUOTE(bernzx @ Sep 9 2006, 02:38 AM) [snapback]316872[/snapback]</div>

 

The energy content of MTBE is about 93,500 Btu per gallon and the energy content of ethanol is 76,000 Btu per gallon, while that of conventional motor gasoline is about 114,000 Btu per gallon.

I believe that a “real world†study to examine the impact of reformulated gasoline on fuel economy showed a 2 to 3% decrease in mpg that could be attributed to using reformulated fuel. That study is: “On-road study of the effects of reformulated gasoline on motor vehicle fuel economy in Southeastern Wisconsin, Wisconsin Department of Natural Resourcesâ€. The EPA also suggests that RFG will reduce fuel economy by about the same amount. That URL is:

http://www.epa.gov/orcdizux/rfgecon.htm

For many of us, the discussion is of academic interest only. We live in parts of the country where RFG is required and it is the only game in town. The question is of greater interest, perhaps, to those folks who can use E85 versus gasoline. How cheap would E85 have to be to compensate for the drop in fuel economy?

 

Don't think because you drive into a gas station branded or otherwise your getting their brand. Most gasoline is delivered to stations by wholesalers and you have no way of knowing where their stock came from.

Case in point. I get some of my gas from a Shell station near me. I was driving by one day and there was a Union gas tanker dropping it's load into the Shell tanks.

That being said my guess is that most stations deal with the same wholesale companies on a regular basis so the relative quality of the product sold by a particular station is hopefully consistent.

 

<div class='quotetop'>QUOTE(vkykam @ Sep 9 2006, 10:26 AM) [snapback]316944[/snapback]</div>

No, I think a 10% reduction in mileage for ethanol in a 10% ethanol blend means you would get a 1% reduction overall (10% of 10%). This might be flawed...I'm not a mathmatician.

 

Coincidentally, I have been experimenting and testing different gas from different vendors.

In this experiment, I got my first tank at 76 and averaged 48 MPG, the second at Chevron and averaged 51, the third at 76 again and averaged 47.6, this tank is from Chevron and so far I'm at 50.6. Weather and driving have been about the same through all tanks. It seems I get better MPG from the Chevron gas.

Prices are still up around $2.86 here in blue Oregon where we require professionals to fill our tanks, but the prices are about the same in Washington, where you pump your own (Ah, don't you just love the smell of gasoline on your hands!).

The problem, as I have said before, is that we buy gallons, not energy. Temperature, alcohol content, and who knows what else affects the energy content of a gallon volume of "gas". Still, my Silver Cloud is more fuel efficient than any other car I have owned, so I'm happy. For now.