Fuel brands revisited

I get better mpg with Shell than anything else I've tried. (No Chevron here) And the difference is about 3 mpg from the best of the rest, but can be 7 or 8 mpg better than some others.

I see the difference on every tank, exept one time I did get bad mpg with a Shell fill up. Every other tank my mpg tracks the brand whenever I've been able to notice it, ie no changes in weather etc to swamp out the effect.


Regarding Ethanol I don't buy the tiny mpg loss people claim. I saw more when we got it here, and I expect the effect is more like 4-5%.

The claim is based on energy content only and there are other effects, such as the change in mixture required and the effect of some water for sure being in the fuel too with all that ethanol.

We may be getting on average lower octane too, and I see more spark retarding than I like on acceleration with the canview readout. With acceleration I see the engine retard from 38 to 41 degrees down to 28 degrees. I'd say the best regular I get is borderline ok but some tanks are not as good. I have not been watching ths canview feature long enough yet to relate it to brand of gasoline.

 

<div class='quotetop'>QUOTE(Curtis SAC @ Sep 9 2006, 01:10 AM) [snapback]316838[/snapback]</div>

Thanks for that Curtis.
I was wondering who the other companies were.
Looks like Shell is IT, for my neck of the woods.

 

Being the cheapskate that I am, I've been purchasing my gas at Costco. Over the last 5,700 miles, I've averaged 46.8mpg. Much of my driving is in town and generally under 10 miles per cycle (from power up to shutdown) and usually with minimal hills.

Given what I've read here, I think I might switch to Chevron for awhile and see what results I get. The price difference is generally from 4 to 8% higher, so if I get anything over 50mpg, I'll be equal to or ahead. Should be interesting...of course we're heading into fall/winter up here so it may be difficult to really track accurate results but I've probably got a month or so to see if it's an apparent improvement.

 

<div class='quotetop'>QUOTE(TomSwift @ Sep 9 2006, 09:55 AM) [snapback]316958[/snapback]</div>

I have no experience with E85 but I am told that you it drops the mileage by as much as 40%. Figure from there.

 

<div class='quotetop'>QUOTE(Dragonfire @ Sep 9 2006, 03:14 PM) [snapback]317063[/snapback]</div>

I believe you about seeing a 76 (union?) truck in your Shell station. But the people that own the brand don't like that. Brand name protection is pretty important to them and they don't like it when people see them comingling because it leads to the belief you have that all the gas is the same.

For the most part, all of the gas is the same. And yes, companies swap stock all the time. The thing that the major brands have is additives that set them apart. The most closely guarded additives are offten added to the trucks right at the terminal when the truck are loaded. I know this to be the case with Chevron's Techron additive - it is not blended with the fuel when it is refined, it is injected at between 180cc and 230cc per 100 gals when the fuel is being loaded on the delivery tanker truck. Chevron may sell fuel to others out of that same truck loading terminal, but wouldn't use their additive. That said, gas at Safeway or Costco MIGHT have come from a Chevron, Shell or 76 terminal (but more likely an independent), but that does not guarantee that it has the refiner's special additive brew (note that all fuel has detergents by law, but automakers have noted that there are differences).

Around here I don't think you would ever see a Chevron truck at a Shell station, or vice versa (BTW Shell in this area is brand, but Equilon actually runs the refineries, terminals and owns the trucks.) Many use third parties for transport. Big one in Northern CA is Beneto out of West Sacramento. They deliver fuel to many different branded and independent stations and I see them packing up loads at numerous terminals. But their additive loads would still be based on where the delivery is going.

 

I've noticed a couple times when I managed to fill my tank (in another car) with more gasoline than the tank would hold according to the owner's manual. One of these times it was at a gas station my wife frequented. We kept fuel consumption records on the gasoline receipts. (When we fill the tank, we'd record the miles driven since the last fillup and the calculated mpg on the receipt showing the gallons used to fill the tank.) After this Getty gas station supposedly put an extra gallon of gas in my tank, I reviewed our mileage records and found that it seemed we generally got worse mileage on tanks ending with a refill at that Getty station. This was regardless of where we filled the tank the previous time (or the gasoline used on the tank ending at this Getty station). I reported this to the Lexington police and Massachusetts weights and measures and haven't gone back. I doubt it made any difference.

I suspect that big deficiencies in calculated mpg may have as much to do with the accuracy of the station's fuel pump meters as with the qualities of the gasoline.

 

Had noticed variation in MPG using two different brands of gas with my 2003 and the same happens with my 2006.
Same route, time, day etc. and I get 4 to 5 MPG higher if I use a Mobil gas station in Montclair than when I use a Shell station in South Pasadena. Any comments on this?

 

<div class='quotetop'>QUOTE(theorist @ Sep 11 2006, 06:14 PM) [snapback]318087[/snapback]</div>

had the same issue with a station (since closed) here as well. reported them to weights and measures, it took 10 months before they inspected the pumps and it was determined the pumps were "inaccurate, but not enough to warrant any further action"...

after that, i track what the pump says, but only really believe what the computer says.

 

My "unofficial" results are in: over the last 3 tanks which I bought from Chevron, I saw no difference in MPG compared to the fuel I've purchased at Costco.

To be fair to Chevron, I plan on running 4 full tanks to see, but now that I'm into my 3rd, no difference.

I did see another post re Chevron's fuel additive (purchase at Costco, no less!) and the mileage improvements gained through it.

What really sucks is that our temperature is starting to drop--this morning I had frost on my windshield--and that really takes an MPG toll!

 

I honestly do believe that there is a difference between brand vs. no brand. I've read many independent comparison studies and the now known "top tier" brands have higher refinement and more than the mininum amount of cleaning detergents (req'd by the gov't).

From my experience (and not just the Prius), using "cheaper" gasoline such as Thrifty, Petro-max, or even Arco I do average a whole 10% or lower mpg. I did also notice that the engine feels more harsh with these brands, but then that might have been mental.

I'm willing to spend those extra 2-5cents and get Chevron or Shell to know that I have gasoline with plenty of cleaning additives. Personally I average about 50-53mpg with either Chevron or Shell. No engine knocking or any strange stuff.

I guess it is like water. Purified, spring, fiji, pellegrino... some people will tell you that there is a difference and others will say otherwise. Chemically we know that they are different, but most people can't even taste the difference. I hope that I was clear enough.