A couple weeks ago, my 4000 mile cross-country trip had me filling up a bit more than usual (as we all know, that's still not that often.. ) I left Albuquerque with Chevron 86 octane gas. I got to outside Amarillo with an average of 51 mpg, and put in more Chevron. Then the mileage plummeted to 44 through Oklahoma... I was determined however to look for another Chevron station (I have an odd brand loyalty; the Techron detergent additive cleans to fuel injectors and intake valves, not a bad deal)... As I drove through Joplin, MO, I realized there were no more Chevrons to be had, so I filled up at Phillips 66 with octane 87. The next segment wasn't bad, until I filled up at a BP/Amoco station. It seemed as though that gas gave me terrible mileage. I then filled up with Shell, which I noticed gave me excellent mileage consistently (about 6 mpg higher than the last tank). When I was in the midwest, there was no Chevron much to my chagrin, so I just used Shell. I thought Shell was good until I had half a tank of Shell and added half a tank of Chevron. The Shell/Chevron mix gave me this seemingly awesome synergistic effect of super high mileage (57 highway), while I still had the cleaning effects of the Techron detergent. When I switched back over to just Chevron, the mileage went down significantly. Yesterday, I just went back to the Shell/Chevron mix, and I am at 54mpg from 42... I know that elevation change and driving habits influence gas mileage, but I seem to definitely notice a trend at certain pumps... Any similar stories anyone?
I might try some different brands. So far I have stuck with Exxon. Interestingly my per tank MPG has been between 46.5 and 48.5. (Most of my trips are under 5 miles.) These were fillups at the Exxon at Germantown and Poplar. I filled up one time at the Exxon at Forest Hill-Irene and Poplar and only got 42.0 on that tank! Also consider that with the long trip, some of your variation may be related to regional EPA mandated differences as much or more than brand.
In many areas, you have no control over what "brand" of gas you are actually buying. Today, most stations purchase their gas from a wholesaler, who then delivers to the station. This is because most stations are francised and are not owned by a brand as they once were. Most will purchase gas from 2 or 3 wholesalers, who get their gas from the refinery of their choice, usually the closest. In other words, your "Shell" gas may not be from a Shell refinery, and your Speedway gas may be from a Shell refinery. As all fuels must be made to a minimum standard, and all are required to have fuel injector and other cleaners in the fuel, you will find that most all gas is the same. The variability usually resides with the station itself. If the storage tanks are dirty, prone to water entry, etc., the quality of the gas will be affected. Age also plays a role. It ends up being very hard to pinpoint mileage or performance decreases to a brand. It's usually the station itself, or the shipment of gas they recently received. The next shipment may be of better or worse quality, and it may come from a different supplier.
While that may be true to a point, most Shell, Cheveron, and ARCO stations have branded trucks delivering their gasoline. Knowing that the first two also have specific additives to their brand in their gasoline, one must know that they - at some point - have some control over the fuel. Where it's refined, however, may be from a single refinery in the end.
I'm impressed with FlyingPrius' recall of the stations, filling points, and attention to such great detail. The few times I've long-hauled across the country, I got gas when and where I needed it and spent very little time deciding on the brand or even remembering the details after the fact.
Many other factors go into milage as well: Temp. Wind conditions, road surface (they chip seal here = take an asphalt surface, spray it with tar and then cover it with rock chips. Very rough, lots of road noise, and I am sure increased rolling resistance), etc. We mostly use a local brand tied to Sinclair Oil but adds 10% Ethanol to further reduce emissions. Current tank running at 54.5 mpg combined highway/city (~75%/25%).
The ethanol will slightly reduce the mpg. I was reading about "alternative fuels" in the latest Consumer Reports just yesterday.
Bruceha, I kinda figured it did but my wife insists. That makes the 54.5 on the current tank even more impressive!!
My choice of gas stations is based entirely on convenience. On a road trip, it depends on the closest one I see to the off-ramp once I decide I have to stop for gas. Except that one time there was a gas station that appeared to be associated with a Walmart, so I went to the next station. Any chain store that pays full-time workers less than the cost of the cheapest apartment...
My understanding is that in the Portland, OR area, most/all gasoline comes in via a single pipeline from refineries in the NW Washington area. Whatever additives (if any) are added (like Techron for Chevron) at the depot when the truck fills up.
That's pretty much true in the Tucson/Phoenix area, too. A couple of high pressure gas line run right along I-10. About a year ago one burst, spraying several houses with gasoline and contaminating the ground. They had to press tanker trucks into service and gas prices in the area jumped accordingly. In fact, I believe that most gasoline in the US is moved around this way. I do know that most of the gas in the US is actually refined elsewhere (I don't think a refinery has opened in the country since the 70s). Thanks, Shawn
I was just wondering about this as AAA offers a 5% discount with Shell. I tend to be "brand" loyal also based on how my car performs. So I hopped on Prius Chat to see if there was any opinions on fuel brands. Granted this is now a 17yr old thread; I did find it interesting. Hope someone *recent* can comment with current thoughts. My car is 2005 with high miles.
