View Full Version : Are all fuel grades created equal

01-21-2011, 05:20 PM
Never really cared about this before, but since I've got a new Bimmer, I'm a bit more aware.

Is 91 Octane at Shell the same quality as 91 Octane at Sams/Costco, BP, Exxon Kroger??

Anyone have some solid advise?

01-21-2011, 06:01 PM
I just finished watching slide show from Shell

Slide Show (http://www.nealswheals.com/NealsVisitors//PDFs/Gasoline_Media_Presentation_FINAL.pdf) <---Click
Base fuel may be similar between two or more brands, but the additivemay be different for each brand
What are Gasoline Additives?
•EPA minimumdetergency standard is known as the Lowest Additive Concentration (LAC) which is designed to help control exhaust emissions
•Several companies (e.g. Shell) use additives that feature higher levels of cleaning agents and offer additional benefits
•But a significant amount of gasoline sold in the U.S. is at LAC levels only

•Many discount brands continue to sell fuels with minimum detergency to meet the government standards (e.g. low-detergency fuels), which ultimately may affect the performance of a car’s engine
•Five of the largest auto makers are concerned about fuel quality and have set a higher standard…… General Motors, BMW, Honda, Toyota and Volkswagen

01-21-2011, 06:56 PM
Thanks, that was very informative. How many folks use Shell? Plus or v-power?

01-21-2011, 07:22 PM
Thanks, that was very informative. How many folks use Shell? Plus or v-power?

I've used all grades of Shell in the assorted vehicles I've owned. If the manufacturer recommends premium unleaded, I just go for the V-Power.

But regardless of the recommended grade, all my vehicles all seem to run pretty well on Shell -- as well as Chevron, Texaco (which I think Chevron owns at this point), and Sunoco...

01-22-2011, 05:28 PM
I was watching a show on the History Channel that said the same basic thing, that all gas is the same except for the additives that each brand puts it in. Another fun little fact that I found was that there is this pipeline that I believe runs from Texas to the Northeast, and gas companies are able to deposit say 10,000 gallons in Texas and then withdraw the same amount in Boston same day, for a small fee per gallon, illustrating that all gas is the same since they are allowed to take it out at any point in the line and then add additives and deliver it to their local stations.

Interesting factoid of the day.

01-23-2011, 03:51 AM
The answer to your question. Mobil/Exxon were added since the last time I looked to the list


And the test... Odd that the standard used an old Ford 2.3 Liter engine.

01-23-2011, 06:04 PM
It's the additives that make the difference. The petrol and diesel comes from the same refinery, generally speaking.

01-23-2011, 08:31 PM
funny, you could say essentially the same thing about Vodka. Mass produced by a handful of producers then distributed and marketed under different brands for different prices. In the end, all essentially the same.

01-23-2011, 10:19 PM
I try to use Shell in my car, though there are few shell stations around here. While the M3 hasn't been too picky about the gas, it seems to run just a little bit better w/ their V-Power. If Sunoco still offered their 94 octane gas, I'd probably use them.

01-24-2011, 07:48 AM
#2 and #5 are closest to the truth. There are about 140 petroleum refineries in the U.S., of which about 100 have a processing capacity of at least 50,000 barrels per day (the largest is 560,000 barrels per day). Almost all refineries that produce gasoline also produce diesel, since the two fuels come from different cuts of the crude oil, although a refinery can vary the ratio of gasoline to diesel production to some degree depending on processing equipment and types of crudes being processed.

Basestock gasoline (and diesel) are fungible commodities (similar to corn, soybeans, wheat, etc.), which have to meet a complex set of minimum properties (octane rating, cetane rating, vapor pressure, sulfur content, etc.). This allows the fuels to be freely interchanged among the many wholesalers and retailers. The gasoline you buy at the local Shell station MAY have come from a Shell refinery, but more likely it came from an ExxonMobil or Chevron refinery (or some other refinery). If you think about it a minute, it could be no other way. If each oil company had to physically supply its retail gasoline stations from it own refineries, the logistics and transportation costs would greatly increase the retail price of gasoline (and would limit your choice of brands in your specific area).

Although there are lots of pipelines running across the U.S., the two major ones referred to above are the Colonial and the Plantation pipelines, which transport fuels from the Texas Gulf Coast and Louisiana (where the refineries are) to the New England and Atlantic states (where the people and cars are). An oil company can put its own 10,000 gallons of regular unleaded basestock gasoline in the pipeline, and take out 10,000 gallons of regular unleaded basestock gasoline (produced by some other company) at the other end.

Each refinery produces basestock fuels that just meet the minimum requirements, because there is no premium paid for producing better than minimum fuel (e.g., if the minimum spec for regular is 87 octane, the company does not get paid more for producing regular that is 87.5 octane). What makes Exxon gasoline Exxon, and Shell gasoline Shell, are the types and amounts of additives they put into the basestock gasoline, which do differ from brand to brand, and to some extent how each company handles, transports, and stores its fuels once they take possession of the basestock. As you can see from the TopTier list, some brands of gasoline are "better" than other brands.

My recommendation is that for your BMW you stay with one of the major oil company branded stations, AND that you get your fuels from a relatively new station (with its relatively new storage tanks). This will help ensure (but not guarantee) that you get the best additive packages and that your fuel is not contaminated.

01-24-2011, 01:34 PM
Here in New Jersey we have a major refinery operated by Conoco-Philips. It's the one we pass as we travel through the state using the NJ Turnpike. My son works there and he confirms what others have so aptly written. It's all the same stuff when it leaves the refinery. He tells me that tanker trucks of all name brands come in to fill up. Exxon owns excusive use to a couple of bays but only to expidite the movement of their tankers. The fuel they get, be it gas/diesel is all the same. The other trucks just have to wait their turn to fill up.

I'm still not clear on if any "brand" is any better than another. My Beemer doesn't seem to know the difference. Or maybe it's just that I can't tell the difference. Either may be the case. For my diesel truck I just try to stay with a retailer that I know that has a high enough volume so the fuel doesn't sit in the ground too long. Have had no problems yet.

01-24-2011, 03:38 PM
For what it's worth, the only times I have ever experienced car problems that were directly traceable to bad gas, it was from "Top Tier" stations. The first time was years ago (before "Top Tier" was even an idea in a marketing guy's head); my parent's car dieing and then running extremely poorly starting about 200 yards after leaving a Shell station. The problem was improved when the the luckily not full gas tank was topped off with gas from a nearby Arco, and completely resolved when that tank was run almost empty and was filled up to the top with gas from another Arco station.

The second problem was from a Chevron station. A work truck I drove got filled up there because that's where they had a gas card. About every 10,000 miles it needed its fuel filter replaced because it was clogged with sludge. Meanwhile my BMW gets filled almost exclusively with Costco gas (which is sourced from 76, Shell, etc; whoever happens to be cheapest at the time) and when I finally changed my filter at 135,000 miles, the gas that came out of it was still clean and clear.

"Top Tier" would carry more weight with me if there were any reports of a retailer not meeting that standard. "Top Tier" seems to be more about marketing than anything else. Make sure your gas meets standards that are probably no stricter than the ones all gas already has to meet, pay to join the club, and advertise yourself as being "Top Tier". It's a great way to attract customers that like being told what they're using is special without having to prove it.

Gas quality has much more to do with the individual stations than it does with the brand of gas you go with. An independent Top Tier station might be owned by a cheapskate that only changes the filters when they're clogged enough to only let gas trickle out of the pumps. Meanwhile the "Bob's gas-o-rama" across the street might be owned by a guy that makes sure to change them before they need it and performs regular maintenance on all equipment.

01-24-2011, 05:49 PM
In the mid '80's I recall having a problem with "bad" gas that took a long time to find the cause of. I'm a retired police officer. We fueled our patrol cars at a privately owned in ground tank. Many in house vehicles got gas there every day but we were the only ones using the pumps 24hrs./ day. The cars were Ford crown victoria police cars and these were the last days of carburated engines and going into newer cars with fuel injection. It seemed that on nights with heavy rain when we filled up our cars they would stall right outside of the pump area and need to be towed in to the shop. The next day they would drain the tank and find a lot of water. We had our in ground tanks checked and they tested OK. After numerous happenings it was finally determined that since we were filling up at all hours including during heavy rains we were picking up quantities of water. The tanks were old and had major water infilitration. After some time passes and the water/gas had time to separate other users were not having any problems. This took a long time to be discovered and shortly after they removed the tanks and installed a new above ground fueling system. Older cars in our fleet had carburators and would run poorly for a little while but never were disabled. Newer cars had fuel injection and were immediatly disabled requiring a tow.

The point here is that as cars have become higher tech they are more sensitive to contaminents in the fuel. Clean fuel, good filtration and good water separation is essential to our high tech engines. :thumbup:

01-25-2011, 10:28 AM
"Top Tier" would carry more weight with me if there were any reports of a retailer not meeting that standard. "Top Tier" seems to be more about marketing than anything else.

That's my take on this as well. Marketing. I've been filling up at Costco for years and never had any problems.

01-25-2011, 12:42 PM
So what are these additives that the oil companies add? What do they do?

Years ago Shell used to advertise "Shell With TCP".

We called it Tomcat Piss! :rofl::rofl:

01-27-2011, 06:48 PM
So far I've put kroger and shell in my tank. Both the highest octane available, no noticeable difference yet.