aznmode

I was just reading the same thing on Yahoo news. I've always used shell or Chevron and tend to stay away from Arco and 76. Although sometimes you really have no choice. I remember using Arco once and my throttle wasn't as stiff. I really don't know whether thats a good thing or not but I liked it. Gas mileage is really hard to guage. But knowing it's only the additives that makes a difference, I may just used STP additives from time to time instead of going with the higher brand gas.

zoomie

Definitely.
I totally agree with everything you said.
I only mention the Rav4 b/c with such a weak engine, it seemed like it was easier to tell when different brands made a difference. It was in fact designed for 87 octane.

Mu9enx

92? i think we only get 91 the most down here and in sac. i don't like Arco, or any off brand gas for that matter. Valero is just the same as Arco to me, cheap gas for cheaper cars. i use Shell, Chevron, 76 or Mobil1 when available. i pump at the 76 on mission in san gabriel all the time, cheap and great!

on a note though, is Mobil1 considered one of the top? i always thought it was, but a lot of my friends disagree. any ideas?

alpinweiss

Whatever gasoline you choose for your Mercedes, make sure it meets the top tier standard.

www.toptiergas.com

Konka

It doesn't really matter because a sign that says Shell doesn't mean that the product is Shell. Gas stations, unless owned by Shell or whoever, just buy the rights to use the insignia of a company but don't necessarily carry, or have to carry for that matter, their product. That's why you see Shell's with high prices and then others, usually across the street from generic no name stations, with low prices. The best way to make sure your getting Shell or whatever and not crap is to go to stand alone stations, ones that are the only in the area because others are usually the same franchiser using two stations to sell the same thing, one cheap for the people looking to save a penny and one a little more expensive to trick people into buying a superior product.

KIRA

i have no idea really...

when you push 91 octane button but how would you know??

you might be FUELING IT WITH 87 GAS!!

and how would u know if the gas company heat their gas up to make it look increase or not?

Buellwinkle

It's funny to see what people think about their fuel. Basically it all comes from dinosaurs that died so we can drive MB's without a care. I worked for 76 for a few years, fun place to work. Coincidently, I worked in their pricing dept so I know who/what/where fuel is sold because it's priced for all customers, retail and wholesale. So this is the way it works, oil companies have storage tanks call terminals. These terminals serve local areas, so for example there's a terminal in Los Angeles for Chevron, 76, Mobile etc. The fuels are kept in seperate tanks based on octane, oxygenation levels, lead levels, jet fuel, kerosene, avgas, heating oil, etc and is usually stored as what is called branded fuel. Branded fuel is fuel that has that companies secret sauce, it's additives, some mandated, some not. While there are adatives that are mandated, the actual formulas are different across different companies. They also may maintain unbranded fuel, this is fuel that has no additives other than oxygenates required by law and is used to trade with other terminals. Branded fuels are delivered to wholesale (fleets) and retail stations for that brand, so 76 branded fuel goes to 76 stations, never to a Shell station for example. Unbranded fuels are sold from one oil company to another. For example, in Hawaii, 76 didn't have a terminal, so they bought unbranded Chevron fuel and then additives where added by 76 in the oil tanker to make it 76 branded fuel before delivering it to a 76 station. In return, Chevron buys fuel from 76 in other markets where it doesn't have a terminal and 76 had a good network in Alaska for example where maybe Chevron got fuel from them, don't remember where but I do know they exchanged fuel, usually at what is called the pipeline price. The exchanges also happen when one terminal is short, for example, Chevron is short on jet fuel, 76 is short on home heating oil, so they buy from each other. Oil companies have traders that do this all day long, it's not rare by anymeans. There are companies that provide pricing information and you may have heard of them on the news, Lundberg which caters mostly to retail pricing (what you pay at the pump) and OPIS which caters mostly to wholesale pricing.

So what are you getting, at minimum you are getting fuel that meets the local standards for oxygenation, if not they can get fined heavily so in CA, the oxygenations requirements are seasonal. Some companies like Chevron advertise additives like Techroline, this goes above and beyond mandated additives and that's their trademark. When you go to a Costco for example or a small independant station, they usually have their own fleets and get dailing pricing from different vendors, so they may get a pricing sheet from 76, Chevron, Tessoro, etc. (I know I put these out). They look at the pricing and early in the morning, they call in their orders and later in the day send their trucks down and pickup the fuel. What fuel depends on who's low bid at that terminal, so for example, if LA terminal for Chevron is 1 cent cheaper than the Tessoro price at Orange County, they may pay the higher price for Tessoro over Chevron for the convenience so you never know what you will get. Also, some bigger outfits get price guaranttees for a period of time so it's not always the lowest price but in general it is. But keep in mind, they are buying unbranded fuel so does it really matter where they get it from? If you go to Chevron station, the fuel may or may not have come from a Chevron terminal but it really doesn't matter because it has Chevron's secret sauce.

I personally like Chevron, and in cases where i've had pinging issues on older cars, motorcycles and such, Chevrons formulations seem to work better for me. In the MB, doesn't matter wether I get fuel from Costco or Chevron. So for my Buell which has been known to ping as much as any Harley, I only use Chevron.

Mu9enx

to sum it up, does it mean that gas is gas, but brand names have their own secret formula? i couldn't fully understand your post, so is konka correct on his analysis?

blackcls63

same here, great post, but is for eg, valero good enough for our mb's ?

Buellwinkle

Yes, gasoline is gasoline (they don't like the word gas at oil companies, means something different than gasoline) but different oil companies have different formulations to meet federal mandates as well as additional additives, for example Chevron's Techroline. BUT, some cars/bikes/lawnmowers are more sensitive to different formulations than others. Some cars run better on one forumlation and another car may run better with a different one, takes some experimentation. My experience on the C230 is that it can handle anything, don't worry about it, Vallero, Costco, Tessoro, Thrifty, Arco and Shell will be fine.

On cars/bikes/lawnmowers that are sensitive to formulations, I've had poor experience with Shell and Arco so I tend to stay away from them even with my Benz mostly out of habit than practicality. I've been filling up at Costco for the past few months for 2 reasons, 1) it's cheap, 2) it's the closest station to my house and I've haven't noticed any difference at all in fuel mileage or performance.

nlpamg

great post Buell! I got a lot out of that.

I agree with you with regards to the gas on the C230. I don't feel the slightest difference when I put in Costco, Shell or Chevron in the car (Costco is the "cheapest" gas I'll put in it). Although, last time I was at Costco, they had signs saying that they also put additives in their gas to "keep your engine clean." I don't know about their statements, but hey, if it's true then it's not a bad deal.

With the M3 on the other hand, I can absolutely tell between Shell and Chevron. The car only gets Shell, Chevron or 76 and you can tell a noticeable difference between Shell or Chevron (I don't put 76 often enough to really tell). The car seems to run smoother on Chevron and have a much smoother idle.

Ryanr317

We get 93 down here. I usually go the BP.

Mu9enx

i wonder how much more hp my car would make with 93..

is california the only state with less than great gas octanes?

Ryanr317

Probably somewhere around .1hp.

tbenz

thats very well said,, the one thing i have to add is if you use cheaper fuel without some of the secret sauce you will start developing carbon build up which will give you more problems in the long run, regardless of the octane rating

calimax

Nope! we get 91 here in AZ, although I tend to run 101 or higher at the race pump here at some fueling stations, at least a tank full a month. Purrrrrs like a kitten, but at $5 a gallon!

mtnman82

My twisted logic: I mostly run VP racing fuel, 91 octane, from the pump. I like to support the local station because they also have 95 and 100 octane at the pump (bucks up $$$$$), which I can take advantage of in my other boosted vehicle. You only need to run enough octane so as not to retard timing or to prevent detonation, so running more than 91 octane in a vehicle tuned for 91 octane IMHO is just burning those extra dollars. I will also run a tank of Chevron through every now and again, because I always hear good things about Techroline (sp?) working to keep the injectors clean. If I'm out of town, I have no problem with Shell, 76, etc. if it's convenient. I've learned the hard way about some of the smaller indy stations and getting gunk in my tank/filter ... back in the day when every buck counted.

Anyone notice how the price of the 'race' fuels (i.e. above 93 octane) varies very little, if at all, compared to the 'regular' grades? What's up with that? Maybe Buell can shed some light?

pookie

shell 93. only 2 cent/g difference and peace of mind.

Buellwinkle

For fun I actually dynoed on 100 unleaded from 76 Racing. I ran the tank of 91 octane as close to empty as I felt comfortable, fillled up on 100 octane, ran until the car had about 1/4 tank left to make sure that if there was any adaptation it would have taken place by then. I had a pullied C-Coupe so if there was any advantages to more octane it would be more exaggerated in this case. The dyno showed the same exact HP/Torque numbers between 91 and 100 octane, no difference averaged over 3 pulls. In my mind I didn't expect any changes as the car was not pinging and if I took an older C230 from 1999 or an older SLK230 with a pully kit it would likely have showed an improvement because those cars are more likely to ping with a pulley kit.

Just to be clear, octane ratings measure a gasoline's ability to resist engine knock, a rattling or pinging sound that results from premature ignition of the fuel-air mixture. Higher octane does not mean more power, more BTU's per gallong, more energy, it's all the same. By now most states consider 91 octane as premium. This was a cost saving move to protect consumers. For example, the percentage difference for premium used to be considerably higher in CA when it was 92 octane (don't think it was ever 93 here). I can tell that when I travel to Florida where they have 93 octane, the percentage difference is higher so you do pay more of a premium for premium there. Of course it's moot because gasoline costs a lot more in So Cal than in Florida, their 93 octane is priced lower than our regular.

s1mple

First of all, gas stations have to pass inspection like at least twice a year, random checks happen. A guy from the state would come down make sure every cent and drop is given to the customer, the grades are properly set, water levels in the tank etc.
On the gas heating situation, theres no possible way you can "heat up" the gas, the gas is inside a tank that is buried a good 5 feet under the ground.
I have also experimented with the myth that says "you get more of your moneys worth if you fill up on gas in the morning because it is colder."
truth is, thats is not true. as i said earlier the gas tank is buried under ground and there was only approximately 2-3 degree temperature changes in the gas. My parents own a gas station and i work there is how i know. in the back we have a machine that prints out all this information when you want. it tells you how much gas you have in the tank, temperature, how much more gas you can add till its full etc.
I live on the mississippi gulf coast, and 93 octane is what we get down here as "premium." Down the road from my store, there is a Chevron refinery plant, and that is where all the gas comes from. as others have said the only difference is the additives that are present in the fuel. and from what i know and have been told by those chevron workers, BP gas should be the best. They even said that BP's regular is almost comparable to Chevron's Techtron. Just about all gas comes from chevron plants because they have the most gas reserves.

BlackLiquorish8

theres 2 shell stations right in my town so i use shell there are cheaper places but i dk i feel like shell's gas is the best


is it true that shell's gas is cleaner than other brands tho??

Mu9enx

bp as in british petroleum? as in arco? i refuse to believe that

Buellwinkle

When we priced fuel we had some customers that wanted to be charged gross gallons which is the actual volumetric quantity and some wanted to be charged net gallons which is temperature adjusted to 60 degrees F. So there is a difference but on a tanker the cost difference was so small, maybe a few cents per tanker. Net measurement was mostly for larger customers that bought larger quantities of fuel, like airlines that wanted things priced to one thousands of a cent which would mean almost nothing on a 8,000 tanker but when you buy 100,000 gallons of jet fuel and do it across the entire country, and save a pennies on a smaller bags of peanuts, it adds up. So it could be possible that if you bought your fuel in the morning for your entire life, you may have a lifetime savings of as much as a $1. If you have to dream, dream big, hahaha.

calimax

Agree with you 100% And here in AZ, on a hot summer day, you really can hear and feel the difference with the higher octane. It also allows the ability to adjust for higher levels of boost in other turbo applications, that will need it.
BTW I'll let the car nearly stall on fumes at the pump, to not alter the octane rating at all.

FrankW

octane rating can mean HP if your car is tuned for it. For a car that's not tuned for 100 with the ignition timing etc using the 100 is useless. California 91 is more like 89 in East Coast due to the regulation and additives.

For example, my friend's B5 S4 with the GIAC that can be setup to remember 3 different tunes has his car setup for 100, 93, and 91 CA gas. He moved to CA from NJ, so he of course had some dyno done at both places. The gas really made a difference in his car's power output.

anyway, back to topic. I get the most mileage out of using mobil1 91s.