MrMischief

I’m asking because I usually get 26 gallons of any grade gas free every month and I could use some of it in the MB 560. It’s from the grocery store gas station, their tanker trucks don’t provide any hint where it comes from.

superswiss

It is highly recommended that you use TOP TIER fuel as it contains the necessary detergents to keep the high pressure fuel injectors clean and reduces the likelihood of them clogging up and resulting in an expensive repair. MB specifically recommends TOP TIER fuel. It doesn't matter where your grocery stores gets the fuel from. Hydrocarbons are hydrocarbons, but the additives matter.

https://www.toptiergas.com/fuel-stations/

dmatre

Watch this before making your decision, understanding that your car is turbocharged and direct injection.

SW20S

I wouldn't do it in my car, no. If you do use that fuel, I would run a fuel additive in it from time to time.

tx170754

It may sound crazy but I'm only using 93.

carlosinseattle

https://mbworld.org/forums/s-class-w...100-wrong.html

Read that thrread and the report attached, and you'll know more than you'll ever want to know about proper fuels. I'm heading out to buy some PEA right now.

Barry Hanna

I use Red Line fuel system cleaner as a supplement to Top Tier gas. I use a 1/2 bottle every fill up. I believe even the best fuel requires some additional additive. If your driving is 50% or more highway then you might reduce the additive to 1/2 a bottle every other fill up. It’s also the practice of some fanatics, like me, to change fuel suppliers every fourth tank or so to cover all the additive formulas. The latter was some fatherly advice from a man who spent his entire life in the oil business. Anyway, to me this is all cheap insurance and I’ve never had an engine failure and some have gone well north of 100k.

will_atl

I currently work for a convenience retail chain (petrol/gas stations), we are not listed in the Top Tier list, but we do sell to some who are 🤷🏻‍♂️ I am now loyal to the company that I work for, but before working here, I used to go to my local Kroger to fill up, (which is what my wife still does). We’ve never had an engine issue in any of my turbo charged Mercedes, 7 of them including one AMG. I’m not saying gas related issues, we just haven’t had to do any engine work done apart from service and maintenance (unless you count one pulley that I replaced on my CLS). Just one man’s opinion, but I try to buy from stores that are high traffic and I don’t buy into the Top Tier marketing.

MercFan4Life

I'm not putting Wal-Mart/Sams Club/dirty China gas in my Merc. I will use Sheetz, Exxon, Shell, or Marathon only. I could be wrong but I sleep better at night this way.

W205C43PFL

I will too choose Shell, by the way, here are two good thread to read:
https://mbworld.org/forums/gle-class...-fuel-gle.html
https://mbworld.org/forums/s-class-w...100-wrong.html

carlosinseattle

Did you read the report that was attached in the other thread? If so, you'd realize it's not about marketing, not at all. Marketing is designed to bring awareness, and practically nobody knows about top tier fuels, so by definition it's NOT marketing. It was developed by the auto makers to try to increase the longevity of their cars. Gasoline formulations were a hindrence to performance and longevity, so Auto Manufacturers specified what was needed in order to properly maintain the health of their engines. Then the gas companies said prove it, and they did, then they agreed that a number of additives were neccesary an that's where top tier fuels came from. It was science, and two industries working together, but not marketing. Additionally; it's been proven many times how and why these additives work. We are inundated with all kinds of "hype" everyday from companies, but that's not the case in this situation.

Having said that, nobody has to buy top tier fuels. You can trade in yor car every few years, in that case this means nothing. Or you can buy additives over the counter like @Barry Hanna . Luckily, I've done that for the4 last 20 years, just like him. But after reading the report I've decided to step up the frequency of using additives, and "primarily" use top tier fuels. You do a lot of highway driving and change cars frequently, so this isn't as relevant to you as others.

AMG__POWER

I’ve always wondered about this bc here in CA our “top tier” is 91 which is garbage lol but I only use Chevron or shell which is the highest quality gas they say

MrMischief

I’m sure none of the used car dealers spend money on Top Tier fuels. Carmax has their own tank and I Seriously doubt that place can do anything above board! I bought my first tank of fuel yesterday and it was Exxon’s highest octane fuel at a $1.00 more per gallon. The majority of fueling stations out here are the cheaper places - the largest is a convenience store called WaWa, Turkey Hill, Vevo,Giant and Wiese . The Exxon, Mobile are around but not so much. Shell and Sunoco has spread out 15 miles apart and by coincidence the nearest Sunoco is 15 miles from me. Texacos are few and far between. Citco even less of them. I always thought of Sheetz as a cheap gas like those I mentioned above. The guys on the Corvette Forum are fanatics about their cars and some would only put 104 Octane from Sunoco and it can be 30 miles out of the way to get to the one Sunoco that sells it.

MrMischief

And that can change by the rumors. I think I’ll run 93 or better and just have injector cleaner I can add at fill ups.

superswiss

Just for clarification, TOP TIER has nothing to do with octane, and octane says nothing about fuel quality. Octane simply measures the resistance of the fuel to ignite under pressure. Higher octane is not automatically better unless the engine mapping can take advantage of it. US spec engines are mapped for 91 AKI. The ignition timing is fully advanced at 91 octane, so filling it with 93 provides no gains unless you get an aftermarket tune with a 93 octane map. Those tunes usually don't get much more out of 91 and require at least 93 to make the advertised figures. The octane rating these days is essentially achieved by mixing in ethanol. Ethanol is an octane booster and oxidizer, and it produces more power than gasoline by itself, because ethanol burns much quicker than gasoline. 1 gallon of ethanol has less energy, though, so you burn more, but get more power out of it compared pure gasoline. This is why Koenigsegg and other very high performance engines only make their rated power on E85. They make less power on pump gasoline.

tx170754

Interesting, so for a novice like me, what is the difference between 91 octane with Ethanol and 93 octane without Ethanol ! Obviously the price is different !

superswiss

The 93 w/o Ethanol will yield a slightly better mpg.

tx170754

Well, thank you very much, coming from Europe I've always looking for the higher octane.

superswiss

I forgot to add, the engine will make slightly less peak power w/o Ethanol. Europe and USA don't use the same octane system. Europe uses RON, whereas the USA uses AKI. 91 AKI (US) is roughly equivalent to 95 RON (Europe). 93 US is roughly equivalent to 98 RON, but again, the engine maps account for the difference. I did European delivery with my AMG, and MB changed the engine map for while my car was in Europe and then changed it to the 91 map once the car arrived in the US. Obsessing about the octane is pretty pointless with the stock maps. The car manufacturers already factored in the prevailing octane of the most commonly available premium fuel. In the US that's 91 AKI and in Europe it's 98 RON.

Edit: The US system is actually somewhat more accurate as AKI is the average between MON and RON. Europe only measures RON, but the US also measures MON and then takes the average.

https://www.eia.gov/energyexplained/...e-in-depth.php

SW20S

There is no such thing as "china gas" lol. Its the same gas thats at a Sheetz, etc. Sheetz is not Top Tier by the way. Exxon, Shell, Marathon, and other big brands have good additive packages that keep the engine clean top tier rated or not. Something like Sheetz and no name stations don't, even though its the same fuel.

tx170754

That is really interesting, at least for me, thanks again !

superswiss

And I just edited my post to add that he US system is actually somewhat more accurate as it measures MON and RON and then takes the average. MON is the octane of the fuel at higher temperatures and engine speeds. Europe doesn't measure MON, only RON.

https://www.eia.gov/energyexplained/...e-in-depth.php

tx170754

Yes I saw that, thank you !

superswiss

If you wanna make it even more interesting you also have to factor in elevation. Here in California I'm at sea level. While turbocharged engines can compensate for elevation to some extent, the higher up you are, the less power you get out of your engine. So running 93 up in Denver, although I think Colorado also only has 91, won't make the car faster compared to running it at sea level on 91. Higher octane at higher elevations is actually counterproductive. Especially the turbo lag gets increasingly worse the higher the elevation. I once took an Audi S3 with its turbocharged 4-cylinder engine up to 9000 feet. It was barely drivable at that elevation. The turbo lag was horrible.

tx170754

That is also interesting, so, we are eventually moving to Santa Fe, our new house is at 7500 feet, should I sell my S560 ? All the other three cars we have are not turbo !