Regular Gas
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From: Long Island, NY
'04 Porsche 996TT X-50, '95 M3 Built & Blown
There is an option in Star Diagnostics to program the ECU with "Less than required fuel grade" option. This allows you to run 87. But why would you? How much money are you ACTUALLY saving in the end? 
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From: San Jose area
'19 E63S sedan
The Factory Approved Service Products that comes with the car states:
To maintain engine durability and performance, use only premium unleaded gasoline. If premium unleaded is not available and low octane gasoline is used, follow these precautions:
• Partially fill the fuel tank with unleaded regular gasoline and fill up with premium unleaded as soon as possible.
• Avoid full throttle driving and abrupt acceleration.
• Do not exceed engine speeds of 2000 rpm if the vehicle has a light load - such as two occupants and no luggage.
• Do not exceed 2/3 of maximum accelerator pedal position if the vehicle is fully loaded or operating in mountainous terrain.
The manual also states:• Partially fill the fuel tank with unleaded regular gasoline and fill up with premium unleaded as soon as possible.
• Avoid full throttle driving and abrupt acceleration.
• Do not exceed engine speeds of 2000 rpm if the vehicle has a light load - such as two occupants and no luggage.
• Do not exceed 2/3 of maximum accelerator pedal position if the vehicle is fully loaded or operating in mountainous terrain.
Damage or malfunction resulting from poor fuel quality or from blending additional fuel additives other than those tested and approved by us for use on Mercedes-Benz vehicles are not covered by the Mercedes-Benz Limited Warranty or by any pre-owned or Extended Limited warranties.
The engine's knock detector should prevent damage from lower octane if you follow the instructions and don't load the engine very heavily, but MB doesn't make this stuff up to sell premium gas.
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04 S430 (sold),05 X5 4.4i, 02 325i, 87 560SL, 85 Alfa Romeo
The Factory Approved Service Products that comes with the car states:
To maintain engine durability and performance, use only premium unleaded gasoline. If premium unleaded is not available and low octane gasoline is used, follow these precautions:
• Partially fill the fuel tank with unleaded regular gasoline and fill up with premium unleaded as soon as possible.
• Avoid full throttle driving and abrupt acceleration.
• Do not exceed engine speeds of 2000 rpm if the vehicle has a light load - such as two occupants and no luggage.
• Do not exceed 2/3 of maximum accelerator pedal position if the vehicle is fully loaded or operating in mountainous terrain.
The manual also states:• Partially fill the fuel tank with unleaded regular gasoline and fill up with premium unleaded as soon as possible.
• Avoid full throttle driving and abrupt acceleration.
• Do not exceed engine speeds of 2000 rpm if the vehicle has a light load - such as two occupants and no luggage.
• Do not exceed 2/3 of maximum accelerator pedal position if the vehicle is fully loaded or operating in mountainous terrain.
Damage or malfunction resulting from poor fuel quality or from blending additional fuel additives other than those tested and approved by us for use on Mercedes-Benz vehicles are not covered by the Mercedes-Benz Limited Warranty or by any pre-owned or Extended Limited warranties.
The engine's knock detector should prevent damage from lower octane if you follow the instructions and don't load the engine very heavily, but MB doesn't make this stuff up to sell premium gas.Clarify this. THe AMG literature correct?
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All literature...this is what is says in my 126 manuals.
Regarding the voided warranty, I heard about it from someone from DAG, and confirmed by my SA.
A specific story he told me about a customer who had apparently run his S430 or 500 on regular from day one, and the carbon buildup caused some sort of collision between the piston and head, and the engine needed to be replaced. It would have been under warranty, but there were plenty of predetonation codes stored in the computer to indicate it was an octane issue, and a simple fuel test confirmed it.
Regarding the voided warranty, I heard about it from someone from DAG, and confirmed by my SA.
A specific story he told me about a customer who had apparently run his S430 or 500 on regular from day one, and the carbon buildup caused some sort of collision between the piston and head, and the engine needed to be replaced. It would have been under warranty, but there were plenty of predetonation codes stored in the computer to indicate it was an octane issue, and a simple fuel test confirmed it.
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Here's the truth about fuel....
Anybody who thinks their car won run on Non-premuim fuel is mistaken. The sam goes for those who claim "Potential engine damage" PLEASE!! IF you look at your manuals the actual "reccommend" Octane can't even be purchased in the US. so that's a joke..
And what about Venezuela, mexico, Germany, and many other countries I've visited recently and notice they too have quite a variation of fuel flavers to choose from.. IT's the same car no?
On the other hand,, and this is going to sound really hypocritical so read carefully, IF your car states that you NEED to use premium gas as Mercedes cars do.. (noting that some maufactures such as nissan only "recommend" the use uf Premium) and you decide to use Lower Octane gas and think you are doing the right thing, well. I have to say that you are mistaken also but for a different reason..
First for clarification the term "Regular Gas" is outdated as it refers to "Leaded" gas that hasn't been sold in the US for the pass two decades..
so you basically have Unleaded that comes in two flavors and then you have Premium.
The difference between the three obviously is the amount of octane that each contains based on a standard calculation with the ladder representing the highest amount.
SO. the issue with MB cars with Low Octane fuel as Newton stated is the presence of detonation from prematurely burned gas. this of course causes the "knockin" sound and as we all know these cars are equipped with a zillion devices that begin to work overtime to try to reduce this effect resulting in diminished performance of the vehicle. Which I might add results in decreased fuel economy which underminds the whole point of trying to save a few pennies per gallon in the first place.
IMO. if someone filled their tank with 87 Octane as the O/P did and it ran as described as a result of the fuel, I would say that it was the crappy fuel in the first place not the level of Octane. In any case you just drive the thing the 250 to 300 miles maximum you're gonna get till it gets near empty and put in higher Octane. Problem solved.. don;t do it again.... BUt siphoning and thinking OMG my engine is going to need replaceing is just dramatic and frankly a waste of time.
BTW. I'd like to see 1 case of a warranty being void as a result of using commercially sold UNLEADED fuel. I'll bet there isn't one. NOt to say that i condone this, but the point is there is no catagory of "Substandard and "Okay to use fule" otherwise the oil companie would be held liable and who would go to a pump and select "substandard" and fill their car. There is nothing wrong woith any of the three types of unleaded fuel you an get here whether its 87, 89, or 91 ist' all "good" fuel when applied in the right application.
NO one could really be able to have enought evidence of "substandard" fuel causeng a warranty to be voided.. and even if thats the case what part of the warranty would we be talking about? a new car with a blown" rod knocking" What?
I think that's just nonsense and not even worthy of mental entertainment.
As you can see from reading posts here some guy uses low Octane in a lease vehicle.. turns it in, with low miles it will moe than likely be sold as CPO and then what? please with this fuel stuff.
Moral:
Don't be cheap. do what your sticker in your fuel door say's.
Anybody who thinks their car won run on Non-premuim fuel is mistaken. The sam goes for those who claim "Potential engine damage" PLEASE!! IF you look at your manuals the actual "reccommend" Octane can't even be purchased in the US. so that's a joke..
And what about Venezuela, mexico, Germany, and many other countries I've visited recently and notice they too have quite a variation of fuel flavers to choose from.. IT's the same car no?
On the other hand,, and this is going to sound really hypocritical so read carefully, IF your car states that you NEED to use premium gas as Mercedes cars do.. (noting that some maufactures such as nissan only "recommend" the use uf Premium) and you decide to use Lower Octane gas and think you are doing the right thing, well. I have to say that you are mistaken also but for a different reason..
First for clarification the term "Regular Gas" is outdated as it refers to "Leaded" gas that hasn't been sold in the US for the pass two decades..
so you basically have Unleaded that comes in two flavors and then you have Premium.
The difference between the three obviously is the amount of octane that each contains based on a standard calculation with the ladder representing the highest amount.
SO. the issue with MB cars with Low Octane fuel as Newton stated is the presence of detonation from prematurely burned gas. this of course causes the "knockin" sound and as we all know these cars are equipped with a zillion devices that begin to work overtime to try to reduce this effect resulting in diminished performance of the vehicle. Which I might add results in decreased fuel economy which underminds the whole point of trying to save a few pennies per gallon in the first place.
IMO. if someone filled their tank with 87 Octane as the O/P did and it ran as described as a result of the fuel, I would say that it was the crappy fuel in the first place not the level of Octane. In any case you just drive the thing the 250 to 300 miles maximum you're gonna get till it gets near empty and put in higher Octane. Problem solved.. don;t do it again.... BUt siphoning and thinking OMG my engine is going to need replaceing is just dramatic and frankly a waste of time.
BTW. I'd like to see 1 case of a warranty being void as a result of using commercially sold UNLEADED fuel. I'll bet there isn't one. NOt to say that i condone this, but the point is there is no catagory of "Substandard and "Okay to use fule" otherwise the oil companie would be held liable and who would go to a pump and select "substandard" and fill their car. There is nothing wrong woith any of the three types of unleaded fuel you an get here whether its 87, 89, or 91 ist' all "good" fuel when applied in the right application.
NO one could really be able to have enought evidence of "substandard" fuel causeng a warranty to be voided.. and even if thats the case what part of the warranty would we be talking about? a new car with a blown" rod knocking" What?
I think that's just nonsense and not even worthy of mental entertainment.
As you can see from reading posts here some guy uses low Octane in a lease vehicle.. turns it in, with low miles it will moe than likely be sold as CPO and then what? please with this fuel stuff.
Moral:
Don't be cheap. do what your sticker in your fuel door say's.
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From: CT
Mercedes, Porsche, BMW, Tesla
Does anyone find this odd? I've never seen any stations in LA with anything higher than 91. The thing I find odd about it, is that there are tons of MB's, BMW's, Ferrari's, Lambo's, etc in LA that all require something higher than 91... I do remember filling up once in Bakersfield and there was 93 available. I did feel quite a difference with it in my S550, but nothing substantial.
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04 S430 (sold),05 X5 4.4i, 02 325i, 87 560SL, 85 Alfa Romeo
Does anyone find this odd? I've never seen any stations in LA with anything higher than 91. The thing I find odd about it, is that there are tons of MB's, BMW's, Ferrari's, Lambo's, etc in LA that all require something higher than 91... I do remember filling up once in Bakersfield and there was 93 available. I did feel quite a difference with it in my S550, but nothing substantial.
the 126 is Ancient and so is VERY high octane premuim fuel.. Like everything else what we see today is a company that STILL is not up to date with the pulse of the world in so many ways...
BTW. when I mentioned the places in the world I meant this decade... I'm sure you did find many place with 93 and higher octane back in the day when premuim unleaded was called "Super" here in the US.
Nowadays the Octace rating is measured by the amount of ethanol that actally exists in the fuel (Read the sticker at the pump).. so all of the fuels we use today are "cut".
But who cares.. and I don't believe that carbon build up story either.. Neither would any other person who knows how engines realy work.. You know how many miles and how much abuse would have to occur for that to happen??? It's not even realistic..
Carbon build-up doesn't come from low octane fuel necessarily, but more from buildup of unburned fuel.. Detonation is the result of fuel buring too fast so how can that even logically make sense? not to mention the shear amount of carbon that would have to reside in a cylinder and how hard it would have to get in order to cause the damages you described, and it all happening withinn a waranty period...
I don't buy that and still stick to my opinion that even if it were possible I would NEVER see a shop be able to legally void a warranty as a result..
PLUS, if a bad engine is diagnosed, the entire engine is removed and replaced on a warranty because of the labor involved in a tearown and How many menz dealears do onsite rebuilds? none. That story is a dud.
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From: San Jose area
'19 E63S sedan
No. This booklet comes with every MB.
http://www.4shared.com/account/file/...y0xEvac3n49Lfl
http://www.4shared.com/account/file/...y0xEvac3n49Lfl
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Member
Joined: Feb 2008
Posts: 121
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From: Oxford, England
S430, SL500
Is there some sort of conversion between US "octane" and UK/Euro "octane" at all?
I ask because the cheap stuff here is sold as 95, with 97 and 99 being the premium grades. Confusing that its different over there, its the same all over europe here.
I ask because the cheap stuff here is sold as 95, with 97 and 99 being the premium grades. Confusing that its different over there, its the same all over europe here.
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Joined: Mar 2006
Posts: 4,278
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From: San Jose area
'19 E63S sedan
The reason for the difference is that there are two ways to measure octane, RON and MON. Europe uses RON. MON is the way aviation fuels are measured, and is more conservative. A fuel typically will test 10 points lower on the MON test than the RON test. US regulations require quoting the average of RON and MON, resulting in a 5 point difference.
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The only thing odd is how out of touch with reality that post and those stickers on your fuel door are.
the 126 is Ancient and so is VERY high octane premuim fuel.. Like everything else what we see today is a company that STILL is not up to date with the pulse of the world in so many ways...
BTW. when I mentioned the places in the world I meant this decade... I'm sure you did find many place with 93 and higher octane back in the day when premuim unleaded was called "Super" here in the US.
Nowadays the Octace rating is measured by the amount of ethanol that actally exists in the fuel (Read the sticker at the pump).. so all of the fuels we use today are "cut".
But who cares.. and I don't believe that carbon build up story either.. Neither would any other person who knows how engines realy work.. You know how many miles and how much abuse would have to occur for that to happen??? It's not even realistic..
Carbon build-up doesn't come from low octane fuel necessarily, but more from buildup of unburned fuel.. Detonation is the result of fuel buring too fast so how can that even logically make sense? not to mention the shear amount of carbon that would have to reside in a cylinder and how hard it would have to get in order to cause the damages you described, and it all happening withinn a waranty period...
I don't buy that and still stick to my opinion that even if it were possible I would NEVER see a shop be able to legally void a warranty as a result..
PLUS, if a bad engine is diagnosed, the entire engine is removed and replaced on a warranty because of the labor involved in a tearown and How many menz dealears do onsite rebuilds? none. That story is a dud.
the 126 is Ancient and so is VERY high octane premuim fuel.. Like everything else what we see today is a company that STILL is not up to date with the pulse of the world in so many ways...
BTW. when I mentioned the places in the world I meant this decade... I'm sure you did find many place with 93 and higher octane back in the day when premuim unleaded was called "Super" here in the US.
Nowadays the Octace rating is measured by the amount of ethanol that actally exists in the fuel (Read the sticker at the pump).. so all of the fuels we use today are "cut".
But who cares.. and I don't believe that carbon build up story either.. Neither would any other person who knows how engines realy work.. You know how many miles and how much abuse would have to occur for that to happen??? It's not even realistic..
Carbon build-up doesn't come from low octane fuel necessarily, but more from buildup of unburned fuel.. Detonation is the result of fuel buring too fast so how can that even logically make sense? not to mention the shear amount of carbon that would have to reside in a cylinder and how hard it would have to get in order to cause the damages you described, and it all happening withinn a waranty period...
I don't buy that and still stick to my opinion that even if it were possible I would NEVER see a shop be able to legally void a warranty as a result..
PLUS, if a bad engine is diagnosed, the entire engine is removed and replaced on a warranty because of the labor involved in a tearown and How many menz dealears do onsite rebuilds? none. That story is a dud.
91 R+M/2 octane premium is found only in a few places in the US, and it is completely "out of touch" with the rest of the world.
Throughout Europe, the LOWEST octane premium is equivalent to 94, some stations sell 96 instead of 94. Our 91 is European midgrade (RON 95)
Even throughout the US, most places sell 93 or 92 premium, Sunoco sells 94.
My service advisor is Jason Lewis at Calabasas MB, and they did not rebuild the engine, but they pulled the head to inspect it.
Member
Joined: Feb 2008
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From: Oxford, England
S430, SL500
Generally, the US octane rating is about 5 points lower than the same gasoline/petrol would have in Europe. European 91 or 92 is like US 87; European 95 is about US 90 or 91. This is the highest available in California. In some states you can find (US) 92 or 93, which would be about 98 European. The 100 octane fuel sometimes available in Europe is not generally available over here. A very few pumps provide US 100 ("racing fuel"), which is very expensive -- about twice the cost of our 91. This is about 106 European octane. I use a tank of this every now and then in my S65 and it makes a slight difference. An ECU tune calibrated to this fuel would be awesome, but would make the car pretty impractical. There is no 100-octane pump between San Jose and Los Angeles, for instance, and they are more than a tank apart.
The reason for the difference is that there are two ways to measure octane, RON and MON. Europe uses RON. MON is the way aviation fuels are measured, and is more conservative. A fuel typically will test 10 points lower on the MON test than the RON test. US regulations require quoting the average of RON and MON, resulting in a 5 point difference.
The reason for the difference is that there are two ways to measure octane, RON and MON. Europe uses RON. MON is the way aviation fuels are measured, and is more conservative. A fuel typically will test 10 points lower on the MON test than the RON test. US regulations require quoting the average of RON and MON, resulting in a 5 point difference.
FWIW i run cheap 95 (so 90 there), as i have found that in my S430 paying the extra for 99/102 makes absolutely no difference to either economy or noticable power. Engine still runs smooth as anything even with 40k/year being put on it, so it doesnt seem to be doing any harm.
Junior Member
Joined: Jul 2016
Posts: 23
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From: Central FL (eustis) between ocala n orlando
Clk320 convertible
Clk320 2001 can i use midvgrade or low grafe fule or i have to nuy the mostvexpensive. I recently lost my job and my clk320 convertible is my only vehicle what to do please help. My addy is agr8chef@yahoo.com
Super Member
Joined: May 2016
Posts: 516
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From: California
2018 C300
Check your manual, it'll let you know. Altering your driving style(speed limit or less, 3-4 seconds following distance, coast to a stop, etc.) will save you as much or more than a lower grade(depending on how aggressively you drive now.) Look up hypermiling, it's not any fun but it can save enough to count for a fair bit when money is that tight. Some who follow it strictly have been able to double the epa estimates.
Junior Member
Joined: Jul 2016
Posts: 23
Likes: 1
From: Central FL (eustis) between ocala n orlando
Clk320 convertible
Thanks well purchased car used and no manual came with it. Hell dont even know whst half the buttons are for in the car. Dont know how to check hydrolic fluid for drop top dont know alot of stuff. So if anyone has an inexpensive clk320 2001 convertible manul they wanna get rid of let me know. But thanks for the driving tip you are correct i was hoping mabye mid grade fuel would be ok???
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From: DFW
2 2001 E320s, 2005 E320 4Matic
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Mercedes
Mid grade or even 87 octane is fine
The clk320/s430/s500 will all work fine on 87. Mine has had 87 from day one in over 210k miles of driving . As the mb manual above states , only in mountainous Or hard driving is where the benefits of high octane are needed . In normal every day driving and commuting regular 87 is fine and you wont damage anything
The clk320/s430/s500 will all work fine on 87. Mine has had 87 from day one in over 210k miles of driving . As the mb manual above states , only in mountainous Or hard driving is where the benefits of high octane are needed . In normal every day driving and commuting regular 87 is fine and you wont damage anything
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From: Atlanta, GA
2001 S500 (W220) / 2007 GL450 (X164)
Mid grade or even 87 octane is fine
The clk320/s430/s500 will all work fine on 87. Mine has had 87 from day one in over 210k miles of driving . As the mb manual above states , only in mountainous Or hard driving is where the benefits of high octane are needed . In normal every day driving and commuting regular 87 is fine and you wont damage anything
The clk320/s430/s500 will all work fine on 87. Mine has had 87 from day one in over 210k miles of driving . As the mb manual above states , only in mountainous Or hard driving is where the benefits of high octane are needed . In normal every day driving and commuting regular 87 is fine and you wont damage anything
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From: Ball Ground, GA (N of Atlanta)
2003 S500 2007 GL450
"Good to know!"
Perhaps not...
You need to realize that some "discussions" on things automotive are religion, not engineering. These religious subject definitely include octane requirements, engine oil to use, how often to change oil, ATF to use, etc., etc. If you read the complete thread, you will discover an amazing amount of "information" that is just wrong.
Perhaps not...
You need to realize that some "discussions" on things automotive are religion, not engineering. These religious subject definitely include octane requirements, engine oil to use, how often to change oil, ATF to use, etc., etc. If you read the complete thread, you will discover an amazing amount of "information" that is just wrong.
Super Member
Joined: Nov 2018
Posts: 604
Likes: 16
From: Atlanta, GA
2001 S500 (W220) / 2007 GL450 (X164)
"Good to know!"
Perhaps not...
You need to realize that some "discussions" on things automotive are religion, not engineering. These religious subject definitely include octane requirements, engine oil to use, how often to change oil, ATF to use, etc., etc. If you read the complete thread, you will discover an amazing amount of "information" that is just wrong.
Perhaps not...
You need to realize that some "discussions" on things automotive are religion, not engineering. These religious subject definitely include octane requirements, engine oil to use, how often to change oil, ATF to use, etc., etc. If you read the complete thread, you will discover an amazing amount of "information" that is just wrong.
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Mercedes
It’s very simple , for the normally aspirated cars you can use 87 and just don’t race it - keep throttle below 2/3 and rpm below 3000. This is how 90% of people drive anyway . Most people report absolutely no benefit from higher octane in these Models without turbo or supercharger .
For the supercharged s55 and turbo s600, they will have substantial performance reduction and increased possibility of detonation so you really do benefit from 91/93.
For the supercharged s55 and turbo s600, they will have substantial performance reduction and increased possibility of detonation so you really do benefit from 91/93.
