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Hi

My years of mechanical training always taught us to run the lowest grade fuel you could use without pinging / detonation.
I hear the same from MB owners , but 10:1 compression unless your driver only, on flat ground driving , I would think midgrade fuel should be used ?.

Maybe the older 8.7:1 engines will run on most any fuel.

Uboater
 

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380sel 81
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Hi

My years of mechanical training always taught us to run the lowest grade fuel you could use without pinging / detonation.
I hear the same from MB owners , but 10:1 compression unless your driver only, on flat ground driving , I would think midgrade fuel should be used ?.

Maybe the older 8.7:1 engines will run on most any fuel.

Uboater
run gas that does not ping is fine. Older cars sometime have an increase in compresion so it pinging begins, move up to higher octane (more expensive for those who are not into octane) until pinging is gone. summer time is more likely to ping to. A overheated engin pings no matter what gas is used. Your altitude from sealevel give you options to.
higher altitude will run cheaper (low octean) gas. Three factors are in play beside the octane in the manual. I don,t go lower than the manual witch supperceeds anything i say by the way.
 

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2002 E320W4
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a newer car is very unlikely to ping regardless of what octane you use. this is because ...

a newer car is very unlikely to ping regardless of what octane you use. this is because of the knock sensor that will retard timing. but, a higher compression motor should always use at least 89 octane. it may be a dime more per gallon but its less costly in the long run.
 

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Hi

My years of mechanical training always taught us to run the lowest grade fuel you could use without pinging / detonation.
I hear the same from MB owners , but 10:1 compression unless your driver only, on flat ground driving , I would think midgrade fuel should be used ?.

Maybe the older 8.7:1 engines will run on most any fuel.

Uboater
The problem with your theory is that many newer cars have knock sensors that reduce the performance of an engine when lower octane fuel is used. If it is necessary to use a lower octane don't expect to get the full potential from your engine.
 

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86 560SEL
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I have never put anything less than premium in my cars and they have never ping regarding ...

I have never put anything less than premium in my cars and they have never ping regarding on how hot it is outside.
 

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Re: Re: How many of you run cheap -vs - premium fuel ?

The problem with your theory is that many newer cars have knock sensors that reduce the performance of an engine when lower octane fuel is used. If it is necessary to use a lower octane don't expect to get the full potential from your engine.
True, it will retard the timing so that performance isn't as rated on MB's website, but the difference is so minimal that it is barely noticible...of course unless u really can notice a few HP difference and put it on a dyno.
 

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Re: Re: Re: How many of you run cheap -vs - premium fuel ?

The problem with your theory is that many newer cars have knock sensors that reduce the performance of an engine when lower octane fuel is used. If it is necessary to use a lower octane don't expect to get the full potential from your engine.
True, it will retard the timing so that performance isn't as rated on MB's website, but the difference is so minimal that it is barely noticible...of course unless u really can notice a few HP difference and put it on a dyno.
My engine has 11:1 compression ratio. If you think it will run okay on 87 octane I have a bridge with a lovely view you'll love.

[}:)]
 

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96 S320, 89 560SL,
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I run premium in both of mine. I am told the 89 will ping if I use regular. What many people do not know is the pinging (detonation) is occuring before it becomes bad enough to hear. Over a long period of time this does serious damage to an engine.
The S320 would run on regular, the computer would simply retard the timing, but it has little enough power as it is....
 

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Widebody SEC
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garbage in garbage out

like health food for your car. i only use 94 octane in my car. would you put cheap fuel in a ferrari, aston martin or rolls? a mercedes is a better car than those [:D]. with 280,000kms i have never spent a cent on engine repairs.

it disappoints me when someone buys a mercedes then cuts corners on ownership [:(].

be practical not cheap.
 

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04 E55
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IN High altitude areas you can run Midgrade in place of premium because of the thinner air. I run Mid grade in all my cars that say premium ( gets better fuel economy ) in Colorado.
 

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Put premium fuel in if you wish but are you smarter then all those highly paid German engineers? If the book calls for 87 and you put 94 in, you're not doing your car any favors. There is no additional "power" in a gallon of premium compared to a gallon of regular. Use of high test fuel for prolonged periods could probably make it mandatory in the future since it would increase compression some by building up carbon in the combustion chamber as well as cause pinging because hot spots in the carbon build up would cause innapropriately timed ignition of the fuel. But I always say...if it makes you feel good...do it. It's your car and your money.
 

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E300POS - 12/17/2003 1:30 PM

Put premium fuel in if you wish but are you smarter then all those highly paid German engineers? If the book calls for 87 and you put 94 in, you're not doing your car any favors. There is no additional "power" in a gallon of premium compared to a gallon of regular. Use of high test fuel for prolonged periods could probably make it mandatory in the future since it would increase compression some by building up carbon in the combustion chamber as well as cause pinging because hot spots in the carbon build up would cause innapropriately timed ignition of the fuel. But I always say...if it makes you feel good...do it. It's your car and your money.
If the manufacturer calls for 87, you probably won't benefit from higher octane fuel unless conditoipons are adverse (high load and temps). However, your other assumption here is not valid. Running premium in a 4 stroke engine designed for regular does not leave more carbon deposits. There are many studies available from the US DOE that can help explain this as well as provide more information about engine damage from detonation. You might be thinking of a 2 stroke motor which can sometimes suffer from over cooling.

BTW, the amount of HP lost when the ECU retards timing is significant. PowerChip has some dyno tests that show as much 25-30HP when using 87 octane vs. 94. I don't know about your butt dyno, but mine can sure feel this much of a drop.
 

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1993 300E 3.2L 24V
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I run Mid-grade in my 93 300E, runs just fine. I wouldn't want to cut it to the 87, 87 can get bad fast, but I doubt it needs 94+. I was told my MB Mechanics and the guy I bought the car from who should get a medal or something for knowing Benzes, spefically the 300 series and they both said 89 is about the best for it, good fuel, okay price.

-Tubs
 

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I don't believe premium unleaded fuel was available in the United States until the mid 1980s, so any US market cars built prior to that time had to be able to use unleaded regular.
 

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drbb1 - 12/11/2003 8:26 AM
....
The S320 would run on regular, the computer would simply retard the timing, but it has little enough power as it is....
The book says 92, so its premium. Open your cars book and then make comments.
 

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I run 104 octane 24/7 in my toyota
94 octane in the benz
94 octane in my honda
87 octane in my saab- just because the company forces me too.

I noticed i did back to back comparison and eventhough my honda said 87 is fine i got 220 miles on a full tank. Now with 94 octane i get 320 miles. O2 sensor and everything else was the same. Even the same coolant. Now oxgenated gas has horrible mileage. My Toyota might get 12 mpg either that or it is because my right foot is heavy ;)
 
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