What kind of gas do you use?
10-18-2007, 08:34 PM
#27
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E550 4MATIC
I completely agree. These threads always baffle me. Why would anyone even try to put regular when the people who make the car tell you specifically to put premium? The savings is small, and I agree that if you are that desperate to save a few hundred dollars perhaps Mercedes is not for you.
10-18-2007, 09:23 PM
#28
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2008 C300 Sport, RWD, US
I completely agree. These threads always baffle me. Why would anyone even try to put regular when the people who make the car tell you specifically to put premium? The savings is small, and I agree that if you are that desperate to save a few hundred dollars perhaps Mercedes is not for you.
This is my first MB and I was a little shocked at what the service on this toy is going to cost me. Then again, its either spend it on this luxury or leave it to someone else in my will and well, you see which one I chose.
Back to the original question, I'm putting 91 octane in my C300 as per instructions. The gas station I use has premium going up to 93 octane. My understanding is that anything above a rated octane requirement doesn't help anything.
Last edited by JimPap; 10-18-2007 at 09:26 PM.
10-18-2007, 10:30 PM
#29
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'08 C300 Lux Barolo Red Beige Leather P2 MM 18" wheels '84 944
E10?
<<Don't worry, every gas station everywhere has switched to it. The cars can handle it.>>
I'm not worried because the only gasoline brand containing ethanol in Washington State is Arco. We are part of everywhere, BTW.
I'm using Chevron at the moment.
I'm not worried because the only gasoline brand containing ethanol in Washington State is Arco. We are part of everywhere, BTW.
I'm using Chevron at the moment.
10-19-2007, 12:05 AM
#31
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E550 4MATIC
That's what I was thinking too.
This is my first MB and I was a little shocked at what the service on this toy is going to cost me. Then again, its either spend it on this luxury or leave it to someone else in my will and well, you see which one I chose.
Back to the original question, I'm putting 91 octane in my C300 as per instructions. The gas station I use has premium going up to 93 octane. My understanding is that anything above a rated octane requirement doesn't help anything.
This is my first MB and I was a little shocked at what the service on this toy is going to cost me. Then again, its either spend it on this luxury or leave it to someone else in my will and well, you see which one I chose.
Back to the original question, I'm putting 91 octane in my C300 as per instructions. The gas station I use has premium going up to 93 octane. My understanding is that anything above a rated octane requirement doesn't help anything.
I feel like MB wouldn't say use premium if the cars really didn't need it because buying premium doesn't help their bottom line. In fact if they ran on regular, that could be an advantage becuase they could win over a few more buyers if they could advertise that their cars run on regular, like the new CTS.
Service costs are more annoying to me because I do have a problem spending more money than is necissary for something. The cars are designed to run on premium because this makes better performance and better emissions so the increased cost brings increased benefit. But paying over $100 for an oil change does not bring extra benefit.
10-19-2007, 12:30 AM
#32
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'08 C300 Lux Barolo Red Beige Leather P2 MM 18" wheels '84 944
10% ethanol
We have plenty of experience with 10% ethanol in certain zip codes mandated by the EPA in Washington State but that's been over for at least 5-7 years, maybe longer, when EPA air pollution goals were met. Arco adds ethanol purely for their profit.
Each year, on my first tank of E10 (term didn't exist then) my fuel mileage dropped 10% and in the Spring when it was removed, mileage went up 10%. Regular as clockwork. Performance was noticeably down also.
Of course, my new C300 is a flex-fuel vehicle but I have no plans to use E85 even if it were available in my area which it isn't.
Each year, on my first tank of E10 (term didn't exist then) my fuel mileage dropped 10% and in the Spring when it was removed, mileage went up 10%. Regular as clockwork. Performance was noticeably down also.
Of course, my new C300 is a flex-fuel vehicle but I have no plans to use E85 even if it were available in my area which it isn't.
10-22-2007, 12:33 AM
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2008 C350 Sport, Black on Black
imo ... If you got the dough to get a Benz, then you must have the extra $3.40 between fill-ups.
"Around here, you gotta love what you drive"
"Around here, you gotta love what you drive"
10-22-2007, 02:16 AM
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if you have enough money to get e MB, u gotta have enough money to spend less than $5 extra depending on gas prices between fill ups. MB requires 91 and + oct. rating fuel. The best fuel I can find in my area that all gas stations have it is 91! The only place I have seen a rating of higher than 91 is a gas station in West Los Angeles on the corner of Barrignton and Pico and they offer "racing fuel" with a rating of 100. the price, ove $8!
10-22-2007, 11:31 AM
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2008 C350
the standard premium around my parts is 93...with some stations having an additional option for 95 octane...
the car should be very happy with the 93...
the car should be very happy with the 93...
10-22-2007, 07:06 PM
#37
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LOADED 08' C350 & 14' GLK-350 Diamond White (P1, MM, AMG Pkg, Ln Trkng, Htd Sts, Keylss Go)
i have seen racing fuel with 100+ octane as well at my gas station... If i put this in my benzo, will it increase performance or is it not good for this engine???
10-24-2007, 04:40 PM
#38
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02 320e 37,000 miles 93 300e 3.2 liter 221,000 previous 89 300e 200,000
3 benze later 89 fuel
I have had 3 mb over the last 18 years
a 1988 300e 3.0 liter 200K always ran hot (just shy of red) and had oil leak
A 1989 300e 3.0 liter 180K ran great totaled in accident.
A 1993 300e 3.2 liter trading it after 9 years 225K, runs on the warm side,
has an oil leak. about a qt of oil for 500 - 750 miles. I see spots on the ground.
I tested each with 91 vs 89. They all ran equally well on both, same mileage and
same pep. I therefore ran the majority of miles on 89.
Each car had between 50 - 70 K when I got it.
Now I'm getting a 2002 and will test it the same way.
a 1988 300e 3.0 liter 200K always ran hot (just shy of red) and had oil leak
A 1989 300e 3.0 liter 180K ran great totaled in accident.
A 1993 300e 3.2 liter trading it after 9 years 225K, runs on the warm side,
has an oil leak. about a qt of oil for 500 - 750 miles. I see spots on the ground.
I tested each with 91 vs 89. They all ran equally well on both, same mileage and
same pep. I therefore ran the majority of miles on 89.
Each car had between 50 - 70 K when I got it.
Now I'm getting a 2002 and will test it the same way.
10-24-2007, 05:36 PM
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c300
The actual science behind octane is just that the higher the octane rating, the lower the temperature at which it combusts. (that a real word? ) Lower octane ratings mean that the cylinder wall temp will be higher, which can lead to "knock", aka pre-detonation. This is when fuel combusts before it is supposed to due to the higher temps in the cylinder. No biggee because all engines since spandex went out of style have knock sensors (don't know when exactly, but it's been a long time) that will dial back the ignition timing to prevent the knock.
So while it's perfectly safe to do so, running a lower octane than the engine was designed for probably isn't netting you the best performance if the timing gets dialed way back. My personal experience has been that if the motor is "high strung" (has a high-ish compression ratio) running lower octane gas usually results in a some nasty pinging and knocking on big hills when you stomp the gas. Most times though, if you had the stereo on you'd never know the difference.
Really depends on your tolerance for such things, and how much you feel like you're saving.
) Lower octane ratings mean that the cylinder wall temp will be higher, which can lead to "knock", aka pre-detonation. This is when fuel combusts before it is supposed to due to the higher temps in the cylinder. No biggee because all engines since spandex went out of style have knock sensors (don't know when exactly, but it's been a long time) that will dial back the ignition timing to prevent the knock.So while it's perfectly safe to do so, running a lower octane than the engine was designed for probably isn't netting you the best performance if the timing gets dialed way back. My personal experience has been that if the motor is "high strung" (has a high-ish compression ratio) running lower octane gas usually results in a some nasty pinging and knocking on big hills when you stomp the gas. Most times though, if you had the stereo on you'd never know the difference.
Really depends on your tolerance for such things, and how much you feel like you're saving.
10-24-2007, 05:51 PM
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E550 4MATIC
The actual science behind octane is just that the higher the octane rating, the lower the temperature at which it combusts. (that a real word? ) Lower octane ratings mean that the cylinder wall temp will be higher, which can lead to "knock", aka pre-detonation. This is when fuel combusts before it is supposed to due to the higher temps in the cylinder. No biggee because all engines since spandex went out of style have knock sensors (don't know when exactly, but it's been a long time) that will dial back the ignition timing to prevent the knock.
So while it's perfectly safe to do so, running a lower octane than the engine was designed for probably isn't netting you the best performance if the timing gets dialed way back. My personal experience has been that if the motor is "high strung" (has a high-ish compression ratio) running lower octane gas usually results in a some nasty pinging and knocking on big hills when you stomp the gas. Most times though, if you had the stereo on you'd never know the difference.
Really depends on your tolerance for such things, and how much you feel like you're saving.
) Lower octane ratings mean that the cylinder wall temp will be higher, which can lead to "knock", aka pre-detonation. This is when fuel combusts before it is supposed to due to the higher temps in the cylinder. No biggee because all engines since spandex went out of style have knock sensors (don't know when exactly, but it's been a long time) that will dial back the ignition timing to prevent the knock.So while it's perfectly safe to do so, running a lower octane than the engine was designed for probably isn't netting you the best performance if the timing gets dialed way back. My personal experience has been that if the motor is "high strung" (has a high-ish compression ratio) running lower octane gas usually results in a some nasty pinging and knocking on big hills when you stomp the gas. Most times though, if you had the stereo on you'd never know the difference.
Really depends on your tolerance for such things, and how much you feel like you're saving.
What you wrote mirrors other things I have read that you aren't saving any money using lower octane gas because you just get less mileage, resulting in higher gas comsumption.
10-24-2007, 06:32 PM
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a quarter mile at a time
The actual science behind octane is just that the higher the octane rating, the lower the temperature at which it combusts. (that a real word? ) Lower octane ratings mean that the cylinder wall temp will be higher, which can lead to "knock", aka pre-detonation. This is when fuel combusts before it is supposed to due to the higher temps in the cylinder. No biggee because all engines since spandex went out of style have knock sensors (don't know when exactly, but it's been a long time) that will dial back the ignition timing to prevent the knock.
So while it's perfectly safe to do so, running a lower octane than the engine was designed for probably isn't netting you the best performance if the timing gets dialed way back. My personal experience has been that if the motor is "high strung" (has a high-ish compression ratio) running lower octane gas usually results in a some nasty pinging and knocking on big hills when you stomp the gas. Most times though, if you had the stereo on you'd never know the difference.
Really depends on your tolerance for such things, and how much you feel like you're saving.
) Lower octane ratings mean that the cylinder wall temp will be higher, which can lead to "knock", aka pre-detonation. This is when fuel combusts before it is supposed to due to the higher temps in the cylinder. No biggee because all engines since spandex went out of style have knock sensors (don't know when exactly, but it's been a long time) that will dial back the ignition timing to prevent the knock.So while it's perfectly safe to do so, running a lower octane than the engine was designed for probably isn't netting you the best performance if the timing gets dialed way back. My personal experience has been that if the motor is "high strung" (has a high-ish compression ratio) running lower octane gas usually results in a some nasty pinging and knocking on big hills when you stomp the gas. Most times though, if you had the stereo on you'd never know the difference.
Really depends on your tolerance for such things, and how much you feel like you're saving.
Octane ratings for gas describe the volitity of that gas under compression to detonate. So a higher octane gas will not pre-detonate like a lower octane gas will. This is very important for engines with high compression, agressive timing, and forced induction. Pre-detonation is when gas starts to combust, before desired, so preceding the spark from the spark plug. Pre-detonation is what causes knock. It's true that knock sensors will retard timing to prevent damage to an engine if lower octane fuels are used. So while you won't necessarily hurt your engine by fulling up with cheaper gas, you will lose a slight bit of performance.
FYI - not all modern engines have knock sensors. If a manufacturer tunes an engine for low octane gas, it may not require a knock sensor. An example of this is Honda's J30A1 - 3.0L V6, used up until 2002 at least, maybe longer. It does not require premium unleaded, therefore it does not have a knock sensor.
Last edited by e1000; 10-24-2007 at 06:34 PM.
10-24-2007, 06:37 PM
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While an engine has knock sensors to protect itself, it is not simply safe to run on inferior fuel. There still may be pre-ignition, and the continued retarded timing and lower combustion can lead to carbon buildup at the very least.
How cheap and/or stupid are people? The fuel requirement is not there for decoration, nor does it help MB sell cars.
How cheap and/or stupid are people? The fuel requirement is not there for decoration, nor does it help MB sell cars.
10-24-2007, 09:27 PM
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c300
Octane ratings for gas describe the volitity of that gas under compression to detonate. So a higher octane gas will not pre-detonate like a lower octane gas will. This is very important for engines with high compression, agressive timing, and forced induction. Pre-detonation is when gas starts to combust, before desired, so preceding the spark from the spark plug. Pre-detonation is what causes knock. It's true that knock sensors will retard timing to prevent damage to an engine if lower octane fuels are used. So while you won't necessarily hurt your engine by fulling up with cheaper gas, you will lose a slight bit of performance.
10-24-2007, 09:54 PM
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E550 4MATIC
I know, I just don't get it. The fuel requirement is the one thing I actually do believe from MB because they have no financial incentive for you to buy more gas. It would be to their benefit if they did tell everyone to put regular because then they could make more money from repairs.
10-24-2007, 11:00 PM
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I'll be quite honest with you. If you have to save that 3 dollars and go get inferior gasoline like 89 octane, then you obviously should not be driving a Mercedes Benz. The manual states that if you have to use inferior gasoline, do it minimally and don't fill it up. Don't plan on ever running under 91 octane with this car. Not even my SUBARU IMPREZA allowed me to go lower than 91 octane.
