Why no 91 Octane available? - Page 4 - Mercedes-Benz Forum

Reply
 
LinkBack Thread Tools Display Modes
post #31 of 38 (permalink) Old 01-25-2007, 07:55 AM
Lifetime Premium Member
 
Musikmann's Avatar
 
Date registered: May 2006
Vehicle: 2001 E320 - Brilliant Silver/Ash: 107,000+
Location: West Virginia, USA
Posts: 17,193
Mentioned: 0 Post(s)
Quoted: 6 Post(s)
Lifetime Premium Member
Different gas types

Quote:
Originally Posted by one.bofh
...I think I am going to stop experimenting with different gas types and just stick to the same pure 91 octane.
I'm probably neurotic (as in OCD) but I always use the same brand too. I found one that I like, Chevron, and I can always find a station. The primary reason is that they have never used ethanol as an additive. We used to have an ethanol plant around here and at the time I started using that, "pure" gas was hard to find here.

Mercedes Benz - Das beste oder nichts!
Musikmann is offline  
Sponsored Links
Advertisement
 
post #32 of 38 (permalink) Old 01-25-2007, 08:19 AM
Lifetime Premium Member
 
Musikmann's Avatar
 
Date registered: May 2006
Vehicle: 2001 E320 - Brilliant Silver/Ash: 107,000+
Location: West Virginia, USA
Posts: 17,193
Mentioned: 0 Post(s)
Quoted: 6 Post(s)
Lifetime Premium Member
Question Emissions

Quote:
Originally Posted by marlinspike
...It's funny that ethanol is popular among tree huggers (and I agree that it is). More NOx output, more evaporative emissions, sometimes more HC emissions, is corrosive to rubber which will lead to more emissions in the future (since people will surely keep their cars running less than perfect rather than replace the seals).
Ditto again and as far as I know, by using ethanol we are just adding another set of noxious emission chemicals on top of the other - is that really solving anything? (global warming, ozone depletion, yada yada).

I'm not at all convinced that the ethanol gasolines are any "better" for the environment. Maybe I need to be reading more?

Mercedes Benz - Das beste oder nichts!

Last edited by Musikmann; 01-25-2007 at 08:56 AM.
Musikmann is offline  
post #33 of 38 (permalink) Old 01-26-2007, 03:22 AM
BenzWorld Member
 
Borini63's Avatar
 
Date registered: Jan 2007
Vehicle: 1973 W115 220 Sedan Auto,1984 500SEC 274K,1988 MB 560SEC 207K on the clock
Location: Phoenix AZ USA
Posts: 147
Mentioned: 0 Post(s)
Quoted: 1 Post(s)
Ok...what will happen if I use a 89 octan in my 1988 560SEC?
Borini63 is offline  
post #34 of 38 (permalink) Old 01-26-2007, 08:09 AM
Lifetime Premium Member
 
Musikmann's Avatar
 
Date registered: May 2006
Vehicle: 2001 E320 - Brilliant Silver/Ash: 107,000+
Location: West Virginia, USA
Posts: 17,193
Mentioned: 0 Post(s)
Quoted: 6 Post(s)
Lifetime Premium Member
Hard to say, unless you give it a try. Is there no indication anywhere on your car, or in your owner's manual, which grade was recommended in 1988?

Mercedes Benz - Das beste oder nichts!
Musikmann is offline  
post #35 of 38 (permalink) Old 01-26-2007, 08:26 AM
BenzWorld Elite
 
marlinspike's Avatar
 
Date registered: Feb 2005
Vehicle: 1985 380SE
Location: Davidson, NC & DC area
Posts: 1,294
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
I forget what the 560SEC's wanted, but IIRC it's 91. If that's the case, do not use 89. I know the 380 is pre-knock sensor and I think the 560 is as well. That would mean using 89 wouldn't simply reduce power and fuel mileage, it could also cause pinging and or detonation and destroy your engine.
marlinspike is offline  
post #36 of 38 (permalink) Old 01-27-2007, 12:41 AM
BenzWorld Member
 
Date registered: Dec 2006
Vehicle: 2001 C320
Location: Los Angeles
Posts: 52
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
I live in LA, 91 is available everywhere here.
wfl225 is offline  
post #37 of 38 (permalink) Old 01-27-2007, 01:40 AM
BenzWorld Member
 
Borini63's Avatar
 
Date registered: Jan 2007
Vehicle: 1973 W115 220 Sedan Auto,1984 500SEC 274K,1988 MB 560SEC 207K on the clock
Location: Phoenix AZ USA
Posts: 147
Mentioned: 0 Post(s)
Quoted: 1 Post(s)
Then I should use 91 octane....we have it here in Phoenix Arizona.....
Borini63 is offline  
post #38 of 38 (permalink) Old 01-27-2007, 11:19 AM
BenzWorld Extremist
 
one.bofh's Avatar
 
Date registered: Jul 2006
Vehicle: 2008 C230 4MATIC; 2008 ML320 CDI 4MATIC
Location: Toronto, Canada
Posts: 819
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
Reading more is good

Quote:
Originally Posted by Musikmann
Ditto again and as far as I know, by using ethanol we are just adding another set of noxious emission chemicals on top of the other - is that really solving anything? (global warming, ozone depletion, yada yada).

I'm not at all convinced that the ethanol gasolines are any "better" for the environment. Maybe I need to be reading more?
Looks like you may need to be reading more (apparently I needed to read more as well). Good piece of information about ethanol of Wikipedia (Ethanol fuel) - Wikipedia, the free encyclopedia.

Looks like it is true that:
- Ethanol burns cleanly thus reducing pollution compared to gasoline.
- Ethanol produces less power, and therefore mileage is reduced when using fuels with ethanol.

Here are the relevant paragraphs from the article:
Air pollution

Compared with conventional unleaded gasoline, ethanol is a particulate-free burning fuel source that combusts cleanly with oxygen to form carbon dioxide and water:
C2H5OH + 3 O2 → 2 CO2 + 3 H2O + heat The Clean Air Act requires the addition of oxygenates to reduce carbon monoxide emissions in the United States. The additive MTBE is currently being phased out due to ground water contamination, hence ethanol becomes an attractive alternative additive.
Use of ethanol, produced from current (2006) methods, emits a similar amount of carbon dioxide but less carbon monoxide than gasoline.[38] If all bioethanol-production energy came from non-fossil sources the use of bioethanol as a fuel would add no greenhouse gas.[39]
In considering the potential for pollution reduction with ethanol, however, it is equally important to consider the potential for environmental contamination stemming from the manufacture of ethanol. In 2002, monitoring of ethanol plants revealed that they released VOCs (volatile organic compounds) at a higher rate than had previously been disclosed.[40] The Environmental Protection Agency (EPA) subsequently reached settlement with Archer Daniels Midland and Cargill, two of the largest producers of ethanol, to reduce emission of these VOCs. VOCs are produced when fermented corn mash is dried for sale as a supplement for livestock feed. Devices known as thermal oxidizers or catalytic oxidizers can be attached to the plants to burn off the hazardous gases.



Fuel Economy

For vehicles with current (2006) design flexible fuel engines, fuel economy (measured as miles per gallon (MPG), or liters per 100 km) is directly proportional to energy content.[25] Ethanol contains approx. 34% less energy per gallon than gasoline, and therefore will result in a 34% reduction in miles per gallon[26][27]. For E10 (10% ethanol and 90% gasoline), the effect is small (~3%) when compared to conventional gasoline, and even smaller (1-2%) when compared to oxygenated and reformulated blends.[28] However, for E85 (85% ethanol), the effect becomes significant. E85 will produce approximately 27% lower mileage than gasoline, and will require more frequent refueling. Actual performance may vary depending on the vehicle.

Hydrated ethanol × gasoline type C price table for use in Brazil


For the EPA-rated mileage of current USA flex-fuel vehicles, see.[29]
This reduced fuel economy should be considered when making price comparisons. For example, if regular gasoline costs $3.00 per gallon, and E85 costs $2.19 per gallon, the prices are essentially equivalent. If the discount for E85 is less than 27%, it actually costs more per mile to use. For USA price comparisons, see.[30]
Some researchers are working to increase fuel efficiency by optimizing engines for ethanol-based fuels. Ethanol's higher octane allows an increase of an engine's compression ratio for increased thermal efficiency.[31] In one study, complex engine controls and increased exhaust gas recirculation allowed a compression ratio of 19.5 with fuels ranging from neat ethanol to E50. Thermal efficiency up to approximately that for a diesel was achieved.[32] This would result in the MPG of a dedicated ethanol vehicle to be about the same as one burning gasoline. There are currently no commercially-available vehicles that make significant use of ethanol-optimizing technologies, but this may change in the future.

92% of all people suck at math. I am a part of the 9% who don't.

Current Cars:
2008 ML320 CDI 4MATIC (W164) - Silver/Black
2008 C230 4MATIC (W204) - White/Black

Past Cars:
2002 E320 (W210) - Silver/Black - Sold due to rust
one.bofh is offline  
Sponsored Links
Advertisement
 
Reply

  Mercedes-Benz Forum > General Mercedes-Benz Forums > General Mercedes-Benz

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Mercedes-Benz Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in











  • Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
     
    Thread Tools
    Show Printable Version Show Printable Version
    Email this Page Email this Page
    Display Modes
    Linear Mode Linear Mode



    Similar Threads
    Topic Author Forum Replies Last Post
    I use 87 octane now! jeffinski W211 E-Class 53 07-29-2008 04:44 PM
    Octane? mgill85258 W126 S,SE,SEC,SEL,SD,SDL Class 6 11-07-2006 10:23 AM
    Sunoco 91/94 octane vs. Shell V-Power 91 octane JBeans General Mercedes-Benz 4 11-13-2005 03:22 PM
    91 octane $2.73? slkpwr R170 SLK-Class 9 04-02-2005 10:34 AM
    Follow up to Poll - Is Octane booster OK, if 94 Octane not available ? LelloSLK R170 SLK-Class 11 04-23-2002 06:55 PM

    Posting Rules  
    You may post new threads
    You may post replies
    You may not post attachments
    You may not edit your posts

    BB code is On
    Smilies are On
    [IMG] code is On
    HTML code is Off
    Trackbacks are On
    Pingbacks are On
    Refbacks are On

     

    Title goes here

    close
    video goes here
    description goes here. Read Full Story
    For the best viewing experience please update your browser to Google Chrome