Update: Manganase Free
10-17-2003, 07:58 PM
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Update: Manganase Free
Hello. Okay, with no 'real' answer here from the forum, I decided to try the source and then share the information. The following is from Debbie Carr, Customer Relations Representive, Chevron Canada Limited:
>The scientific name for (Manganese) "MMT" is methylcyclopentadienyl manganese
>tricarbonyl. "MMT¨ is widely used in Canada as an octane enhancer in lead-free gasoline.
>All of our stations in the Lower Mainland, Vancouver Island and Sunshine Coast have
>Manganese-Free gasoline's. Also, all of our stations in the U.S. are Manganese-Free.
>Supreme Plus 94 is Manganese-Free at all of our stations in B.C. Chevron gasoline's
>produced in the Burnaby Refinery (BC) will be (is now) Manganese-Free.
>Several major automobile manufacturers have recommended car owners use Manganese-
>Free gasoline. Chevron Canada has made the decision to remove Manganese ("MMT¨) from >their gasolines in the Lower Mainland (BC), Vancouver Island and Sunshine Coast. Chevron >wants to offer our customers an alternative/option.
I guess everyone else in Canada still get gasolene with Maganese... my surmise is that Maganese was 'a' method to boost octane but some it 'might' harm the environment, so the company has switched (presumably with a different method now for octane enhancing....)
>The scientific name for (Manganese) "MMT" is methylcyclopentadienyl manganese
>tricarbonyl. "MMT¨ is widely used in Canada as an octane enhancer in lead-free gasoline.
>All of our stations in the Lower Mainland, Vancouver Island and Sunshine Coast have
>Manganese-Free gasoline's. Also, all of our stations in the U.S. are Manganese-Free.
>Supreme Plus 94 is Manganese-Free at all of our stations in B.C. Chevron gasoline's
>produced in the Burnaby Refinery (BC) will be (is now) Manganese-Free.
>Several major automobile manufacturers have recommended car owners use Manganese-
>Free gasoline. Chevron Canada has made the decision to remove Manganese ("MMT¨) from >their gasolines in the Lower Mainland (BC), Vancouver Island and Sunshine Coast. Chevron >wants to offer our customers an alternative/option.
I guess everyone else in Canada still get gasolene with Maganese... my surmise is that Maganese was 'a' method to boost octane but some it 'might' harm the environment, so the company has switched (presumably with a different method now for octane enhancing....)
10-18-2003, 09:07 AM
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Burning Brakes
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Bruce,
I think that's a common problem all over, also in Europe where we are using MTBE (Methyl Tertiary Butyl Ether) - See e.g. http://www.sacbee.com/24hour/politic...-7093445c.html
My car is build for octane 98, and that's hard to find now a days in Denmark, only few gasoline station are allowed to store this fuel in there underground storage tanks due the risk for water pollution
I think that's a common problem all over, also in Europe where we are using MTBE (Methyl Tertiary Butyl Ether) - See e.g. http://www.sacbee.com/24hour/politic...-7093445c.html
My car is build for octane 98, and that's hard to find now a days in Denmark, only few gasoline station are allowed to store this fuel in there underground storage tanks due the risk for water pollution
10-19-2003, 01:53 PM
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Burning Brakes
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IIRC,
MTBE is a an "oxegenator" additive, though it may have some octane boost as a secondary effect.
The oxegenated fuels are mandated by the EPA, in specific areas that need to meet certain clean air targets.
I was living in the Bay Area when (I think) it was first used. There were all sorts problems with cars when the MTBE first rolled out - never any conclusive link that I heard of, but it did seem a bit beyond the normal failure rates - especially for odd fuel system probs that you normally just don't see anymore.
Other than cost, I'm not sure why MTBE went forward. I'm even more confused/concerned that it is currently in use outside of CA. They were trying to ban it when I left years ago, because it started turning up just about everywhere - ground water, drinking water, ground samples.
Greg
MTBE is a an "oxegenator" additive, though it may have some octane boost as a secondary effect.
The oxegenated fuels are mandated by the EPA, in specific areas that need to meet certain clean air targets.
I was living in the Bay Area when (I think) it was first used. There were all sorts problems with cars when the MTBE first rolled out - never any conclusive link that I heard of, but it did seem a bit beyond the normal failure rates - especially for odd fuel system probs that you normally just don't see anymore.
Other than cost, I'm not sure why MTBE went forward. I'm even more confused/concerned that it is currently in use outside of CA. They were trying to ban it when I left years ago, because it started turning up just about everywhere - ground water, drinking water, ground samples.
Greg
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10-20-2003, 12:11 AM
#8
Nordschleife Master
MTBE is a ester of sorts. What is it, Methyl TetraButal Ester? I can't rember my organtic right now.
Anyways, pure MTBE has a very high octane rateing. Around 115. Very high, compared to toluene and benzene, at 106 or so.
For non-orgo metalic fuels, you can get a rough octane number by takeing the weighted average of the various componets. So, adding a small amount of MTBE results in a disproportantly large ocane rateing. It's very cheap to produce, and matchs the propertys of gasoline well. It doesn't have horrendous enviromental effect, compared to say some orgo matalic compounds. It also doesn't react poorly with most of the polymers used in fuel systems. A God send right?
However, there is a down side to MTBE. It can cause cancer.
It's also, as I understand it, containes fewer Carbon and hydrogen atoms per unit volume. This means that a non feed back system, (old school carbs and MFI) don't adjust for it, and still deliver the same volume of fuel. As a result, unless adjusted, they run lean. Thus the problems when it was first introduced. Systems with an O2 sensor don't have a problem, because the feed back loops corrects for it.
Next up is it's suppost to decompose to carbon in the presence of heat. Basicly, this means that it causes the intake valves to have carbon on them. This has been fixed by adding detergents to the gasoline that disolve away the carbon deposits.
Now that it's getting into the water supply, and want not, they're trying to reduce it's use. The alternatives are Benzene, Toluene, Ethanol, and probably a few more nasty ones. Benzene, and Toluene are equaly bad for the enviroment, and not cheap eighter. Ethanol has been around for years. I foget why they don't use it instead of MTBE.
Anyways, pure MTBE has a very high octane rateing. Around 115. Very high, compared to toluene and benzene, at 106 or so.
For non-orgo metalic fuels, you can get a rough octane number by takeing the weighted average of the various componets. So, adding a small amount of MTBE results in a disproportantly large ocane rateing. It's very cheap to produce, and matchs the propertys of gasoline well. It doesn't have horrendous enviromental effect, compared to say some orgo matalic compounds. It also doesn't react poorly with most of the polymers used in fuel systems. A God send right?
However, there is a down side to MTBE. It can cause cancer.
It's also, as I understand it, containes fewer Carbon and hydrogen atoms per unit volume. This means that a non feed back system, (old school carbs and MFI) don't adjust for it, and still deliver the same volume of fuel. As a result, unless adjusted, they run lean. Thus the problems when it was first introduced. Systems with an O2 sensor don't have a problem, because the feed back loops corrects for it.
Next up is it's suppost to decompose to carbon in the presence of heat. Basicly, this means that it causes the intake valves to have carbon on them. This has been fixed by adding detergents to the gasoline that disolve away the carbon deposits.
Now that it's getting into the water supply, and want not, they're trying to reduce it's use. The alternatives are Benzene, Toluene, Ethanol, and probably a few more nasty ones. Benzene, and Toluene are equaly bad for the enviroment, and not cheap eighter. Ethanol has been around for years. I foget why they don't use it instead of MTBE.
10-20-2003, 01:04 PM
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Burning Brakes
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VU,
Depending on where you are on the planet, your gasoline will contain a fair to relatively large percentage of light aromatics - these would include toluene and benzine - they are already in the gas in the pump just about everywhere.
I used to have a site that gave the breakdown by country of gasoline contents, now I can't find it. Ugh. I think someone linked a similar site in an old thread on using toluene to boost octane.
According to everything I've read, MTBE was introduced as an oxygenate. Why didn't they use ethanol? Probably cost, and the fact that alcohol absorbs water like brake fluid can't make it any easier to deal with.
Greg
Depending on where you are on the planet, your gasoline will contain a fair to relatively large percentage of light aromatics - these would include toluene and benzine - they are already in the gas in the pump just about everywhere.
I used to have a site that gave the breakdown by country of gasoline contents, now I can't find it. Ugh. I think someone linked a similar site in an old thread on using toluene to boost octane.
According to everything I've read, MTBE was introduced as an oxygenate. Why didn't they use ethanol? Probably cost, and the fact that alcohol absorbs water like brake fluid can't make it any easier to deal with.
Greg
10-20-2003, 02:33 PM
#11
Nordschleife Master
I know gasoline includes light aromatics. I thought the amount of toluene and benzene was usualy rather small. Thus, not major influances on the octane rateing. Not compared to MTBE. My understanding is that they come out of the "gasoline" fraction of the distilling. Basicly, my understanding is that they arn't normaly added to increase the octane rateing, while MTBE is added.
Lets see, 1 part toluene two 3 aprts gasoline, thats a about 25% by volume. I woulder what that works out to by mass. I could figure it out if I wanted, but I'm brain dead at the moment.
MTBE does as far as I can tell, does good things for the octane rateing, and this is why it was introduced, first. The oxygenate thing seems a bit weird to me, as you should beable to get the same effect of an oxygenate fuel by running a leaner mixture. I'm not exactly sure what they'er going for with this.
Lets see, 1 part toluene two 3 aprts gasoline, thats a about 25% by volume. I woulder what that works out to by mass. I could figure it out if I wanted, but I'm brain dead at the moment.
MTBE does as far as I can tell, does good things for the octane rateing, and this is why it was introduced, first. The oxygenate thing seems a bit weird to me, as you should beable to get the same effect of an oxygenate fuel by running a leaner mixture. I'm not exactly sure what they'er going for with this.
