What is MMT?
Thread Starter
Burning Brakes
Joined: Feb 2005
Posts: 752
Likes: 1
From: Tulsa OK
What is MMT?
What is the MMT that is used in many Octane Booster products and why is it recommended that it not be used in a corvette?
The brand of gas I have been using is 93 Octane. The car runs great but yesterday when I went to fill up the 93 was gone and they now only have 91 as the highest octane. 91 will probably be fine but was wondering about the safety of octane boosters. They all seem to have MMT on the label.
Also, they were selling the 91 for what the 93 used to cost.
Anyone know anything about octane boosters?
The brand of gas I have been using is 93 Octane. The car runs great but yesterday when I went to fill up the 93 was gone and they now only have 91 as the highest octane. 91 will probably be fine but was wondering about the safety of octane boosters. They all seem to have MMT on the label.
Also, they were selling the 91 for what the 93 used to cost.
Anyone know anything about octane boosters?
Instructor
Joined: Dec 2004
Posts: 166
Likes: 0
Originally Posted by EStreeter
What is the MMT that is used in many Octane Booster products and why is it recommended that it not be used in a corvette?
The brand of gas I have been using is 93 Octane. The car runs great but yesterday when I went to fill up the 93 was gone and they now only have 91 as the highest octane. 91 will probably be fine but was wondering about the safety of octane boosters. They all seem to have MMT on the label.
Also, they were selling the 91 for what the 93 used to cost.
Anyone know anything about octane boosters?
The brand of gas I have been using is 93 Octane. The car runs great but yesterday when I went to fill up the 93 was gone and they now only have 91 as the highest octane. 91 will probably be fine but was wondering about the safety of octane boosters. They all seem to have MMT on the label.
Also, they were selling the 91 for what the 93 used to cost.
Anyone know anything about octane boosters?
i use MMT in my c5, no problems
Racer
Joined: Feb 2001
Posts: 298
Likes: 1
From: San Antonio Texas
MMT is a fairly aggressive solvent type chemical. I can't remember the exact full name - is is a very long one, though. In non-technical terms is it methyl-ethyl-bat**** (a common environmental term in my trade).
Running heavy doses in a C5 over a long period of time can cause O-rings, and other seals in the fuel system, to fail. At least that is what I've been told, and it does make sense. Limited use would not be a problem.
Unless you have a lot of mods, running 91 octane will be just fine. You can even get by with a little lower octane in a pinch. With our heads & cam package (heads were milled), we are running higher than stock compression ratio. We run just fine with 91 octane, which is the best we can buy at the pumps here. For autocrossing I add a can of octane booster to the tank to avoid "computer intervention" to reduce pinging. For daily driving it is fine without the booster.
Our car does run better with 93 octane, as we have found out druing some road trips to the midwest where you can get it. The computer doesn't "intervene" to reduce pinging with it.
Running heavy doses in a C5 over a long period of time can cause O-rings, and other seals in the fuel system, to fail. At least that is what I've been told, and it does make sense. Limited use would not be a problem.
Unless you have a lot of mods, running 91 octane will be just fine. You can even get by with a little lower octane in a pinch. With our heads & cam package (heads were milled), we are running higher than stock compression ratio. We run just fine with 91 octane, which is the best we can buy at the pumps here. For autocrossing I add a can of octane booster to the tank to avoid "computer intervention" to reduce pinging. For daily driving it is fine without the booster.
Our car does run better with 93 octane, as we have found out druing some road trips to the midwest where you can get it. The computer doesn't "intervene" to reduce pinging with it.
Race Director
Joined: Jul 2004
Posts: 16,795
Likes: 62
From: Lake Havasu City, AZ
Here is what MMT is : methylcyclopentadienyl manganese tricarbonyl)
The issue from a GM perpsective is rumors about it fouling the OBD II system. The EPA has concends because manganese is a neurotoxin...
MMT is a gasoline octane enhancer produced by the Ethyl Corporation. MMT is allowed in U.S. gasoline at a level equivalent to 1/32 grams per gallon manganese (gpg Mn).
In its decision on the use of MMT in the U.S., the Agency determined that MMT added at 1/32 gpg MN will not cause or contribute to regulated emissions failures of vehicles. Some have expressed concerns that the use of MMT may harm on-board diagnostic equipment (OBD) which monitors the performance of emissions control devices in the vehicle. As of this time, the Agency believes the data collected is inconclusive with regard to OBD.
Manganese is a neurotoxin and can cause irreversible neurological disease at high levels of inhalation. However, ingested manganese is a required element of the diet at very low levels. There is a concern that the use of manganese additives in gasoline could increase inhalation manganese exposures.
After completing a risk evaluation in 1994 on the use of MMT in gasoline, EPA was unable, based on the available data, to determine if these is a risk to the public health from exposure to emissions of MMT gasoline. The Agency stated "Although it is not possible based on the present information to conclude whether specific adverse health effects will be associated with manganese exposures in the vicinity of or exceeding the [estimated safe level over a lifetime of exposure], neither is it possible to conclude that adverse health effects will not be associated with such exposures." This assessment was based upon the level of MMT allowed in U.S. gasoline.
More specifically, modeling indicates that, as a result of MMT use in unleaded gasoline, certain portions of the population may be exposed to levels in the same range as the Reference Concentration (RfC or safe level for a lifetime exposure with an order of magnitude uncertainty). Because the expected exposure is not much higher or much lower than the RfC, a definitive conclusion about risk is impossible to reach. Long-term animal testing and exposure research are needed to more accurately define the risk.
Under Clean Air Act authority to require testing of motor fuels and additives, EPA has required the Ethyl Corporation to perform testing to help fill in data gaps and potentially provide information that would result in a more definitive risk evaluation. After submission of this additional information late in 2004, the Agency will study the results. The Agency may then be able to refine its risk evaluation or may ask for further testing based upon the results of the testing now being performed.
With funding from Ethyl Corporation, Research Triangle Institute (RTI) has also completed a study of manganese exposures in Toronto, Canada where MMT is used. The Agency is evaluating this study to determine what impact it might have on any evaluation of risk associated with use of the additive.
The issue from a GM perpsective is rumors about it fouling the OBD II system. The EPA has concends because manganese is a neurotoxin...
MMT is a gasoline octane enhancer produced by the Ethyl Corporation. MMT is allowed in U.S. gasoline at a level equivalent to 1/32 grams per gallon manganese (gpg Mn).
In its decision on the use of MMT in the U.S., the Agency determined that MMT added at 1/32 gpg MN will not cause or contribute to regulated emissions failures of vehicles. Some have expressed concerns that the use of MMT may harm on-board diagnostic equipment (OBD) which monitors the performance of emissions control devices in the vehicle. As of this time, the Agency believes the data collected is inconclusive with regard to OBD.
Manganese is a neurotoxin and can cause irreversible neurological disease at high levels of inhalation. However, ingested manganese is a required element of the diet at very low levels. There is a concern that the use of manganese additives in gasoline could increase inhalation manganese exposures.
After completing a risk evaluation in 1994 on the use of MMT in gasoline, EPA was unable, based on the available data, to determine if these is a risk to the public health from exposure to emissions of MMT gasoline. The Agency stated "Although it is not possible based on the present information to conclude whether specific adverse health effects will be associated with manganese exposures in the vicinity of or exceeding the [estimated safe level over a lifetime of exposure], neither is it possible to conclude that adverse health effects will not be associated with such exposures." This assessment was based upon the level of MMT allowed in U.S. gasoline.
More specifically, modeling indicates that, as a result of MMT use in unleaded gasoline, certain portions of the population may be exposed to levels in the same range as the Reference Concentration (RfC or safe level for a lifetime exposure with an order of magnitude uncertainty). Because the expected exposure is not much higher or much lower than the RfC, a definitive conclusion about risk is impossible to reach. Long-term animal testing and exposure research are needed to more accurately define the risk.
Under Clean Air Act authority to require testing of motor fuels and additives, EPA has required the Ethyl Corporation to perform testing to help fill in data gaps and potentially provide information that would result in a more definitive risk evaluation. After submission of this additional information late in 2004, the Agency will study the results. The Agency may then be able to refine its risk evaluation or may ask for further testing based upon the results of the testing now being performed.
With funding from Ethyl Corporation, Research Triangle Institute (RTI) has also completed a study of manganese exposures in Toronto, Canada where MMT is used. The Agency is evaluating this study to determine what impact it might have on any evaluation of risk associated with use of the additive.
