Premium to Unleaded what are the effects.
06-02-2008, 02:58 PM
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S430 Sold :(
Premium to Unleaded what are the effects.
What would be the adverse affects of switching from premium to unleaded? All of you are well aware of the gas prices. Is there any direct effets to running unleaded?
06-02-2008, 04:03 PM
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Most cars have engines that can retard the ignition from a lesser grade gasoline. Whereas in the past in could cause engine knock. The worse thing that would happen would be a slight loss in power and decrease in MPG. Unless you run the car hard you won't notice a thing.
06-02-2008, 04:40 PM
#3
Most cars have engines that can retard the ignition from a lesser grade gasoline. Whereas in the past in could cause engine knock. The worse thing that would happen would be a slight loss in power and decrease in MPG. Unless you run the car hard you won't notice a thing.
Stick to premium
06-02-2008, 05:18 PM
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There is also the strong possiblity of long term damage; clogged cats, shorter life of some sensors, valve damage, piston damage and so on. this would be over the long term. The engineers at MB designed the engine to run on 91 octane. Do you know more about that then them??
06-02-2008, 05:52 PM
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But why would any car get less mpg on a lower octane gas? In fact lower octane has more energy/BTU than higher octane gas. Octane is not gasoline but is used only to prevent gasoline from self-detonating due to higher compression. THe computer will continually adjust so that the air/fuel mixture is as closed to perfect (14.7:1) as possible. However you will lose some top end power.
06-02-2008, 06:17 PM
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There is also the strong possiblity of long term damage; clogged cats, shorter life of some sensors, valve damage, piston damage and so on. this would be over the long term. The engineers at MB designed the engine to run on 91 octane. Do you know more about that then them??
Engineering does not manage the Octane rating of cars The EPA does in the US. If that were the case All of the European cars and cars of many different countries would suffer that horrible fate you listed above because the octane measurement is different in many countries than it is here.. Have you ever been to France or Germany, or Central America?? How do explain the way they all sell Petrol? Octane ratings are all over the place....
but to add a correction to your statement,
LEADED gas causes long term problems such as premature wear on CATs.
detonation, ( knocking) which could wear internal engine components over a LONG period if its Excessive...
Notice the common keywords here are long term.... WHo know what long term really is....Hmmm.
Changing from 91 to 89 octane just effects the cars performance, and wastes more fuel for a car that is tuned for premium..
Originally Posted by vraa
And the lower mpg, in the end, makes it less cost efficient to use the lower octane gas
Stick to premium
Stick to premium
I know its the tuning... but getting worse Mph in an efforts to save some cents per gallon is very counterproductive...
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06-02-2008, 06:53 PM
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Who told you that ??.. That is the biggest myth EVER!! Give me a break.
Engineering does not manage the Octane rating of cars The EPA does in the US. If that were the case All of the European cars and cars of many different countries would suffer that horrible fate you listed above because the octane measurement is different in many countries than it is here.. Have you ever been to France or Germany, or Central America?? How do explain the way they all sell Petrol? Octane ratings are all over the place....
but to add a correction to your statement,
LEADED gas causes long term problems such as premature wear on CATs.
detonation, ( knocking) which could wear internal engine components over a LONG period if its Excessive...
Notice the common keywords here are long term.... WHo know what long term really is....Hmmm.
Changing from 91 to 89 octane just effects the cars performance, and wastes more fuel for a car that is tuned for premium..
My car runs like Crap and burns more gas if I don't use premium...
I know its the tuning... but getting worse Mph in an efforts to save some cents per gallon is very counterproductive...
Engineering does not manage the Octane rating of cars The EPA does in the US. If that were the case All of the European cars and cars of many different countries would suffer that horrible fate you listed above because the octane measurement is different in many countries than it is here.. Have you ever been to France or Germany, or Central America?? How do explain the way they all sell Petrol? Octane ratings are all over the place....
but to add a correction to your statement,
LEADED gas causes long term problems such as premature wear on CATs.
detonation, ( knocking) which could wear internal engine components over a LONG period if its Excessive...
Notice the common keywords here are long term.... WHo know what long term really is....Hmmm.
Changing from 91 to 89 octane just effects the cars performance, and wastes more fuel for a car that is tuned for premium..
My car runs like Crap and burns more gas if I don't use premium...
I know its the tuning... but getting worse Mph in an efforts to save some cents per gallon is very counterproductive...
06-02-2008, 07:47 PM
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Engineers in design of an engine specify the required octane to deliver the specified performance. It is a factor of the compression ratio of the engine. If a lower octane is used it will burn longer in the cylinder and produce more carbon in the exhaust. It will also produce a hotter exhaust. These factors will eventually do some damage to the engine. If it were not for the knock sensor the damage would occurr faster. With a lower octane than specified there is power loss, not only at the top end but thru out the power range of the engine. In some non automotive applications such as aircraft and marine where the engines are working harder all the time there are specific throttle and MAP limitations on the engines when using a lower than specified octane fuel. With aircraft (air cooled) engines higher climb speeds must also be used to keep the cylinder heads within the temp range that is safe. Octane ratings were around and a consideration in engine design long before the EPA was even thought about. There were even dual range aircraft fuel such as 115/145 octane where certain power settings were to be used only for a specified time and/or with water injection to prevent detonation.
You wouldn't put 91 Octane in a 155/145 engine.. IF you could then using 89 instead wouldn't make that much of a difference.. True or not?
That was the whole point in question..
There is no way I am going to believe for a second that using 89 instead of 91 octane will cause the damage you stated in a normal cars lifetime..
But it's not a argument from me.. i won;t do it anyway.. I don;t care what gas prices go to... If i can't afford the right gas, i'll just park the thing..LOL..
I'd rather do that than have to drive it underperforming....
06-02-2008, 08:52 PM
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Mnn I know about airplanes, I am A licensed A&P... But this is a bit overboard to compare that to a car that has no where near the stress and usage of a commercial aircraft engine??
You wouldn't put 91 Octane in a 155/145 engine.. IF you could then using 89 instead wouldn't make that much of a difference.. True or not?
That was the whole point in question..
There is no way I am going to believe for a second that using 89 instead of 91 octane will cause the damage you stated in a normal cars lifetime..
But it's not a argument from me.. i won;t do it anyway.. I don;t care what gas prices go to... If i can't afford the right gas, i'll just park the thing..LOL..
I'd rather do that than have to drive it underperforming....
You wouldn't put 91 Octane in a 155/145 engine.. IF you could then using 89 instead wouldn't make that much of a difference.. True or not?
That was the whole point in question..
There is no way I am going to believe for a second that using 89 instead of 91 octane will cause the damage you stated in a normal cars lifetime..
But it's not a argument from me.. i won;t do it anyway.. I don;t care what gas prices go to... If i can't afford the right gas, i'll just park the thing..LOL..
I'd rather do that than have to drive it underperforming....
No I would not use any automotive gas in an aircraft unless it was one of the few that was powered with a low powered engine that had a 337 allowing its use. As far as using 89 octane in a 115/145 engins such as a 3350 or 4360, the engine would most likely fail during its first take off. As far as the long term damage effect of using regular instead of 91 in an MB. I am willing to bet that if you tore the engine down at 100000 miles you would see excessive wear and signs of heat damage. If you did this for the life of an engine you would most likely shorten its life by 25%. No I do not do it either the actual cost difference is insignificant. The performance and longevity that I paid for by buying one of the MB vehicles would not be there even though I buy new and only keep the vehicle for 4 to 5 years.
06-02-2008, 09:45 PM
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Don't do it. If the car says 91 (R+M)/2 minimum (equivalent to RON 95, as it is known in Europe and most of the world), it means that is the minimum requirement.
Last edited by Untertürkheim; 06-02-2008 at 11:41 PM.
06-02-2008, 10:33 PM
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Good to know that you also have an A&P. I also have an ATP, had an IA and have over 30 years experience with business aircraft and was with an airline for 30 years as a captain with USN flight experience also.
No I would not use any automotive gas in an aircraft unless it was one of the few that was powered with a low powered engine that had a 337 allowing its use. As far as using 89 octane in a 115/145 engins such as a 3350 or 4360, the engine would most likely fail during its first take off. As far as the long term damage effect of using regular instead of 91 in an MB. I am willing to bet that if you tore the engine down at 100000 miles you would see excessive wear and signs of heat damage. If you did this for the life of an engine you would most likely shorten its life by 25%. No I do not do it either the actual cost difference is insignificant. The performance and longevity that I paid for by buying one of the MB vehicles would not be there even though I buy new and only keep the vehicle for 4 to 5 years.
No I would not use any automotive gas in an aircraft unless it was one of the few that was powered with a low powered engine that had a 337 allowing its use. As far as using 89 octane in a 115/145 engins such as a 3350 or 4360, the engine would most likely fail during its first take off. As far as the long term damage effect of using regular instead of 91 in an MB. I am willing to bet that if you tore the engine down at 100000 miles you would see excessive wear and signs of heat damage. If you did this for the life of an engine you would most likely shorten its life by 25%. No I do not do it either the actual cost difference is insignificant. The performance and longevity that I paid for by buying one of the MB vehicles would not be there even though I buy new and only keep the vehicle for 4 to 5 years.
Wow that's cool!!
Are you still in the industry or retired?
I've been out of that business since '93'. After school, I did military for 4 years and then Defense contracting for another 8.. That was enough for me..LOL on to bigger ( smaller ) better things... Never did too much commercial, only part time for a short while...
I've been in the Tech industry for the past 10 years or so and have had my own consulting business the past 4. Needless to say, between businesses, I have very little time or energy for going too deep into any engines these days.. That's why I like these cars so much.. most of the issues are small, and structural.. hardly ever have to deal with the Engine or tranny except regular maintenance stuff.. Kinda nice..( hope I didn't just jinx myself...)
If I knew why my car was drinking washer fluid, I'd never open my hood unless I was cleaning the engine or doing my 10K service. NOW That's a luxury in itself..
06-03-2008, 02:36 PM
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the cost is insignificant
it is simply a tendency to buy the cheap stuff cause it is right there and you have to make a choice.the cost of a 20 gallons at $4.39 versus $469 is a whopping $6.it isnt worth even considering.eat less fast food and burn more premium.whats with all the A&P's.me too.rotary wings,more parts to sling.
06-04-2008, 04:19 AM
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From the manual:
To maintain engine durability and performance, use only premium unleaded gasoline. If premium unleaded is not available and low octane gasoline is used, follow these precautions:
• Partially fill the fuel tank with unleaded regular gasoline and fill up with premium unleaded as soon as possible.
• Avoid full throttle driving and abrupt acceleration.
• Do not exceed engine speeds of 2000 rpm if the vehicle has a light load - such as two occupants and no luggage.
• Do not exceed 2/3 of maximum accelerator pedal position if the vehicle is fully loaded or operating in mountaious terrain.
Octane rating is not mandated by the EPA. Where did that myth come from?
To maintain engine durability and performance, use only premium unleaded gasoline. If premium unleaded is not available and low octane gasoline is used, follow these precautions:
• Partially fill the fuel tank with unleaded regular gasoline and fill up with premium unleaded as soon as possible.
• Avoid full throttle driving and abrupt acceleration.
• Do not exceed engine speeds of 2000 rpm if the vehicle has a light load - such as two occupants and no luggage.
• Do not exceed 2/3 of maximum accelerator pedal position if the vehicle is fully loaded or operating in mountaious terrain.
Octane rating is not mandated by the EPA. Where did that myth come from?
06-04-2008, 06:17 PM
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Wow that's cool!!
Are you still in the industry or retired?
I've been out of that business since '93'. After school, I did military for 4 years and then Defense contracting for another 8.. That was enough for me..LOL on to bigger ( smaller ) better things... Never did too much commercial, only part time for a short while...
I've been in the Tech industry for the past 10 years or so and have had my own consulting business the past 4. Needless to say, between businesses, I have very little time or energy for going too deep into any engines these days.. That's why I like these cars so much.. most of the issues are small, and structural.. hardly ever have to deal with the Engine or tranny except regular maintenance stuff.. Kinda nice..( hope I didn't just jinx myself...)
If I knew why my car was drinking washer fluid, I'd never open my hood unless I was cleaning the engine or doing my 10K service. NOW That's a luxury in itself..
Are you still in the industry or retired?
I've been out of that business since '93'. After school, I did military for 4 years and then Defense contracting for another 8.. That was enough for me..LOL on to bigger ( smaller ) better things... Never did too much commercial, only part time for a short while...
I've been in the Tech industry for the past 10 years or so and have had my own consulting business the past 4. Needless to say, between businesses, I have very little time or energy for going too deep into any engines these days.. That's why I like these cars so much.. most of the issues are small, and structural.. hardly ever have to deal with the Engine or tranny except regular maintenance stuff.. Kinda nice..( hope I didn't just jinx myself...)
If I knew why my car was drinking washer fluid, I'd never open my hood unless I was cleaning the engine or doing my 10K service. NOW That's a luxury in itself..
06-04-2008, 08:29 PM
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some time and actually troubleshoot this problem. I will apply 3 to 4 psi or air to my reservoir and try to find this whodini leak.. ITs driving me crazy..LOL
I'm doing my 10K service soon so I'll have a closer look at that time..
06-09-2008, 12:08 AM
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check the cap
Wow that's cool!!
Are you still in the industry or retired?
I've been out of that business since '93'. After school, I did military for 4 years and then Defense contracting for another 8.. That was enough for me..LOL on to bigger ( smaller ) better things... Never did too much commercial, only part time for a short while...
I've been in the Tech industry for the past 10 years or so and have had my own consulting business the past 4. Needless to say, between businesses, I have very little time or energy for going too deep into any engines these days.. That's why I like these cars so much.. most of the issues are small, and structural.. hardly ever have to deal with the Engine or tranny except regular maintenance stuff.. Kinda nice..( hope I didn't just jinx myself...)
If I knew why my car was drinking washer fluid, I'd never open my hood unless I was cleaning the engine or doing my 10K service. NOW That's a luxury in itself..
Are you still in the industry or retired?
I've been out of that business since '93'. After school, I did military for 4 years and then Defense contracting for another 8.. That was enough for me..LOL on to bigger ( smaller ) better things... Never did too much commercial, only part time for a short while...
I've been in the Tech industry for the past 10 years or so and have had my own consulting business the past 4. Needless to say, between businesses, I have very little time or energy for going too deep into any engines these days.. That's why I like these cars so much.. most of the issues are small, and structural.. hardly ever have to deal with the Engine or tranny except regular maintenance stuff.. Kinda nice..( hope I didn't just jinx myself...)
If I knew why my car was drinking washer fluid, I'd never open my hood unless I was cleaning the engine or doing my 10K service. NOW That's a luxury in itself..
06-09-2008, 06:08 PM
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I have had several guys come in for tuning (E55) and they were running in 87 and 89 octane fuel and the engines both knocked under acceleration. The cars also did not respond well to our tuning until they started running the proper fuel. But the cars came back to life after a couple of tanks of the good stuff!
