wifey says fill it up with 87
01-19-2011, 10:35 AM
#61
Audi Forum - Posts like an A5
Join Date: Oct 2010
Location: Republic of B.C.!
Posts: 382
Re: wifey says fill it up with 87
Originally Posted by Jim Nash Cars.com
High-octane, or premium, gas doesn't boost a car's performance. In fact, you can increase the octane of gasoline by mixing in ethanol and actually decrease the potential energy in the blended fuel. Premium helps prevent the knocking and pinging you hear when fuel ignites as it's compressed in an engine cylinder before the spark plug fires. Knocking and pinging can damage your engine. Left unattended, it can burn a hole through a piston head.
Octane ratings can be increased using additives including methyl tertiary-butyl ether, ethyl-tertiary butyl ether and toluene. Until the 1970s, tetra-ethyl lead -- as in "leaded gas" -- was used to boost octane ratings. Leaded gas today is a pariah fuel in most developed nations because of its links to the damaging lead levels it has contributed to human bloodstreams. Engines with a high compression ratio -- typically sport and luxury models -- are more prone to knocking, which is why manufacturers of those vehicles recommend or require you use high-octane gas.
Even those instances are rare in new vehicles. Most late-model autos have microphones that listen for the distinctive sound of knocking and software that reacts to that sound by retarding ignition timing. That eliminates the knocking at the expense of some performance because the piston is farther down in the cylinder when ignition occurs. Gas delivers more power when it burns in a smaller space.
Want to see how the knock sensor affects engine operation -- or to test that it's working? Find the sensor on the manifold and tap a wrench on the engine block nearby while the engine idles. You'll see the timing change briefly.
Bottom line: If your owner's manual says your warranty requires premium gas, by all means use it. If it says premium is recommended, follow your budget.
Octane ratings can be increased using additives including methyl tertiary-butyl ether, ethyl-tertiary butyl ether and toluene. Until the 1970s, tetra-ethyl lead -- as in "leaded gas" -- was used to boost octane ratings. Leaded gas today is a pariah fuel in most developed nations because of its links to the damaging lead levels it has contributed to human bloodstreams. Engines with a high compression ratio -- typically sport and luxury models -- are more prone to knocking, which is why manufacturers of those vehicles recommend or require you use high-octane gas.
Even those instances are rare in new vehicles. Most late-model autos have microphones that listen for the distinctive sound of knocking and software that reacts to that sound by retarding ignition timing. That eliminates the knocking at the expense of some performance because the piston is farther down in the cylinder when ignition occurs. Gas delivers more power when it burns in a smaller space.
Want to see how the knock sensor affects engine operation -- or to test that it's working? Find the sensor on the manifold and tap a wrench on the engine block nearby while the engine idles. You'll see the timing change briefly.
Bottom line: If your owner's manual says your warranty requires premium gas, by all means use it. If it says premium is recommended, follow your budget.
SOURCE
01-19-2011, 12:30 PM
#64
Re: wifey says fill it up with 87
"Lower octane gas is going to run hotter, and potentially damage your rings. (yes I've replaced rings/engines on cars because people have done this before)
If you read the labels on the octane booster
bottle, many of them claim to increase octane and "power" by cleaning your fuel injectors.
This is not the same.
Octane rating gives a guide toward resistance to detonation. Any ability to detect knock and adjust engine timing is a condition where something bad has been detected and the electronics attempt to compensate while a bad condition exists. (ignition at the wrong time!)"
"Your engine is high compression and 91 octane is better at resisting PRE-ignition under higher compression and temperature than an 89 octane is. So that is why you should always use Manufacture recommended octanes MINIMUM.
If you have access to 93, that's what you should be using all the time.
If you have to use 89, then don't rev it up as high, be lighter on the throttle, this will lessen the chance that you will require the capabilities of 91 octane."
This can also cause carbon deposits within the engine
The quoted posts are from a quick google search and other Audi Members, the first post is from a mechanic.
I will do some more research to bring this thread to stop
My standpoint on this is that,
Yes 91 octane is way better for your fuel economy, the engine and the life of the car, as lower octane fuel burns hotter and can cause damage over time. This is especially true for turbo engines and high HP engines.
Using 87 all the time is at the risk of the user right, If you drive it like its stolen high rev it etc. do yourself a favor and fill up with 91 or higher, so your car does not have to compensate for the losses during those periods.
Hope that helps clear up my stand point on this, however the whole morality issue from the OP is a whole other can of worms
If you read the labels on the octane booster
bottle, many of them claim to increase octane and "power" by cleaning your fuel injectors.
This is not the same.
Octane rating gives a guide toward resistance to detonation. Any ability to detect knock and adjust engine timing is a condition where something bad has been detected and the electronics attempt to compensate while a bad condition exists. (ignition at the wrong time!)"
"Your engine is high compression and 91 octane is better at resisting PRE-ignition under higher compression and temperature than an 89 octane is. So that is why you should always use Manufacture recommended octanes MINIMUM.
If you have access to 93, that's what you should be using all the time.
If you have to use 89, then don't rev it up as high, be lighter on the throttle, this will lessen the chance that you will require the capabilities of 91 octane."
This can also cause carbon deposits within the engine
The quoted posts are from a quick google search and other Audi Members, the first post is from a mechanic.
I will do some more research to bring this thread to stop
My standpoint on this is that,
Yes 91 octane is way better for your fuel economy, the engine and the life of the car, as lower octane fuel burns hotter and can cause damage over time. This is especially true for turbo engines and high HP engines.
Using 87 all the time is at the risk of the user right, If you drive it like its stolen high rev it etc. do yourself a favor and fill up with 91 or higher, so your car does not have to compensate for the losses during those periods.
Hope that helps clear up my stand point on this, however the whole morality issue from the OP is a whole other can of worms
01-19-2011, 12:36 PM
#65
Audi Forum - Posts like an A1
Join Date: Dec 2010
Posts: 8
Re: wifey says fill it up with 87
Hi Everyone, My name is Lou and I own All About Imports in Mississauga. Mike H pointed me to this thread and asked if I would add my two cents worth. I am a Honda/Acura factory trained tech with twenty years experience and Terry is our Audi Tech with 25 years experience. Terry is busy right now so I thought I would participate.. For the most part Terry and I are in agreement on the following. I have read most comments (in this thread) and while there is a lot of relevant good information... some info might be dated.
I'll relate my Acura insight as the differences in fuel relate equally to Audi & Acura's.. etc. (the Acura/Honda products that use premium anyways)
First off, both Terry and I in our 45 years of combined dealer and independent repair history have never repaired an engine that had anything to do with fuel/octane related detonation damage.. and trust me we have done a lot of engine work.
Contemporary German or Japanese auto's (vehicles that are approx 2008 and newer) have onboard management systems that are dramatically more complex than vehicles from the early 2000's.. Computing speeds of these cars can be compared to that of a PC running in the P4 range, stuff from the late 90's and early 00's can be compared to P1's and anything from the mid 90's is similar to the commodore 64.. (I still fondy remember my commodore 64)
Computing/processing speed is relevant to this discussion because of knock sensor. Nowadays the computer can sense knock almost before it happens which goes along way reducing pre-detonation.
Octane level (simplified) is the resistance to pre detonation. Manufacturers can push your timing further into the "danger" zone when you are using the correct grade of fuel. When you do not use the proper grade of fuel the computer simply cannot advance the timing to where it wants it to be in response to your throttle position. Therefore the engine simply will not respond as well as it could potentially. That being said, vehicles that use premium from earlier generations are not equally capable of reducing timing as quickly and the potential is there to do harm.. (it is rare though) most engines are made to absorb a certain amount of pre detonation without causing any engine damage. The driver would have to be grossly negligent or purposely trying to make it ping.
By the way, taking a wrench and taping it beside the knock sensor would only affect the idle on a much older car.
Regular fuel is what I call "dirty" fuel. Extended use of regular will cause carbon build that has lots of related repairs. This is another topic though.
I hope this helps
Lou
All About Imports
I'll relate my Acura insight as the differences in fuel relate equally to Audi & Acura's.. etc. (the Acura/Honda products that use premium anyways)
First off, both Terry and I in our 45 years of combined dealer and independent repair history have never repaired an engine that had anything to do with fuel/octane related detonation damage.. and trust me we have done a lot of engine work.
Contemporary German or Japanese auto's (vehicles that are approx 2008 and newer) have onboard management systems that are dramatically more complex than vehicles from the early 2000's.. Computing speeds of these cars can be compared to that of a PC running in the P4 range, stuff from the late 90's and early 00's can be compared to P1's and anything from the mid 90's is similar to the commodore 64.. (I still fondy remember my commodore 64)
Computing/processing speed is relevant to this discussion because of knock sensor. Nowadays the computer can sense knock almost before it happens which goes along way reducing pre-detonation. Octane level (simplified) is the resistance to pre detonation. Manufacturers can push your timing further into the "danger" zone when you are using the correct grade of fuel. When you do not use the proper grade of fuel the computer simply cannot advance the timing to where it wants it to be in response to your throttle position. Therefore the engine simply will not respond as well as it could potentially. That being said, vehicles that use premium from earlier generations are not equally capable of reducing timing as quickly and the potential is there to do harm.. (it is rare though) most engines are made to absorb a certain amount of pre detonation without causing any engine damage. The driver would have to be grossly negligent or purposely trying to make it ping.
By the way, taking a wrench and taping it beside the knock sensor would only affect the idle on a much older car.
Regular fuel is what I call "dirty" fuel. Extended use of regular will cause carbon build that has lots of related repairs. This is another topic though.
I hope this helps
Lou
All About Imports
01-19-2011, 12:45 PM
#66
Audi Forum - Posts like an A1
Join Date: Dec 2010
Posts: 8
Re: wifey says fill it up with 87
One more thing I forgot to mention... If your newer Audi develops any kind of engine noise while under warranty you can bet that they (dealer) will be looking at the knock count. The computer records how many times it detects knock... So lets translate this into the real world...
Manufactures are looking for any reason to decline your warranty claim... Please don't give them one. Even if your engine throws a rod due to your stoplight to stoplight driving style, they will be looking...
My advice is to use the recommended oil and fuel while under warranty, after that its up to you.
Lou
Manufactures are looking for any reason to decline your warranty claim... Please don't give them one. Even if your engine throws a rod due to your stoplight to stoplight driving style, they will be looking...
My advice is to use the recommended oil and fuel while under warranty, after that its up to you.
Lou
01-19-2011, 12:58 PM
#68
Audi Forum - Posts like an A4
Join Date: May 2009
Location: Canada
Posts: 193
Re: wifey says fill it up with 87
Thank you very much, Lou. Your input is appreciated.
I have asked my lawyer about the wording in the manual: because it is stated in the owner's manual, the dealerships can not refuse warranty repairs because of the use of 87 gas. They can try, but... they will never have a case in court.
1Move, I really appreciate your concern about proper use of our cars. Sincerely. On this, I am with you entirely.
Many thanks to all contributors to this thread. This is an amazing forum.
I am done here.
I have asked my lawyer about the wording in the manual: because it is stated in the owner's manual, the dealerships can not refuse warranty repairs because of the use of 87 gas. They can try, but... they will never have a case in court.
1Move, I really appreciate your concern about proper use of our cars. Sincerely. On this, I am with you entirely.
Many thanks to all contributors to this thread. This is an amazing forum.
I am done here.
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