Mid-grade (89 oct) gasoline
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SFCP, looks like the lumina has a knock sensor, V6 3.1 Liter FI - 189 CID VIN M O.H.V. Part No.KS8. the dodge caravan also has a knock sensor, V6 3.3 Liter FI - 201 CID VIN R, V6 3.3 Liter FI - 201 CID VIN G EGM, part#KS70, the part numbers are for mostly for reference as different store carry different brands with different part numbers
Only if the ECM has the parameters and programing to make adjustments(and of course if you have electronicly controled ignition (distributorless). Normally, when equiped with knock sensors the ECM will retard the timing when knock is detected. The abilityt to advance the timing when higher octane is used is sometimes restricted. So many engines are not able to advance the timing to take advantage of higher Octane. The key indicator that the engine has this ability is in the owners manual. If the car recomends regular unleaded but says best performance can be achived by using premium and the published horsepower tests are donw with higher than 87 octane fuel this indicates that there is improvement from octane. If there is no mention of using higher octane for improved performance then it is likely that the manufacturere did not supply the elctronics with the ability to make large advances in timing.
Some cars Require high octane due to there high compression ratios or forced induction. They will definately lose performance and knock if lower octane is used because the knocking may go beyond the ECM's ability to retard the timing.
So for your engines I don't know. I had to research alot to understand my engiens abilities.
Some cars Require high octane due to there high compression ratios or forced induction. They will definately lose performance and knock if lower octane is used because the knocking may go beyond the ECM's ability to retard the timing.
So for your engines I don't know. I had to research alot to understand my engiens abilities.
while data logging my car on different grades the highest grade did allow for more advanced timing but its not infinite if i dump in some octane boost its not gonna keep advancing the timing up to some ungodly number it pretty much stops advancing when you reach top grade 92 or 93 but with the programmer im able to advance the timing and fuel curve over factory spec even running 92
and just to add there are differences in fuel from different vendors, when i filled up at a sunoco once i had to back the timing of some because i got knock but once i filled up again with shell after i let it go down till the gas light came on i was able to step the timing back up so i only use shell 92 or 93
Which leads to my next question..My 2000 Dodge Gr Caravan is a flex-fuel capable veh. I pretty much stick with 87 octane: however, I know that E-85 is upwwards of 100+ octane, so the fuel system has been designed to handle this. The manual does state that rough performance may be noted at times due to the octane level, so if this is true of my van, is there any advancement in timing when using E-85?
ignition timing is pretty much controlled by ECU these days so unless there's a dramatic call for reprogramming your ECU to accommodate specific fuel type that you use, otherwise, don't play scientist with your ignition timing or you may suffer from severe engine damage due to detonation.
Yes, the old trick calls for the manipulation of ignition timing (rotation of distributor or vaccuum controller advance profile, governor spring tension, etc.)to take advantage of the fuel type used and most obvious signs of performance improvements typically comes from advancing the ignition timing a bit (not too much to the point of causing/inducing detonation).All these factors are pretty much determined by the specific engine designs, compression ratio, combustion chamber designs, amount of combustion chamber deposits and carbon deposits accumulated, specific operational conditions, etc. and no 2 engine would behave the same if you try to mimic the same amount of ignition timing advancements (some engine designs are less tolerant to high degrees of ignition timing advancement).In other words: some engine are more capable of accepting a high degree of ignition timing advance w/o experiencing detonation while others may not.
Computers are very smart these days in a sense that it is capable of auto-adjust/fine tune the ignition timing for a specific engine design to take advantage of the fuel type used, and thus there's no need to play scientist/#@$%!/engineer in hopes of squeezing extra hp out of a said engine.
Also: despite the higher octane achieved by adding additional ethanol into the gasoline mix, it also actually alters the flame propagation behaviour/speed somewhat, so that may be the cause of some driveability issues in some states RE: E85.
Yes, the old trick calls for the manipulation of ignition timing (rotation of distributor or vaccuum controller advance profile, governor spring tension, etc.)to take advantage of the fuel type used and most obvious signs of performance improvements typically comes from advancing the ignition timing a bit (not too much to the point of causing/inducing detonation).All these factors are pretty much determined by the specific engine designs, compression ratio, combustion chamber designs, amount of combustion chamber deposits and carbon deposits accumulated, specific operational conditions, etc. and no 2 engine would behave the same if you try to mimic the same amount of ignition timing advancements (some engine designs are less tolerant to high degrees of ignition timing advancement).In other words: some engine are more capable of accepting a high degree of ignition timing advance w/o experiencing detonation while others may not.
Computers are very smart these days in a sense that it is capable of auto-adjust/fine tune the ignition timing for a specific engine design to take advantage of the fuel type used, and thus there's no need to play scientist/#@$%!/engineer in hopes of squeezing extra hp out of a said engine.
Also: despite the higher octane achieved by adding additional ethanol into the gasoline mix, it also actually alters the flame propagation behaviour/speed somewhat, so that may be the cause of some driveability issues in some states RE: E85.
There are parameters to the stock ECU controlled ignition tuning, of course at that point if you still want to try to gain more youcan try changing the fuel mapping.. This is going in when warranty is out for me(along with more goodies on this site MAF Sensor calibrator
you need to be carefull playing with maf functions alone as it can cause you to run to lean or to rich very easy. if i was only getting the calibrator id also get a air/fuel ratio gauge. i have an aftermarket 90mm maf to take the place of the stock 65mm but i also tuned it to run almost stock transfer function but the larger size maf and tb flow alot more air
I think the law says that all grades must have a certain minimum amount of detergents and if I am not mistaken the companies are not supposed to make claims of better cleaning with premium gas.....or something like that, even if they have more detergents. Don't know how that allows Shell to be claiming their premium will clean your engine? A long time ago the lower octane fuels did not have any detergents and with fuel injection this caused problems and they (auto makers and/or EPA) came up with requiring detergents in all grades.
I never use anything but shell regular 87 grade (96 LX450 and 87 4Runner). my back-up is chevron regular.
I have been using shell regular 87 because it's on the list and I happen to get the best gas mileage from the shell fuels, even their diesel.
http://www.caranddriver.com/article.asp?section_id=27&article_id=9752&page_number=1
http://www.toptiergas.com/index.html
http://www.toptiergas.com/retailers.html
I have been using shell regular 87 because it's on the list and I happen to get the best gas mileage from the shell fuels, even their diesel.
http://www.caranddriver.com/article.asp?section_id=27&article_id=9752&page_number=1
http://www.toptiergas.com/index.html
http://www.toptiergas.com/retailers.html
I run diesel instead of regular. I get a lot of smoke from the tailpipe, but someone on the internet told me it's better power. j/k
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