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Old 11-23-2011, 01:27 PM
seemyad's Avatar
seemyad seemyad is offline
BMW ****ie
Location: Seattle WA
Join Date: Jul 2011
Posts: 1,320
Mein Auto: 530i Sport Package
Originally Posted by jarhed1964 View Post

Getting the head cleaned/cut. Some warpage going on there and some coolant leaks. Waiting to hear if he found any cracks. Damn thing was a bear to pull off with all the crap attached to it.

Anyway, look at the scale and crap on top of these pistons. Shop guy does engines for the BMW Stealer in Charlotte and told me to stop burning 87 octane because it puts huge thick carbon deposits all over the place.

This post goes toward validating the argument AGAINST using low octane fuel vs recommended high octane. I always use 9X grade and some tried to argue in favor of 8X. Lower octane gas is less stable than high octane (under pressure). Pressure exerted on 8X by the pistons may prematurely ignite the 8X crap-gas (aka knocking). Our engines correct for the premature ignitions by changing the timing (prevents knocking). yet people STILL try to argue in favor of using crap-gas based on science that has ZERO to do with the reason BMWs require high octane fuel. BMWs have a high compression ratio as with most "performance" cars. Higher the compression the more likely 8X will ignite prematurely which is then corrected by throwing off the engine timing to compensate.

Crap-gas misfired timing WILL impact your fuel-air mixture. Which, in turn, CAN lead to more carbon buildup over time. As for the rest of the unrelated information, nothing promotes using 8X octane beyond people trying to drive an executive level car on a shoe string budget.

THANK YOU for this post as a picture says 1000 words. Not just because it validates my stand, more so because it is very educational for us all.


Last edited by seemyad; 11-23-2011 at 01:44 PM.
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