Gas Octane Rating for E12's?
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canada karl
- Posts: 1065
- Joined: Tue Jan 06, 2009 3:50 pm
Gas Octane Rating for E12's?
I've been running my 76 530i on 90 octane gas because I figured that was what the M30 motor was designed for. Would running on gas with a lower Octane reading cause problems with engine performance? Reduced power?Thinking of going on a 1000 mile trip and wondering if it's worth it to run the lower Octane to save a few bucks? Gas up here is pushing $6 a gallon in some places. Also the 90 Octane up here has no Ethanol but the 87 has 10%. Is the Ethanol going to bugger up the rubber fuel lines? Any thoughts
1976 530i. BMW 59 Triumph TR3A(rolling resto). 67 Triumph TR4A(salvageable). 86 900S Winter car
Right or wrong I've used the lowest, cheapest octane (87 ?) gas for twenty years in my 528i's. No knocks, pings or odd timing, using the WR9-DS Bosch plugs. They've always looked good.
For what it's worth I use high octane in the 633, 635. Haven't been paying attention to what the greenies are pouring into the mix to assure freshness. From racing experience small amounts of fuel additive (ethanol) don't usually eat the aluminum components at any rates we'd notice.
Awaiting more learned responses.
For what it's worth I use high octane in the 633, 635. Haven't been paying attention to what the greenies are pouring into the mix to assure freshness. From racing experience small amounts of fuel additive (ethanol) don't usually eat the aluminum components at any rates we'd notice.
Awaiting more learned responses.
I can't disagree, or loudly proclaim any scientific last word.
First, 98RON, who's Ron ? More meaningless acronyms. Not that it doesn't probably stand for something. Somewhere.
I just don't put much faith the stickers on my corner pumps know who Ron is either. We got ethanol blends, maybe some root beer from the last load.
Octane has to do with the fuels willingness to ignite. Low (89) is more willing than high (92). The higher the compression in the engine, the higher the octane rating necessary to resist the mixture igniting too soon, while the piston is still on the up stroke.
Low octane (cheap gas) is too willing to explode early. When it ignites with the piston still rotating up, connecting rod on the crank shaft, the poor piston assembly is in a fight between its construction and the explosion meant to be driving it down in the cylinder, rotating the crank shaft, etc.
The fight is called pre-ignition, pinging or rod knock. Nucka, nucka, nucka especially from a low speed in say third gear. If you had a cylinder head temp gauge you'd see it go higher.
You can adjust the timing a dab or move up to the next higher octane on your next pit stop.
If there's a point to this it's just to know the right octane to buy is the lowest one that doesn't make knocking noises. The engine has no idea from higher octane, or flavors, or freshness tasty.
Read the plugs. Grey brown with a few deposits is good. Glazed, very white core, few deposits needs Bosch WR9 DS, correct timing, probably higher octane.
First, 98RON, who's Ron ? More meaningless acronyms. Not that it doesn't probably stand for something. Somewhere.
I just don't put much faith the stickers on my corner pumps know who Ron is either. We got ethanol blends, maybe some root beer from the last load.
Octane has to do with the fuels willingness to ignite. Low (89) is more willing than high (92). The higher the compression in the engine, the higher the octane rating necessary to resist the mixture igniting too soon, while the piston is still on the up stroke.
Low octane (cheap gas) is too willing to explode early. When it ignites with the piston still rotating up, connecting rod on the crank shaft, the poor piston assembly is in a fight between its construction and the explosion meant to be driving it down in the cylinder, rotating the crank shaft, etc.
The fight is called pre-ignition, pinging or rod knock. Nucka, nucka, nucka especially from a low speed in say third gear. If you had a cylinder head temp gauge you'd see it go higher.
You can adjust the timing a dab or move up to the next higher octane on your next pit stop.
If there's a point to this it's just to know the right octane to buy is the lowest one that doesn't make knocking noises. The engine has no idea from higher octane, or flavors, or freshness tasty.
Read the plugs. Grey brown with a few deposits is good. Glazed, very white core, few deposits needs Bosch WR9 DS, correct timing, probably higher octane.
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JamusMcFamus
- Posts: 98
- Joined: Sun Jul 31, 2011 9:42 pm
- Location: North Augusta, SC