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MGB Gas Octane for MGB's
- Thread starter tony barnhill
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swift6
Yoda
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MTBE shouldn't be anywhere anymore. They figured that it was bad for the environment. The 10% Ethanol we now have is not MTBE. In the broad strokes, it is 10% corn squeezin's while E85 is 85% of the same stuff. Old rubber bits in the fuel lines love to fall to pieces when presented with any of the ethanol. Fuel vaporization also happens at lower temps. So you are more apt to see vapor locks with this stuff. Add together high altitude, high summer heat and 10% ethanol fuel and you have a whole new range of tuning issues that we get to deal with.
My basic point with the first post was that we don't get the choice of searching out stations that don't mix their gasoline's with 10% ethanol. They all do it here. On the plus side I guess is that because of the politics surrounding it, all but three counties in Colorado no longer have an emissions test program. Although the scuttlebutt at the state level is that we might be getting a new statewide system that will be NOx based like California instead of our old CO based system.
My basic point with the first post was that we don't get the choice of searching out stations that don't mix their gasoline's with 10% ethanol. They all do it here. On the plus side I guess is that because of the politics surrounding it, all but three counties in Colorado no longer have an emissions test program. Although the scuttlebutt at the state level is that we might be getting a new statewide system that will be NOx based like California instead of our old CO based system.
RickB
Yoda
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I've used the 92 from Costco gas the past couple fill ups.
One thing I noticed is a bit of increased mpg. That's kind of nice, it does feel a little peppier also.
I probably break even at just 20 cents a gallon more than the 87 considering a little better mpg.
The cost is just 6.6% higher so that would break even if I increased from 23mpg to 24.5mpg - and hopefully my engine has other benefits from the 92. One thing for sure, the 92 gas can't hurt my car.
One thing I noticed is a bit of increased mpg. That's kind of nice, it does feel a little peppier also.
I probably break even at just 20 cents a gallon more than the 87 considering a little better mpg.
The cost is just 6.6% higher so that would break even if I increased from 23mpg to 24.5mpg - and hopefully my engine has other benefits from the 92. One thing for sure, the 92 gas can't hurt my car.
Mac_Townsend
Freshman Member
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I use 87, in a 9.x CR engine. No problem.
OP
tony barnhill
Great Pumpkin - R.I.P
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And just something else to add fuel to the fire (hehehe):
In my big Dodge truck, BP/Amoco gets the best gas mileage, Chevron/Texaco 2nd best, & Exxon a far 3rd! All the same octane rating.
In my big Dodge truck, BP/Amoco gets the best gas mileage, Chevron/Texaco 2nd best, & Exxon a far 3rd! All the same octane rating.
MGBGT_noob
Jedi Hopeful
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That's right. Look at the passage that says "93-octane Research". If you look at an American gas pump, you'll see that the label says "XX Octane (R+M)/2 method".
The R stands for "Research", a method of determining the knock-resistance of a give fuel formula, under "ideal" conditions.
The M stands for "Motor", a method that tries to measure performance under "real world" conditions.
The Motor octane rating of a given fuel almost always comes out lower than the Research rating. Therefore the (R+M)/2 number will fall halfway between the Motor and Research values. It all depends on the composition of the fuel. Some fuels have values closer together than others.
In Europe, they use the Research rating exclusively. Thus the US rating will usually come out lower for the same fuel. "93-octane Research" might equal 89 or 90 octane, (R+M)/2.
The R stands for "Research", a method of determining the knock-resistance of a give fuel formula, under "ideal" conditions.
The M stands for "Motor", a method that tries to measure performance under "real world" conditions.
The Motor octane rating of a given fuel almost always comes out lower than the Research rating. Therefore the (R+M)/2 number will fall halfway between the Motor and Research values. It all depends on the composition of the fuel. Some fuels have values closer together than others.
In Europe, they use the Research rating exclusively. Thus the US rating will usually come out lower for the same fuel. "93-octane Research" might equal 89 or 90 octane, (R+M)/2.
tony barnhill said: