Chevy Impala

[MasterBlaster]

Note that mixing octane grades does not yield the average octane equivalent. An octane rating expresses a resistance to ignition, higher octane is less likely to ignite prematurely. Mixing low octane into high octane gas causes that high octane gas to ignite much sooner than the average of the two grades. Half 87 and half 93 might ignite something like octane 87.5.

The octane calculator at Bazelle Race fuels suggests that what you posted is NOT true. The calculator suggests that mixing 87 and 91 octane gasoline in equal parts gives exactly 89 octane.

Octane Calculator - www.bazellracefuels.com


The website on Sunoco race fuels also supports that an even mix of 91 and 87 octane gives a result of 89 octane


https://www.sunocoracefuels.com/tech-article/mixing-fuels-calculating-octane


First you need to calculate the percentage of each fuel that will be in the final mixture. Then, use this equation to find your octane:
( [ % Fuel A ] x [ Octane of Fuel A ] ) + ( [ % Fuel B ] x [ Octane of Fuel B ] ) = Octane of Mixture

 

[Andre1969]

Blending can work to lower octane, but the ratio is important. To change 93 octane into 89 octane perhaps you add 10% of 87. I don't know the proper ratio, but the concept I learned in high school chemistry.

I wonder if the formula is something akin to "weighted average", for MPG?


To use an extreme example, if a car gets 10 mpg, over the course of 100 miles, and then gets 20 mpg over the next 100 miles, its average MPG isn't 15 mpg, but 13.333? Could the octane blending be the same general idea as that?

 

[GrayHare]

Interesting about that calculator and Sunoco info. It does not match my understanding of chemistry, so I'll have to study this more.

For example, all/most of a can of gasoline will combust upon ignition that starts with any molecule anywhere within the liquid. Since lower octane ignites more easily, its molecules ignite earlier, and set off the rest, even molecules of a higher octane that would have resisted the ignition. Similar happens in an ICE cylinder. As most car people here know, the timing of the ignition is important for proper engine operation and maximum conversion of chemical to mechanical energy.

 

[Winemaker]

In winemaking, we use Pearson's Square for blending to control alcohol, brix, and acid, which are all chemical properties.

Flavor and aroma is up to winemaker.

Varietal percentages are controlled by federal law.

 

[Tom52]

My first car in high school and into college was a '62 Impala. Bought for $150 and sold for $150. Wish I'd have kept it, but it was pretty beat up by 1976.

I had one as well. I wish I still had it. Probably worth about $75,000 today.

 

[Tom52]

My first car was a 67 impala. Great car. 150k miles in 1974, so I traded it for a nova. Got $150 for the impala. Should have kept it. Even though it had been in a few wrecks, had some rust, and only ran on 7 cylinders after I broke off a spark plug. And I used to be able to start it without a key.

While I'm at it I might as well show you the 67 Impala Super Sport I had. Rust free California car. I've had several more Impalas besides the 62, 65, and 67. They were/are all show quality cars.

 

[HFWR]

I had one as well. I wish I still had it. Probably worth about $75,000 today.

My first car was a ‘62 Belair, two door post, three-on-the-tree, 283, 2-bbl.