Gasoline Tech

FWIW, here is a link to Chevron Motor Gasoline Tech Review

This is one of the best (and easiest) articles I have read about gasoline distillation profiles, and other interesting gasoline facts.

http://www.chevronwithtechron.ca/products/documents/69083_MotorGas_Tech_Review.pdf

That is good! Thanks for posting.
It helps both on the street and on the track to understand how gasolines can differ. It's a real PIA when the weather and the pump (street) gas don't match up.

Tech data for race fuels seems to be pretty readily available as the manufacturers post on the websites and have tech reps available.
If you come across any info from much earlier (1960s-70s) or current street fuels, let us know. I've graphed some distillation curves and posted them on RFS, but the street gasoline info may not be representative of what is actually sold today. Perhaps that will always be the case with so many fuel regions and weather..

http://racingfuelsystems.myfunforum.org/viewtopic.php?f=23&t=579

I actually ran across this Tech review a few years ago, and found it insightful on how the gasoline is blended and why, and how each part of the mix changes the fuel.

If you start searching into this, there is alot of politics you will run across, but one interesting item I read is that the US has somewhere between 45 and 75 different pump gas blends, and also depending on the blend, like winter blend, the stoichiometric ratio is lower than the common quoted 14.7:1, somewhere around 14.3 to 14.4:1.

I don't know how old or accurate this post is, but this was the source:
http://zhome.com/ZCMnL/PICS/winterGas/winterGas.html

I worked in the fuel lab for 35 years so I have a pretty
good handle on the fuel aspect.. I did tons of hot and
cold fuel testing.. we(Chrysler) and the fuel companies
had to deal with each other closely over the years
and still do

Sure is a lot of politics and economic incentives as well. Some of the studies I found were sponsored by engine manufactures such Mercury Marine and others by the Ethanol Council to name just two with obvious self-interest in the results done by otherwise independent academics or researchers.

I haven't taken as many notes on the Stoich or density for the various fuels but they definately vary from 14.7:1.
Eventually I'll start using Lamda instead of AFR (maybe) but until then I do keep it in mind not consider anything logged as AFR an absolute number.

FWIW, Sunoco Racing Fuels specs a stoich of 14.1 and SG of 7.34 for 260 GT which is oxygenated with nearly 10% ethanol.
Wheras their 260 GTX (non-oxygenated) is 14.6 and 7.64
And Standard (leaded) has a stoich of 15:1 and SG 7.29