Re: Musings on Nearly Going Up in a 50-Ft Fireball!
Since we're talking about the fuel we fly with, let's not paint 100LL with too broad a brush.
"Point is: proper mitigation likely does greatly reduce known bad effects of leaded gas and one is probably assured of getting a cleaner, more consistently good & safe product (in the 100LL)."
Not all 100LL fuel farms provide the same delivered fuel quality, even if the original fuel source is the same. The care given the fuel in transport (what did the tanker carry last month...?), the filtering done on transfer to the tanker (if any) and the health of the airport's 100LL tank, the quality checks done (or not) by the FBO staff when fuel is delivered, and the quality of filtering as the fuel is pumped into our a/c tanks are all variables. I think I mentioned a while back that the staff at my rural airport just outside Jacksonville (KHEG) carefully inspects each fuel delivery, both Jet A and 100LL. When the 100LL doesn't pass their quality check, it's then delivered further south to another rural airport about 30 miles away (42J) where the fuel price is (not surprisingly) cheaper.
I don't know how we adjust our purchasing practices to insure good 100LL fuel quality except by word of mouth, but that doesn't work once you leave your local area. We fly across the country somewhat regularly and I always wonder, when picking fuel stops using Foreflight, if I'm actually making a poor decision to save a few bucks. On one trip we ran into some stinky weather in MO and had to divert, using a VOR approach into this small town airport and wait out front. The fuel was astoundingly cheap; I mean like $1/gal less than the best prices we'd been finding elsewhere. When I mentioned it to the FBO manager, she commented they hadn't had a fuel delivery in a long, long time. Gulp!
Good points about 100LL, Jack. Come to think of it, I do recall getting an ounce of grit with my 5-gallons (in a jug), a couple times from a local "cheapo" FBO pump. And I've wondered how long fuel has been sitting in tanks at some relatively lightly-used APs I fly to.
As a dealer for Phillips 66 I have to add fuel to the tank at a minimum of every nine months. That being said I have seen airplanes sit for 5 years with 100LL in the tank, and fire right up with no issues. It has a very long shelf life compared to auto fuel.