Gas Cap Minimum Fuel Engraving

[macrafic]

According to the latest Lycoming 1070 Service Instruction, the following are the minimum fuels allowed for my engine (IO-360-M).

Question: If I want to placard my fuel tank caps with a minimum fuel number, what would be appropriate? The minimum depends on leaded/unleaded and on Avgas/Mogas selection. Can only fit so much on the cap!! If I put MIN 100LL or MIN UL91, does that preclude me from using other allowed fuels? What have you done?

Avgas (leaded):100, 100LL, 100VLL satisfying ASTM D910 specs (Standard Specification for Aviation Gasolines)

Avgas (unleaded): UL91 satisfying ASTM D7547 specs (Standard Specification for Unleaded Aviation Gasolines)

Mogas (leaded): 93 AKI* satisfying ASTM D4814-09b specs (Standard Specification for Automotive Spark-Ignition Engine Fuel)

Mogas (unleaded): 93 AKI* satisfying EN 228:2014 specs (Automotive fuesl ? Unleaded petrol ? Requirements and test methods)
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[RV7A Flyer]

100LL 21 US GAL
N-NUMBER

It's *my* plane...so I'm the only one who fuels it. I don't trust the monkeys at the FBOs, seen too much hangar rash in my time.

So I figure it's not really a big deal...if I were ever to try the UL92, I'm not going to prevent myself from fueling my plane because of a sticker or engraving.

If you often let others or FBOs fuel your plane, you might run into some who won't or can't if the placard is set up a certain way. E.g., if it says "100LL", but you want them to put in UL92. They may not be able to legally, dunno.

[flyboy1963]

notwithstanding 'the law', I've marked my fuel filler with
'min. 80 octane' per the data plate on my engine. ( lycosaur)

Is whether it's leaded or UL relevant to the fueler?

If you want to anticipate the fuels changing, don't engrave the caps, just use a decal. Mine are the ring type on the tank itself, they've stood up remarkably well....pretty cheap to replace from time to time.

[Mel]

I might suggest that you NOT put "LL", "UL", or anything mentioning lead content on your fuel placard. If you do, what will you do when "LL" goes away.
You are only required to label "minimum octane, and quantity".

[RV7A Flyer]

Originally Posted by Mel

...what will you do when "LL" goes away.

Buy two new caps. In the grand scheme of the small fortune it seems I've spent on aviation, two new fuel caps are pocket change.

[Mel]

Originally Posted by RV7A Flyer

Buy two new caps. In the grand scheme of the small fortune it seems I've spent on aviation, two new fuel caps are pocket change.

Yep! Sounds like the fuel cap engraving market will really open up.

[rightrudder]

Fill in the "LL" with JB-Weld, and sand smooth. Fixed!