The future of 100LL?

Does anyone have any knowledge regarding the future of 100LL? I heard the other day, that there was only 5-10 years worth of 100LL remaining! This would seem to put a dent in plans to buy an aircraft right now…Can someone please shed some light on this subject.

I thank you for taking the time to respond.

David, Cirrus SR22 Customer.

For an article on this subject from the May 2002 AOPA Pilot, click There’s also an “AOPA Regulatory Brief” about the future of 100LL available


What I’‘ve heard also a reason for the Klapmeier family not to produce a turbo version like the Columbia 400. Rumour is they don’'t work very well on replacement fuel.

For the oil companies, of-spec 100LL can only be sold in Africa, and has a negative value. That is why 100LL is produced by one in large quantities. And why there are discussions about availabilty for all other.



I remembering hearing the same thing when I started flying in 1990; that 100LL would be gone within 5 to 10 years. And now, 13 years later, we’re saying it will be gone within 5 to 10 years…

So I’m not sure about the time frame. However, surely at SOME point 100LL will really be gone. Either because of the scarcity of lead additive for the fuel, or because of regulatory restrictions on leaded fuel.

It is my understanding that most non-turbocharged engines will be able to run on some of the newer, alternative fuels like 92UL. I do not know specifically whether TCM’s IO-550 or IO-360 were ever tested on this fuel.

There is also a new system from the GAMI folks called PRISM which in theory allows even turbocharged engines to run on 92UL. Others surely know more about this than I do…


Okay… so my headline was “catchy” to get you to read this post. Sorry, but I am a “victim” of the influence of Captain Kangaroo, Sesame Street and our Liberal Media :wink:


I do not believe there is a “reserve” of fuel that will run out in 5 to 10 years. That’s not how the fuel production system works. Most gasoline you purchase is less than 30 days old. Aviation fuel is a little older but not more than 90 days.

The “problem” with 100LL is the additive, Tetrylethyl Lead. There is the belief that the EPA will mandate the phase out of leaded gasoline for off-road use in the next few years. The biggest issue is that only a few companies (I think only two, maybe only one) make the additive (Tetrylethyl Lead) and they see a declining market. It’s also expensive to manufacture and the class action lawyers are looking into the stuff as part of the lead paint litigation that is being bandied about (a suit was filed in Maryland over lead additives).

The use of lead additive in gasoline goes back to 1924… it’s an interesting story of corporate intrigue that conspiracy theorists love to talk about. (Prescott Bush, Sr. (yeah, the family tree of our prez), Saudi Pipelines, providing Tetrylethyl Lead to the Nazi’s for the European Invasion, etc.)

For an interesting yet possibly flawed report on the history of lead as an additive, follow this link:

(sorry, nothing about the Bush scandal in this one though you can find it on the web with a Google search on Prescott Bush, Sr., Conspiracy and perhaps Skull and Bones. BTW, I have not done enough research on this stuff (conspiracy theory) to form an educated opinion. I have more interesting things to learn about first and include the reference only as an invite for you to become more educated on the issue before forming an opinion. And, as Jim Fallows might admonish me, I have to tie the headline into the story in some manner!)

However, NASCAR is still a big user of leaded gasoline (must be something good about it) getting fuel up to 112 octane. So perhaps as long as NASCAR is popular we can get our lead we love so dearly.

On a more positive note, we are blessed to live in a capitalistic society where it is in someone’s best interest (economically) to find an alternative fuel or solution. As a result of this blessing we will all benefit as well and I believe we will find this debate to be interesting, but not relevant.


Ps - If you believe, after doing your resaearch, that the purchase of a piston powered airplane is a poor choice, then by all means do not purchase one. It may not be in your best interest to do so. After researching the subject, I have come to the conclusion that it is in my best interest to purchase one. If I have to buy a different engine (diesel, fussion, fuel cell, fission, etc) in 5 years, that is okay with me as well.

Therefore, if you are an entrepreneur and wish to invest your resources (time and money) in finding a superior alternative for 100LL, then I shall be pleased to join thousands of airplane owners in making you fabulously wealthy by purchasing your product. It’s my way of saying “thanks” for a job well done!

By then you will be ready for a new engine and most likely a deisel. So it wont realy be a big deal. From Don Owner of several trucks love the deisel moter there great.

Well, thank you for your responses, but frankly, it isn’t very encouraging is it?

Why would anyone choose to purchase a piston aircraft where the reality is that there will be an increasing fuel shortage, prices will increase with depleting supply and alternatives will drive the value of the aircraft down. I say very near, but for those who choose to buy aircraft and keep them, this is a REAL factor. I can’t assume anybody’s aircraft will sell for much when it comes time to replace it…or will owners simply replace their engine? Regardless, this seems like a quietly ignored issue.

Consider a business that wants to operate a fleet of piston aircraft for a number of years, this would seem particularly relevant.

I’d appreciate your thoughts?

Best, David.

This is most likely true to some degree. But if you realy like or need to fly then you do it and if you want a great airplane then you do it. I always am concerned about return value. But I try not to dwell on it or loose the joy. I some times frett over the high price of flying but My wife says I need the therapy in my time at the aiport and in and arround my plane. So I keep it and enjoy the value the most I can and it is great theripy. I never think about the cost or value when im near my plane. From Don


I don’t see a problem, nor do I think that people are ignoring this issue. New fuels (e. g. 92UL) will take the place of 100LL, and diesel engines which burn Jet-A will become increasingly available (they are available now in the Diamond DA40tdi). Even if gasoline for piston-engine airplanes were to disappear entirely, you’d be able to hang a diesel engine on your airplane and be good to go. (Keep in mind that the price of a new engine is a fraction of the price of an airplane, so this makes very good economic sense.)

My conclusion is that existing airframes are very unlikely to become extinct or even endangered in the event of the demise of 100LL.


I suppose my question becomes, when do we really expect to run out of 100LL (I understand there is an actual reserve that can measured) and if this is in the next 5-10 years, what other costs will be associated to that change?

Many thanks,

With all due respect, according to Cirrus, the price of a new diesel engine is much more than some used airplanes. Close to 100K currently from TCM. I think this is an issue and must be planned for. The aviation industry is notorious for ignoring the real cost of ownership.


…the price of a new diesel engine is much more than some used airplanes. Close to 100K currently from TCM.


To my understanding, TCM is a very long way from having a marketable aircraft diesel engine, so I suspect that it’s premature to quote prices for their products.

To date the only aircraft diesels that have been brought to market are the Centurion 1.7 (used in the Diamond DA40tdi) and the SR305 (which may eventually be used in the Cirrus SR21tdi). The 135-hp Thielert engine goes for 19,500€ (comparable to the price of a new Lycoming O-320, with which it is a direct competitor), while the 305-hp SR305 will probably be about four times as much (rather pricey). Thielert is also developing the 310-hp click hereCenturion 4.0, with a target price of 48,000€. All of these diesel engines have substantially lower fuel consumption than the 100LL engines that they replace.

For more details, see the article “Diesels Off the Block” in the August 2002 Aviation Consumer (subscribers click


These links are very informative, I welcome your thoughts…

Sorry, I’m not sure how to create an embedded link!