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Comment by gambiting | Hacker News Reader

I have a fun trivia fact to share actually - here in UK, it's one of the only remaining places in the world where you can still legally buy leaded petrol for automotive use. Only a handful of garages around the country are certified to sell it, the prices are very high, but it's the ultimate fuel for people who want to preserve their old vehicles in original factory state, without modifying anything to run on unleaded fuel. Alternatively, the sale of leaded additive is still allowed(which literally just contains TEL - tetraethyl lead - effectively turning 95 unleaded into the old 4-star leaded).

This website used to list the garages still selling leaded petrol, but they have changed the whole site very recently - so you can only see the list on wayback machine:

http://web.archive.org/web/20210225112828/https://fbhvc.co.u...

TEL additive:

https://www.classic-oils.net/TetraBOOST-E-Guard-15

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In London last summer I caught a whiff of a smell that I hadn't smelled in years - 30 seconds later a vintage Jag came around the corner and I realised it was the exhaust of a car running leaded petrol. I was struck by the fact that I could literally smell it coming.

That may have been from uncatalysed exhaust. My '66 Mustang also has a very distinctive smell, despite running an unleaded fuel.

Sweet smell can also be from running ethanol-rich fuels.

Which is kind of interesting in this regard. Brazil converted a large portion of its passenger car fleet to ethanol and it seemed a better overall fuel, to the point some sportier models had only ethanol versions.

Wouldn’t ethanol be an adequate substitute for avgas with property adapted engines?

Ethanol is a terrible substitute for gasoline. It has something like 70% the energy density of gas, it readily absorbs water from the air, which means it also corrosive.

The main reason it works in Brazil is because they can make it cheaply from sugar cane. In the U.S., ethanol is just a highly inefficient subsidy for corn farmers.

> It has something like 70% the energy density of gas

That's true - when running on ethanol, range is shorter. OTOH, it allows higher compression than gasoline - which is why some cars came with ethanol-only engines. When disassembling engines, we also note there is much less, if any, deposits.

> also corrosive.

This was solved (in cars) in the late 1970's.

> In the U.S., ethanol is just a highly inefficient subsidy for corn farmers.

Maybe not worth it for cars (especially now that we have viable batteries for EVs) but these are different markets.

The moisture thing alone would be a deal-breaker for avgas. You really don't want to have engine trouble mid-flight and avgas has special anti corrosion compounds afaik.

We always topped up the aircraft tanks every time to minimise condensation.

This video was crazy, making ethanol from Corn provides something like 1% of the power of the sun hitting the square meter of farm used for it. Meanwhile using tonnes of water, space, and other things. It's basically a terrible idea over-all given alternatives like electricity and solar power.

And it mostly only works because its government subsidised.

But watch the video for the full story: Real Engineering - Why Biofuels Are Terrible https://www.youtube.com/watch?v=OpEB6hCpIGM

Ag subsidies in the US are pretty wild.

One study said that 75% of the price of dairy was subsidized. The fact that I haven't heard of any other studies (or that you even need a study to determine such a number) is a bizarre red flag by itself.

Can someone who understands the political history around this explain why this is still legal in the UK?

It's my understanding that no level of lead exposure is safe.

Lobbying from interested parties. In this case, the Classic Car enthusiasts. The government most likely judged that allowing a dispensation for commercial sale would not in fact result in widespread continued use of leaded fuel due to the commercial realities of selling such a niche product, but it was worth the effort to say they supported this niche - and that's exactly how it turned out.

The original 1999 UK legislation envisions retailers will be given a maximum quota on how much leaded they can sell, a permit holder could sell 0.5% of volume per month for example. But as anticipated ordinary motorists just put unleaded in the tank and carried on as before so the quota system was pointless. If your "quota" is 10 000 litres of leaded fuel per month and you sold a total of 45 litres to one bloke in that time, you not only don't need a bigger quota, you won't order any more of that fuel from your supplier. If perhaps, the next summer, a motorist in a Victorian outfit driving a 1926 Chevrolet enquires about the leaded fuel you tell them "Sorry mate, we're out of stock" and most likely they put unleaded in the tank, but either way they're not wasting your time and money with this weird "leaded" fuel nobody buys.

Which is why there was an archive.org link above -- the actual site for the FBHVC now tells you that you probably can't get leaded fuel, and even if you could you shouldn't bother, even though that's the organisation identified in the legislation itself as asking for this exception.

I assume it's still technically legal for whoever actually bothered to have a permit - but the actual emissions involved must be pretty tiny.

No level of car exposure is safe, but we still allow people with the right licenses to drive on the roads.

The UK has a long tradition of massive taxes rather than outright bans. E.g. absinthe was never illegal there, unlike many countries, it just had a punitive level of duty put on it.

Right, but we don't have any economically viable alternative to cars. If we outlaw cars, then what?

If you put actual effort into not having cars, you'd find a way to make it work. Plenty of people do. At the least you could have stricter driving tests and jail drivers who kill pedestrians.

corruption. its use in aviation - and use of other chemicals involved in their engines - is not safe at all either -

https://www.latimes.com/projects/toxic-chemicals-planes-covi...

https://www.bbc.com/news/stories-51633897

oil-in-cabin-air issues are solved by not using bleed air for cabin pressurization.

I think that has problems which prohibit it from being implemented. I think a better option to just pass the air through a filter to remove oil particles before the air is used in the cabin.

IIRC it's not particles, but combustion/decomposition products.

And no, it's not an issue with using non-engine air for cabin pressurization taking too much weight/power: even a large airplane needs only little actual airflow.

Cynically, my guess is that the laws were passed by classic car owners. There have been similar looking dispensations on road tax for classic cars in the past.

Is there a https://www.howmanyleft.co.uk for numbers of leaded petrol cars still on the road?

Not sure if that would be useful, as there's no way to confirm whether a vehicle that was designed for leaded fuel was converted for unleaded, or if it simply runs on non-leaded additives.

Either way, there is this website, which used to really push for leaded petrol, it disappeared in 2009, but it almost reads like comedy:

http://web.archive.org/web/20090101030343/http://www.leadedp...

" Don't forget, if your local filling station doesn't sell leaded petrol, ask them to start!"

"Bayford is campaigning to have the extra duty on Leaded Petrol removed. You can help by printing this letter and sending it to your Member of Parliament"

"If you run a classic or high performance car, now is the time to throw away that can of additive, and fill up with award winning genuine leaded petrol"

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