Leaded gas exhaust and Kids

Came across this thread on reddit about NASCAR’s switch from leaded to unleaded, and the difference it’s had on children raised nearby. We’ve always known about the problems of the entire country running leaded gas, but this shows exposure to a few dozen cars driving around once every few weeks is enough to make kids dumber.

I saw the thread about SKUSA testing unleaded for X30. It looks like it’s now the official spec fuel, but it doesn’t appear to have made much of a dent nationally or to other 2-stroke engines.

So, my question: Is there anything I can do to protect my kids from leaded gas exposure at the track?

Getting them to wear giant respirators seems like a no-go – do those every day KN95 covid masks do anything for lead? What about using blower fans to blow fumes away from my pit area? Is a practice day, which tends to have very few 2-strokes, considered “safe” or does it kick up lead into the air all the same? Anyone tried convincing a local track to switch to the SKUSA spec fuel?


It’s pretty incredible to me that it’s still allowed, especially around developing brains.

Two strokes (Even the high revving 100cc classes) in Europe have been unleaded since the early 90’s.

Of note there’s a discussion here: Leaded Race Fuel

I’m not sure what mask would work with the lead from burned gas/TEL, interesting question.

My solution was to not take the kids to the track anymore and just build my own.

That said, I’m not too keen on going racing again myself with leaded fuel. I used to road race where you’re drafting a lot. The engine nut in me loves the smell of leaded gas. Two strokes especially love it as the lead forms a dry lube.

However I have a family history of cognitive decline that I’d rather not accelerate.

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I think about this having a young child that may or may not be interested in racing in the coming years. I won’t be taking her racing until unleaded is more widely adopted. Hopefully other series and clubs will follow SKUSA’s lead soon.


Yes. Use Marathon/Speedway/Arco 93 octane E10 premium gasoline for racing and don’t bother with expensive fuel in a can. If your track requires something else, have the owner talk to someone at Marathon Petroleum.

It’s incredible for an outsider how low the octane is in the US. In NZ, our lowest grade pump gas is 91, middle grade is 95 and our top grade is 98. All are unleaded and contain no ethanol. We even have a 100 octane option now, also with no ethanol.

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Same here, leaded doesn’t even exist. I’ve only ever put pump gas into my x30, 98.

The difference you’re seeing could be due to how that “marketed” octane number is attained. Not all octanes are equivalent. UK 91 and US 91 are not the same for example.

There’s AKI, RON, MON (and maybe more). US is RON+MON/2


Different measurement scale, similar fuel.

Regular gas in the US: 87 AKI / 91 RON
Regular gas elsewhere: 90-92 RON

Premium gas in California: 91 AKI / 94 RON
Premium gas in the eastern US: 93 AKI / 97-100 RON
Marathon Premium E10 from the Detroit refinery: 93+ AKI / 101 RON
Premium gas elsewhere: 97-100 RON

Blue Avgas: 107 AKI / 115 RON (but absolutely terrible performance)

Ethanol is a performance-enhancing chemical in gasoline. Leaving any fuel in a carburetor after use will cause reduced performance and engine failure.

We get stuck with leaded gas in American racing for two reasons:

  1. Political affiliation of series organizers
  2. Lack of trust of anything sold at a pump rather than in a drum
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Right; without getting technical, 95 octane in Europe/etc is the same as 91 octane in the US. In the US, we can get unleaded high octane gas out of a drum… we just choose not to.

FWIW, my own kids drive 4-strokes, but there are a lot of 2-strokes at races and they tend to warm their engines in the pit area and blow exhaust everywhere.

Karting, where you can trust your friends to go side-by-side with you around a 2g turn at freeway speed but not to fill up at Pump #4 at the Marathon station two miles at the track.

Every vendor sells unleaded race gas in drums, but it’s more expensive than leaded race gas.

I do think it is pretty crazy the karting community in the US is just okay with the leaded gas… Especially with the younger kids hanging around. With bigger race series like Nascar moving to unleaded, is there any momentum or opportunity for the karting community to switch as well?

I talked to my 12 yr old son about lead and what it can do to our bodies. He’s now worried about the lead weights on his kart.
I grew up in Germany and when I was young we all drove leaded fuel. A study recently stated that I am probably 2-3 points dumber :frowning: .
Privat air planes with piston engines run leaded fuel, even today.
Racecars, at least with modern engines can not run leaded fuels due to its oxygen sensor. They do not like the leaded fuel and will fail.
MotoGP switched to unleaded fuel when they were still 500ccm 2 stroke, that was in the 90s???
I hope that such fuels will be made illegal asap.
BTW Methanol is also bad, it can make you blind.

Wow! Leaded fuel in Australia was phased out in the early nineties and completely removed from the market in 2002.
From what I’ve found worldwide production actually stopped in 2021. Is that wrong?
Not only has it been linked to poor learning outcomes. It’s also been linked to higher crime rates. Removing leaded fuel from the market takes 20 to 30 years to show results so maybe the studies are a bit premature.
All this said I doubt that racing a kart would have increased exposure much more that waiting at a bus stop or sitting in commuter traffic.

In the US leaded fuel was banned in 1996 - except for racing, farm equipment, marine, and aviation. Aviation being really the worst next to karting as the so-called 100 low-lead actually should be called high-lead. Thankfully the FAA has finally approved an unleaded substitute for that, although distribution will take time.

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As I child we had to leave Los Angeles in the 70s. The air pollution was so bad that the doctors advised we move. I used to get persistent eye infections from the air.

There is an excellent episode of Cosmos where NDT recounts the challenges faced by a scientist that discovers the lead everywhere through core drilling of ice in arctic. It’s a very good explanation of what went down.


This is top of my mind right now, as my son is moving into Jr. 1 next season, and wants to run 2-stroke. We’re planning on running unleaded 91/93, but the concern is more around everyone else and the fumes when the karts are gridded-up at the beginning of races, and in the pits.

I’ve talked to other parents and even a team owner. Conflicting thoughts/opinions. The team owner mentioned that he had parents that had tested their kid’s levels, and the only noticeable increase in lead exposure was during Rok the Rio (lots more karts, stale air between the buildings).

I’ve even thought about getting some sort of lead-deterring mask that my son could wear when racing, but then you start to think about the respiratory affects of having a mask and a helmet on…

Any parents of kids have any thoughts into how to at least reduce the effects of leaded fuel fumes? Is 4-stroke the only answer?

See this need to test SHOULD NOT EVEN BE A THING


Wholeheartedly agree

Ok. I’m writing to all of the oil companies that serve SoCal to get a sponsor.

We’re holding the 91 Octane Challenge, either at K1 Winchester if I can rent it or at Grange if I can’t.

Fuel will be from a specified pump at a specified station. Receipts will be checked at registration and fuel tech will be stringent enough that I recommend draining and washing both your jug and your tank a week before the race and leaving them open to dry. The entry fee will include a bottle of good oil - Elf if I can get enough, Maxima or Motul if I can’t. Tires will be specified and I’ll choose one that’s readily available (probably MG).

Classes will be set for the engines that require 95 RON or less in their manuals.

Adult Open, no ballast
RoK Shifter at 380 lbs
Senior TaG 125 (Rotax Max Evo and X30 at 370 lbs)
Masters TaG (Rotax Max Evo and X30 at 400 lbs)
Junior TaG 125 (Rotax Max Jr Evo at 320 lbs, X30 Junior at 330 lbs)
Open Cadet, any engine less powerful than a Junior TaG, no ballast

Prizes for 1st thru 3rd in all classes will be a little silver-plated medallion with “91” on one side and the sponsor’s name on the other.

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It’s going to take getting the series and tracks on board, as many require racers to use the fuel on site.

I’ve reached out to some folks here in the Midwest that can hopefully help enact change. It will be good to also get the support of engine builders, as they are often viewed as the experts when it comes to engine fuel requirements.

Once we get enough people in the discussion as to the importance of this then I think it’s a pretty easy sell. It’s a safety concern for our kids, plain and simple.