Is Leaded Gasoline Still Available?

[teleute12]

I stopped at a gas station that I don't normally go to and got a few bucks worth of gas the other morning.

As I was pumping the gas, I was looking at the pump and the labels. Turns out that the gas I had chosen was labeled "Regular Leaded." My car has the standard notice on the dashboard, "Unleaded Fuel Only" and I got to wondering. I hadn't known leaded gas to be available anywhere for the last dozen years or so.

A) Is leaded gasoline still available for purchase in the US?

B) If it was indeed leaded gasoline, will the 2.044 gallons that I put in my car going to hurt it?

[Reeder]

A) Is leaded gasoline still available for purchase in the US?

No. Not in the US. You can buy a lead additive though.





B) If it was indeed leaded gasoline, will the 2.044 gallons that I put in my car going to hurt it?

No.

[Cunctator]

Aren't the petrol bowser nozzles different sizes to prevent leaded fuel being put into an unleaded car?

[Q.E.D.]

A) Yes, but only for airplane fuel. Tetra ethyl lead is an antiknock (octane booster) additive. Today's automotive gasoline and octane boosting additives do not contain lead.

B) It wasn't - my WAG is that it was probably an older pump which was never upgraded. But, even if it was, a couple gallons probably aren't going to do any permanent damage. Extended use would eventually clog the catalytic converter.

[Berkut]

Yeah, leaded nozzles are much bigger.

[Diceman]

Originally Posted by Cunctator

Aren't the petrol bowser nozzles different sizes to prevent leaded fuel being put into an unleaded car?

I was a really young kid when I last saw leaded gasoline, but I don't think there was any difference in nozzle size. IIRC, you just had to read the label on the pump.

[Q.E.D.]

Originally Posted by Diceman

I was a really young kid when I last saw leaded gasoline, but I don't think there was any difference in nozzle size. IIRC, you just had to read the label on the pump.

I'm pretty sure there was. The problem wasn't putting leaded in an unleaded car accidentally, since the leaded nozzle was larger; it was putting unleaded in a leaded car, which caused valve seat erosion problems, IIRC.

[olefin]

Yes, back when unleaded gas become available the fill nozzle was smaller than the leaded gas nozzle.

In 1976 I bought a new Ford, it was designed for unleaded gas only.
Unleaded gas back then was much higher than leaded gas. So I knocked out the small nozzle reducer in the gas tank fill tube so I could burn the lower priced leaded gas. I put about 90,000 miles on that car before trading it for a new one. Never a problem with the car, I'm sure the catalytic converter had ceased to function.

By the time I bought my next new car the price for unleaded and leaded was the same so I started burning unleaded.

I haven't seem any leaded gas for sale in several years.

[jasonh300]

Originally Posted by Q.E.D.

I'm pretty sure there was. The problem wasn't putting leaded in an unleaded car accidentally, since the leaded nozzle was larger; it was putting unleaded in a leaded car, which caused valve seat erosion problems, IIRC.

Having owned a couple of old cars that were designed for leaded gasoline, I can testify that the filler hole is really big compared to the unleaded fuel nozzle. I also can remember pumping gas as a child (back in the 70s, they didn't freak out about that sort of thing) and the leaded nozzle was much bigger and wouldn't fit into a car that took unleaded. They even sold an "emergency" adapter so that you could put leaded gas into an unleaded car in an "emergency" situation.

Nowadays, if you have an old car that is designed for leaded gas, you have no choice but to put unleaded in, and they run fine, but it's a good idea to put the lead additive in every few tanks, otherwise bad things will eventually happen....perhaps the valve seat erosion, but I don't remember exactly what. Haven't had a car that old in about 10 years.

Jason

[postcards]

But doesn't leaded gasoline do nasty things to your catylitic converter?

[jasonh300]

Originally Posted by postcards

But doesn't leaded gasoline do nasty things to your catylitic converter?

Yes, if you use it all the time. I think it renders the catalytic converter useless...which will happen eventually anyway.

But cars that used Leaded gasoline didn't have catalytic converters.

[Berkut]

Hard on oxygen sensors too.

[Rick]

OK, here is the deal.
Leaded gas for automotive use has not been sold in the US for many years (last leaded gas was sometime in the 80's IIRC)
Leaded gas has a much larger nozzle than unleaded pumps, this was done to prevent the introduction of leaded gas into an unleaded car.
Unleaded gas still uses the smaller nozzle. Cars still have a restrictor to prevent the introduction of fuel from the larger leaded nozzles.
Leaded gas won't "hurt" an unleaded engine unless you consider the fact that the lead will foul the oxygen sensors and destroy the usefulness of the catalytic converter in a fairly short order. Would 2 gallons do this? Don't know, but with the cost of new oxygen sensors and converters, this is not an experiment that I am planning to undertake.
And last but not least, Catalytic converters don't wear out. A catalyst is not used up in a chemical reaction. I have seen many cars with more than 200,00 miles that are still using as original converters, and will still pass California emission tests. My daughter's car has 140,000 miles and passed its last smog test with almost zeros (0.01PPM CO, 10 PPM HC, 10 PPM NOX). Mis-fueling (when leaded gas was available), misfire, and other issues with the engine can however kill them in short order.
Bottom line, unless you bought gas at an airport, it is almost 100% certain that you got unleaded gas.

[engineer_comp_geek]

I have a kit car that is basically a very much modified 1960 VW beetle, which of course was designed to run on leaded gas. From what I've been able to figure out, if you don't drive the car much, unleaded gasoline isn't going to do much damage, so it really doesn't matter much for old collector type cars like what I have. If you do drive it a lot, you've got a choice of either using a lead additive or replacing the valves with stronger ones.

[Blown & Injected]

Leaded gas is most certainly being sold for cars - race cars. I know lots of people that run leaded gas in their car while at the track. They make it thru about 30 gallons before the O2 sensor starts to get lazy. I keep the blower pressure low enough for the unleaded stuff to work

Several types of leaded fuel here: http://www.racegas.com/fuelspecs/default.asp

[threemae]

Okay, so leaded gas was phased out for environmental concerns, correct?

When people say leaded, they certainly don't mean acual, elemental lead, do they? What exactly is leaded gas?

[Hail Ants]

When people say leaded, they certainly don't mean acual, elemental lead, do they?

Yup, that's precisely what they mean. Lead. Like the stuff that used to be in paint chips.

In fact Tetra-Ethyl Lead is incredibly poisonous. A small, concentrated amount on your skin can kill you.

[Mangetout]

Originally Posted by threemae

Okay, so leaded gas was phased out for environmental concerns, correct?

AFAIK, not exclusively because of environmental problems in the sense of birds and flowers, but pollution of the human environment - cars and humans share a lot of space and humans (particularly the small kind) are somewhat susceptible to problems associated with lead compounds.

[Roches]

Leaded gasoline contains tetraethyllead (technically, tetraethyl lead(IV)), (CH₃CH₂)₄Pb. It would be highly toxic, since the ethyl groups would help it dissolve in organic material. The lead itself doesn't contribute to the substance's antiknock properties. In the engine, the four ethyl groups in tetraethyllead break off, forming ethyl radicals, CH₃CH₂^.. The ethyl radicals aid in the combustion of the fuel by promoting its breaking down into smaller components. When fuels burn, they break apart into radicals -- for example, six-carbon hexane might break into a four-carbon and a two-carbon radical. The radicals combine with oxygen much more easily than the fuels themselves; eventually, you get one-carbon radicals, and these combine with oxygen to form carbon dioxide. (Or a multiple-carbon radical could break apart -- forming carbon dioxide and releasing energy is the point.)

The ethyl radicals from tetraethyllead help to initiate this process. This makes components of the fuel that do not easily break down (straight-chain fuels, which normally cause knocking in a gasoline engine) to break down more easily. Highly branched fuels break down more readily than straight-chain fuels; they have higher octane ratings (i.e. better anti-knock properties). Tetraethyllead makes straight-chain components break apart more like branched-chain ones; therefore, it increases the fuel's octane rating. The lead, as I mentioned, does nothing to contribute. I'm not entirely sure how unleaded fuels achieve the same octane ratings; additives such as MTBE probably are a part of it, and refineries might produce fuels with more branched-chain components as well.

[malden]

I don't know if it's still being sold today, but I did encounter leaded gas as recently as 1995 on the Navajo Reservation in Arizona. I pulled into a gas station and started to select the pump marked "regular," which nowadays means basic unleaded gas, but back in the "old days" of both leaded and unleaded gas meant leaded. At this station, the latter convention was still in effect. I got as far as pulling out the nozzle and moving towards my car when I noticed the sign indicating it was leaded gas. I thought I had barely missed destroying my car's fuel system, but later I learned that the nozzle would not have fit in my tank, a design move intended to prevent that from happening.

I was surprised that leaded gas was still for sale-- I hadn't seen any sold since early childhood (mid-late seventies.) On subsequent drives out to Arizona I have not noticed leaded gas for sale, but I didn't go out of my way to look for it, either.

[elmwood]

Originally Posted by malden

I don't know if it's still being sold today, but I did encounter leaded gas as recently as 1995 on the Navajo Reservation in Arizona.

Honest-to-goodness leaded gasoline was still available at many gas stations in Las Cruces, New Mexico in 1993. When I moved there in 1989, I thought the availabilty of leaded gas was very unusual; leaded gas stopped being sold in New York in the early 1980s IIRC.

To this day, I hear a lot of old people refer to premium gasoline as "ethel" or "high test."

[cornflakes]

In 1987, I was told in my mechanics training that the leaded gas sold had virtually no tetraethyl lead. Leaded gas was completely phased out at the end of that year. If any pump gas in the U.S. has lead in it then it was added in violation of EPA regulations. More likely, the owner just never bothered with replacing the sticker on the pump.

Lead was added to gasoline for two reasons, to reduce detonation (i.e. to increase octane) and to protect the engines' exhaust valves. As the exhaust valves of an engine open and close, they're alternately heated by the exhaust gases that blow past and then pressed against the iron of the heads. The valves in older engines were made of untreated steel and the heads were iron alloy. Without tetraethyl lead, the valves would weld themselves to the head much in the same way that a blacksmith welds steel by heating it in a furnace then hammering it together. Over time this destroys the valves and seating areas.

Lead was added to gas to perform a chemical vapor deposition. The lead is vaporized during combustion, is deposited on the valves, and the softer lead creates a barrier layer that keeps the valves and head from bonding together.

Lead in pump gas was phased out for two reasons. First, lead was released into the general environment. Second, besides coating the exhaust valves the lead also coated the pellets in catalytic convertors and (in later models of cars) it coated oxygen sensors, so not only was lead sent out the tailpipe, the emissions controls in a car were destroyed.

Other additives have replaced lead as octane enhancers (I think that MTBE has been banned as well.) The exhaust valves and seats are now made out of harder materials.

[cornflakes]

Link

-In 1973, EPA initiated incremental reduction of TEL in gas.
In 1982, leaded gasoline contained 1.25 gram/gal (& accounted for 86% of the lead in the atmosphere).

-By 1986, down to 0.1 gram/gal. But by then, lead used in U.S. gasoline since 1920s totaled 7 million metric tons (15.4 billion pounds)!

-Since 31 December 1995 it has been illegal to sell for use in on-road vehicles any gasoline which contains lead or lead additives. (But in 1999 leaded gasoline still is produced in the U.S. and is being used in nonroad vehicles-- primarily as aviation fuel, but also in farm machinery and race cars.)

Admittedly, this is a biased source, but I don't think that they would fudge facts that were this easily refuted.

[Diceman]

I guess I was wrong about the nozzels. But like I said, it's been years and years and years since I've seen a pump for leaded gas. (I think it was phased out in the early 80's around here.)

On a technical note, does anyone know how leaded gas ruins a catalytic converter? Does the lead react with the catalyst and spoil it, or is it more a matter of lead deposits gunking up the works? To use engineering jargon, does lead poison the catalyst or foul it?

[cornflakes]

It coats the catalyst.

[BobT]

The low down on leaded gas from the EPA

http://www.epa.gov/history/topics/lead/02.htm

[DrMatrix]

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