# Fill 'er up with ethyl? **URL:** \ **Category:** Factual Questions\ **Created:** [September 22, 2005, 2:30pm UTC](https://boards.straightdope.com/t/fill-er-up-with-ethyl/322886 "2005-09-22T14:30:54Z")\ **Posts on this page:** 11\ **Page:** 1
**Author:** ![CookingWithGas](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cookingwithgas/32/485_2.png) [@CookingWithGas](https://boards.straightdope.com/u/CookingWithGas)\ **Post date:** [September 22, 2005, 2:30pm UTC](https://boards.straightdope.com/t/fill-er-up-with-ethyl/322886/1 "2005-09-22T14:30:54Z")
I have a vague memory of gas stations many years ago (50’s, 60’s) offering up “ethyl” leading to the common phrase in the title. (Back in those days you actually had a person whose job was to put gas in your car and you told him how much.) But what was it? Cecil’s recent [classic column](http://www.straightdope.com/classics/a2_392b.html) on gasahol said that they started adding ethanol but that wasn’t until the 70’s (ethanol is also known as ethyl alcohol). So what were they talking about pre-70’s when they talked about ethyl gas? ---
**Author:** ![AHunter3](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ahunter3/32/368_2.png) [@AHunter3](https://boards.straightdope.com/u/AHunter3)\ **Post date:** [September 22, 2005, 2:36pm UTC](https://boards.straightdope.com/t/fill-er-up-with-ethyl/322886/2 "2005-09-22T14:36:22Z")
Tetraethyl lead. As in the opposite of unleaded gasoline. The lead additive had the same effect as refining to a purer proportion of octane, i.e., enabling the fuel to accept high compression without detonating (“knock”). ---
**Author:** ![FatBaldGuy](https://avatars.discourse-cdn.com/v4/letter/f/ecd19e/32.png) [@FatBaldGuy](https://boards.straightdope.com/u/FatBaldGuy)\ **Post date:** [September 22, 2005, 3:19pm UTC](https://boards.straightdope.com/t/fill-er-up-with-ethyl/322886/3 "2005-09-22T15:19:30Z")
Back in the “pre-unleaded” days, there were normally 2 grades of gasoline available, “regular” and “ethyl”. As **AHunter3** has stated, ethyl refered to tetraethyl lead. Even the regular grade had some lead, but the ethyl grade used more lead to boost the octane. ---
**Author:** ![justwannano](https://avatars.discourse-cdn.com/v4/letter/j/7ab992/32.png) [@justwannano](https://boards.straightdope.com/u/justwannano)\ **Post date:** [September 22, 2005, 3:37pm UTC](https://boards.straightdope.com/t/fill-er-up-with-ethyl/322886/4 "2005-09-22T15:37:04Z")
Both previous posters are correct. Ethyl was a brand name for the Ethyl corporation. They were a company that produced the additive. I never knew it by any other name. Some people called for premium meaning gasoline with the additive. I never knew of any other company that produced that additive. ---
**Author:** ![Johnny\_L.A](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johnny_l.a/32/1084_2.png) [@Johnny\_L.A](https://boards.straightdope.com/u/Johnny_L.A)\ **Post date:** [September 22, 2005, 4:16pm UTC](https://boards.straightdope.com/t/fill-er-up-with-ethyl/322886/5 "2005-09-22T16:16:53Z")
Fred: Aw, c’mon, Rick! Give me twenty dollars. Rick: Ayiyiyi. I can’t give you tenny dollars, Fred! Lucy says Little Ricky needs new shoes! Fred: I saw you at the gas station pumping Ethyl. I figure you _owe_ me twenty dollars! Rick: Fred, you’re too old to be a pimp! Fred: Gimme the twenty, or I’ll tell Lucy. Rick: Aiyiyiyiyi. ---
**Author:** ![Dr\_Paprika](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr_paprika/32/3042_2.png) [@Dr\_Paprika](https://boards.straightdope.com/u/Dr_Paprika)\ **Post date:** [September 22, 2005, 4:54pm UTC](https://boards.straightdope.com/t/fill-er-up-with-ethyl/322886/6 "2005-09-22T16:54:54Z")
Leaded gas reduced knock and boosted octane. However, lead is highly toxic and is not easily eliminated from the body – which is why tetraethyl lead is no longer used as a gasoline additive, and why lead solder was banned from cans in 1993. Lead (plumbum) has a long history in plumbing (note the similarity of the names) and some consider it a factor in the fall of the Roman Empire. The Ethyl company’s efforts over many years to quash reports regarding the toxicity of lead were not dissimilar to the high ethics of the tobacco industry. ---
**Author:** ![Fear\_Itself](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/fear_itself/32/19637_2.png) [@Fear\_Itself](https://boards.straightdope.com/u/Fear_Itself)\ **Post date:** [September 22, 2005, 5:28pm UTC](https://boards.straightdope.com/t/fill-er-up-with-ethyl/322886/7 "2005-09-22T17:28:43Z")
When leaded gas was introduced in the 20’s, they raised the price to cover the additive. When unleaded was introduced in the 70’s they raised the price again to take it out. They got us coming and going. ---
**Author:** ![minor7flat5](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/minor7flat5/32/258_2.png) [@minor7flat5](https://boards.straightdope.com/u/minor7flat5)\ **Post date:** [September 22, 2005, 8:13pm UTC](https://boards.straightdope.com/t/fill-er-up-with-ethyl/322886/8 "2005-09-22T20:13:35Z")
> [@Fear Itself](#): > > When leaded gas was introduced in the 20’s, they raised the price to cover the additive. When unleaded was introduced in the 70’s they raised the price again to take it out. They got us coming and going. On the surface, I’m with you on this one – it sounds like a premium-grade shafting. However, the reality is probably much different. They began using Tetraethyl Lead for a reason: the gasoline of the 20’s sucked. IIRC, TEL gave us a much needed edge in our fuel supply for our airplanes in WWII. I have a feeling that a modern car wouldn’t appreciate a load of 1920’s gasoline. That’s where the extra cost went in: how to make gasoline that had the same high octane rating while not using the bad stuff. ---
**Author:** ![Jeff\_Lichtman](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jeff_lichtman/32/1531_2.png) [@Jeff\_Lichtman](https://boards.straightdope.com/u/Jeff_Lichtman)\ **Post date:** [September 23, 2005, 7:12am UTC](https://boards.straightdope.com/t/fill-er-up-with-ethyl/322886/9 "2005-09-23T07:12:34Z")
> [@Dr\_Paprika](#): > > . . . lead is highly toxic and is not easily eliminated from the body – which is why tetraethyl lead is no longer used as a gasoline additive. . . Another reason is that lead ruins catalytic converters. There was a period of transition when gas stations sold both leaded and unleaded gas. To help prevent people from putting leaded gas into cars with catalytic converters, the standard size of the filler pipe and nozzle were made smaller for these cars. A leaded nozzle wouldn’t fit into a car requiring unleaded. When unleaded gas was new some people worried that it would damage older engines that were designed for leaded gas. I don’t know whether the concern was justified, but today people put unleaded in older cars and they seem to run okay (I guess). ---
**Author:** ![asterion](https://avatars.discourse-cdn.com/v4/letter/a/4da419/32.png) [@asterion](https://boards.straightdope.com/u/asterion)\ **Post date:** [September 23, 2005, 7:24am UTC](https://boards.straightdope.com/t/fill-er-up-with-ethyl/322886/10 "2005-09-23T07:24:18Z")
Well, there are lead substititues you can use, but not having a forty-year-old car, I don’t know if they’re needed or not. And I must say, while “If you run out of gas, get ethyl. If ethyl runs out, get Mabel,” was always funny, it’s even funnier now that I know the distinction. ---
**Author:** ![Airman\_Doors\_USAF](https://avatars.discourse-cdn.com/v4/letter/a/e36b37/32.png) [@Airman\_Doors\_USAF](https://boards.straightdope.com/u/Airman_Doors_USAF)\ **Post date:** [September 23, 2005, 12:38pm UTC](https://boards.straightdope.com/t/fill-er-up-with-ethyl/322886/11 "2005-09-23T12:38:46Z")
And yet another reason was to protect the valve seats in the valvetrain. Most cars from before the time of unleaded gas have to have their motor retrofitted for this problem or they have to run some sort of additive with every tank to ensure that they don’t damage their engines. > [@](#): > > But leaded petrol had even more benefits. As it burns, tetraethyl lead turns into a tan-coloured layer of lead oxide, which covers the valves and the combustion chamber. The valves hit hard against the valve seats several thousand times each minute. The lead oxide acts as a cushioning agent, and protects the valve and the valve seats. The lead oxide is also a lubricating agent. This reduces wear in the valve guides, as the valves slide inside them. > > If you start running your old leaded engine on unleaded petrol, the lead oxide quickly wears away. Damage begins, but only if your engine was made with “soft” metallurgy, and only in high-temperature areas - exhaust valves, exhaust valve guides and exhaust valve seats. > > At high temperatures, iron oxides form on a “soft” cast-iron valve seat. These oxides flake off and actually embed themselves (as hard nodules) in the “soft” face of the exhaust valve. These hard nodules work like tiny grinding wheels as the valve rotates. They grind away at the valve seat, making it recede into the head. At first, the valve-adjusting mechanism takes up the slack. Eventually, the adjustment is all used up, and the valve no longer closes completely. Then the edges of the valve quickly burn away - so you get what the mechanics call a “burnt valve”. [Cite](http://www.abc.net.au/science/k2/trek/4wd/lead2.htm)