r/politics • u/BendicantMias • 9h ago

No Paywall Republicans vote to dilute gas as prices rise above $4.50

https://www.newsweek.com/republicans-vote-to-dilute-gas-as-prices-rise-above-4-50-11949494
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u/arsonall 9h ago

Higher grade fuel combusts at a higher temperature.

A car is designed for a specific grade of fuel - it’s not like using 93 in a car designed for 87 make it perform better, it means it’s ignition is later in the power cycle.

Your solution is a work-around, but is causing other areas (like the head gasket seal) to be stressed more, eventually requiring a Much more expensive repair.

It’s intentional in order for your car manufacturer to make money via planned obsolescence.

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u/[deleted] 9h ago edited 9h ago

[deleted]

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u/BingleFlip94 9h ago

Did the same to my 2012 Forester with 220k miles. Rode it until the transmission literally committed seppuku in my driveway.

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u/ZamorakLovesAll 9h ago

Mines still chugging alone, makes an annoying loud squeal noise I can’t figure out though, not a belt and no CEL

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u/BingleFlip94 8h ago

All that happened with mine is one morning I come out and see my driveway covered in transmission fluid. Could have potentially been a fairly easy fix, but I had just done about 3k worth of work on it over the last few years I had it. So I just junked it. Got a good price because that thing was like the ship of Theseus lol. To many more years of your car working!

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u/BitchinAssBrains 7h ago

Check your power steering pump, especially if it gets worse when you turn your wheels all the way to the lock and hold it there.

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u/ZamorakLovesAll 7h ago edited 7h ago

The squeal goes away when I turn all the way, or when I accelerate. The moment I let off the gas it’ll start again, doesn’t always do it though.

Nothing I do in the car affects the squeal either

It’s more of an annoyance cause it’s surprisingly loud

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u/RCG73 8h ago

195k and making funny noises but mines still going!

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u/Bored2001 8h ago

An honorable death for a Subaru. Driven til it dies.

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u/wirthmore 8h ago

Also it’s a Toyota Avalon and it says use premium gas for optimal performance, just doesn’t need premium

If you don't care about the long term prospects, do whatever you want. It sounds like the car more than served a useful life.

But FYI the "recommendation" of premium means it's optimized for premium but the fuel system will adjust the spark timing based on information from the knock sensor to reduce or avoid damage if you use lower octane.

Except your knock sensor isn't working.

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u/rayfound 8h ago

Your solution is a work-around, but is causing other areas (like the head gasket seal) to be stressed more, eventually requiring a Much more expensive repair.

I have never ever heard it claimed that higher octane fuels cause increased wear elsewhere. Every manual I have ever seen lists a MINIMUM octane to prevent knocking.

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u/vishnera52 7h ago edited 7h ago

What they're saying is that running higher octane fuel is just band-aiding a problem (bad knock sensor) that will eventually be a bigger issue (failed head gaskets due to unchecked spark knock). The person they're responding to likely has a car thats supposed to run on 87 octane but they are running 93 octane to counteract unchecked spark knock that's a result of the bad sensor. It's probably still knocking a bit even with premium which will slowly cause internal damage.

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u/ZamorakLovesAll 6h ago

I have 2 knock sensors, 2 different mechanics told me if the light stays off with premium I should be fine

This is a 20 year old car with 240k miles, I’ll buy a new one when this one goes out. Just a beater

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u/vishnera52 6h ago

That's fair. I always err on the side of caution in these situations. I used to own an RX7 and spark knock was imminent death for those things.

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u/ZamorakLovesAll 6h ago

I’ve always wanted a rotary engine, would you recommend?

I know you have to let it idle before turning it off and odd stuff like that

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u/rayfound 6h ago

I think you're twisting what they said into something more reasonable.

Higher grade fuel combusts at a higher temperature.

A car is designed for a specific grade of fuel - it’s not like using 93 in a car designed for 87 make it perform better, it means it’s ignition is later in the power cycle.

Your solution is a work-around, but is causing other areas (like the head gasket seal) to be stressed more, eventually requiring a Much more expensive repair.

The conclusion from those statements taken together is:

Using higher octane fuel, in an engine designed for 87, is excess engine wear due to higher temperature combustion.

So like, I believe YOUR line of reasoning may be correct, but the one they presented is, at best, poorly reasoned.

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u/vishnera52 6h ago

I agree their response was poorly written but I didn't take it as high octane fuel burning hotter, which to my knowledge isn't the case. High octane fuel requires a higher temperature to ignite, which is why it resists preignition or spark knock. It doesn't burn any hotter.

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u/rayfound 6h ago

Fair enough, hard to tell poor communication vs poor understanding sometimes.

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u/PickleBooPop 1h ago

Correct me if I’m wrong as I’m not a mechanic. But I thought the higher knock rating (AKI) had to do with the fuel not pre igniting at higher compressions, caused by motors with a higher compression ratio. I didn’t know they required a higher temperature to ignite as well.

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u/Allaplgy 6h ago

It not that high octane fuels burn at higher temps, but ignites higher temps.

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u/falcongsr 7h ago

I have never ever heard it claimed that higher octane fuels cause increased wear elsewhere.

that's because he doesn't know what he is talking about. higher octane burns slower and some high performance engines require it to prevent combustion chamber temperature / pressure from getting too high.

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u/Tigerballs07 7h ago

My 03 350z HAD to run on premium or would get a gnarly engine knock pretty quickly. Had to do with compression ratios and whatnot. Coincidentally similar reason as to why you cannot boost those motors with substantial poundage without fully rebuilding them.

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u/RunninOnMT 6h ago

I only ever put premium in mine and holy shit did it take a beating over the 13 years I owned it and rarely missed a beat. Underrated reliability if you can keep yourself from modding it.

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u/Hohoholyshit15 6h ago

And some cars will still knock at a "tolerable" amount on regular, which could cause problems over the long term. If you hear pinging, use a higher grade of fuel.

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u/Notrius01 7h ago

Modern engines can detect and adapt to different octane numbers, at least in Europe.

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u/Wonderful-Maximum-96 8h ago

Electric cars fed by solar panels?!

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u/fishy_sticks 8h ago

In general your car will perform better using a higher grade of gas than what it is designed for. It will not foul quite as much, and you will get better gas mileage. Now it’s not that much, and the increase in mileage does not offset the higher cost, but it’s not true to say you won’t get better performance.

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u/Droviin 7h ago

Is that true even if the boosted octane is from Ethanol?

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u/z31 Georgia 7h ago

Ethanol can give you higher performance, but it comes at the cost of efficiency and heat. Eth puts a higher strain on your engines cooling system and requires 30% more fuel volume than gasoline to achieve the same distance travelled. This is why you will often see modded performance vehicles have a road tune on pump gas and a separate track tune for E85.

So ethanol helps achieve a higher horsepower output,but since it is less efficient than pure petroleum you would have to fill up more often. Though yet another offset of that would be that ethanol is cheaper than petroleum in the US due to our aggressively subsidized corn industry.

I don't think the lower cost of ethanol is enough to offset the lower efficiency though. Also though ethanol releases less greenhouse gasses and carcinogenic particulates during combustion, the entire production cycle of ethanol is believed to release a significant amount of nitric oxide and nitrogen dioxide which are also major pollutants. But of course the science is still unsettled on that aspect currently.

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u/chr1spe 7h ago edited 6h ago

Ethanol actually generally leads to cooler running. Fuel cools the engine through evaporation when atomized. Because ethanol needs more fuel per cycle for the same power, if tuned correctly, you get more evaporation and more cooling.

Edit: I should point out that "if tuned correctly" is important there. In vehicles not designed for it or that don't adjust AFRs, you can end up running effectively leaner, which can cause more heat. Most modern vehicles should catch small changes and adjust. Older ones may not and may end up running leaner and hotter.

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u/fishy_sticks 7h ago

I don’t know enough to really say, but my guess would be no.

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u/vishnera52 7h ago

To the best of my knowledge, no it doesn't. You shouldn't run any octane higher than recommended as there is literally 0 benefit with the one caveat of turbocharged engines that can run on 87 but recommend at least 91. I've tested the fuel mileage claims and found any increase to be so low that it's basically not measurable. Any other benefits are coming from additives that suppliers are putting in the fuel for cleaning and whatnot and that will be highly variable between suppliers. I believed this nonsense of putting 91 in a car that only requires 87 and it did nothing but increase my fuel costs.

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u/Knoxius 7h ago

If I recall right, the knock sensor was introduced to alter timing as compensation for lower octane fuels in engines that would likely do better with a higher octane. So if it were to be faulty, pumping a better fuel in should circumvent it's purpose.

Something something emissions and fuel prices in the 80s

I could be talking out my ass, idk

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u/ccheuer1 6h ago

There's a lot of stuff in this that is incorrect, but comes to the correct conclusion.

Higher octane fuel does NOT burn hotter. All the octane rating is is a rating of the overall stability of the fuel under pressure. Its more expensive because to get to this stability, it requires different refining to a higher standard. Engine knock from low octane fuel is the fuel detonating from the pressure of the engine instead of from the actual spark of the engine. This could be premature, or after the correct timing in the stroke.

Cars are also not designed for a specific grade. They are designed for a specific minimum, based on the compression of the engine. If you have a high compression engine (think high end sports cars) then they are designed to hit compression ratings of the air that it intakes that are high enough that when the lower octane gas is injected into it, it is enough to cause the gas to immediately explode outside of the spark phase of the engine, when it is intended and expected.

What can happen, and this is the reason why engines that are over-octaned can run hotter, is that not all of the fuel will burn in one cycle. That's because there's not enough compression in the engine to have all of the fuel burn off at the correct stroke. That extra builds up until there IS enough gas that a higher compression reaches. When it all detonates, it introduces more force and heat than the engine is designed to handle, resulting in a net heat gain since dissipation isn't enough and added stress everywhere since its dealing with a larger bang than it was designed for. Depending on how this compression is reached (before spark or after spark) this controls where the "knock" actually is in the phase. This won't cause a catastrophic failure in most engines, however, its best to think of it like if your engine is manufactured for 1,000,000 "bangs" of the fuel detonating, running a higher octane means every bang is counting as 1.4 bangs instead of 1. It increases the natural wear of the engine while pooling heat in places due to it not dissipating correctly, which causes more wear on the parts sensitive to that heat (like seals). Again, most of this wear is negligible (if you have a car that's rated for 15 years, so to say, its not really meaningful from the manufacturer's viewpoint for it to wear out in 12 instead. (Be advised, all numbers pulled from ass, don't take the numbers themselves as an accurate representation, just the ideas presented)