Comment by pfranz | Hacker News Reader

Comment by pfranz | Hacker News Reader

It's funny that the article it references for the price hike says, "First off, yes sure it’s a bummer that prices are going up, but it’s still significantly cheaper than gas."[1]

They're also trying to compare NYC an LA Supercharger/electricity prices to "national average price" of gas including, "several regions seeing prices under $2 per gallon." Their comparison is $32-36 to fill up a 100kWh battery back versus 12 gallons at $2.85 for $34.20. I'm not really familiar with that class of car (or electric cars), but I'd assume anything comparable would take premium gas. I found a gas station in Westminster, CA (shown in one of the pics) and a local Chevron is currently charging $3.49 for regular and $3.69 for premium. The gas station I used to go to in LA that's only a few miles away is currently $3.09 for regular and $3.39 for premium. It would have been nice if they're going to make a comparison, try to do an honest apples-to-apples comparison.

The rate hike and how the cost compares to gasoline is worth noting, but the electrek.co article it linked to had much better information.

[1] https://electrek.co/2019/01/18/tesla-increases-supercharger-...

Yes, and it notes the supercharging “rates are significantly higher than what consumers in the same areas would pay at home,” which is actually where most people charge up. Super chargers are mainly for the occasional long distance trip. This doesn’t really support the conclusion of the article that calls into question Tesla’s TCO math. Most people are not doing the bulk of their charging on superchargers.

No car requires premium gas anymore.

High compression ratio / turbo gas engines definitively do. Try pushing a BMW M3 ( competition for the model 3 perf ) on 87 and you’ll see how long the engine lasts.

Look up engine knock.

It'll work just fine, it will however not run at full power.

Just about every modern car comes with knock sensors and computer controlled knock prevention mechanisms that will compensate for lower octane, especially on high strung, direct injected, twin-turbo cars like a BMW M3. The only real downside is increased emissions for using non-optimal fuel and lower engine efficiency/power.

It lasts just fine (Source: I've done it)

The M3 has knock sensors, like everyone else.

https://www.google.com/search?q=bmw+m3+knock+sensor

If you look up engine knock on wikipedia, it will tell you the same

From: https://en.wikipedia.org/wiki/Engine_knocking#Knock_detectio...

"Due to the large variation in fuel quality, a large number of engines now contain mechanisms to detect knocking and adjust timing or boost pressure accordingly in order to offer improved performance on high octane fuels while reducing the risk of engine damage caused by knock while running on low octane fuels. "

"...while reducing the risk of engine damage caused by knock while running on low octane fuels."

That doesn't necessarily mean it reduces the risk of engine damage to zero. The engine still has to knock for the sensors to detect it and adjust unless it uses flex fuel sensors. Yes modern engines CAN cope with lower octane fuel than they were designed to use, but you would lose performance and run an increased risk of damage. If the manufacturer states a minimum octane rating you would likely be voiding some parts of your engine warranty by running the incorrect fuel.

It will last at least as long as the warranty.

Cars in the US are required to be able to run on 87.

Look up engine knock sensor.

Not sure why you are getting downvoted. I'm not aware of any modern car that requires premium fuel in practice. All have knock sensors/etc.

You will just end up losing some fuel efficiency or power.

I imagine they're getting downvoted because, while it's technically true in the short-term, it's a terrible idea. If you're trying to do an apples-to-apples comparison between electric and gas, unless you're going to measure and calculate the fuel efficiency loss, it makes no sense here.

If you're paying for a higher-end car, it makes no sense to cheap out $.30/gal. Fuel costs, especially the difference from regular to premium octane, are so little in relation to everything else. While anti-knock sensors should avoid short-term damage, the long term effects aren't known [1].

[1] https://jalopnik.com/why-putting-regular-gas-into-a-car-that...

I'm sorry, but this is just a ridiculous comment and terrible advice. I was driving a borrowed Mercedes over Christmas purchased earlier that year. When I filled it with gas it clearly said, "minimum octane rating 91." Sure, you can use regular gas and on any modern car it shouldn't cause damage, but it's silly to pay that much for a car and cheap out $.20-$.30 per gallon when it is designed and recommended for it.

I included the cost of regular gas because even that showed the article was being disingenuous about cost even using those numbers.

Per a 2017 jalopnik article[1], any short term gains by using cheaper gas are likely to be lost because of decreased performance. While any short-term problems will likely be addressed by anti-knock sensors, long term problems aren't known. If you're that price-sensitive, buy a car designed for regular octane fuel.

[1] https://jalopnik.com/why-putting-regular-gas-into-a-car-that...

TIL that in the US you use a different octane rating to the UK (and Europe generally). We use RON, while you use an average of RON and MON (called PON or AKI).

Our baseline fuel here is called "Premium Unleaded", despite it being the standard fuel and is 95 RON, which should equate to about 90-91 AKI meaning it lines up with your Premium gas.

We also have "Super Unleaded" at the pumps, which is 98 RON and should equate to 93 AKI in the US.

I guess that means we have no equivalent of your regular gas.

FWIW I've never managed to detect any benefit of using the 98 octane fuel, either in performance or fuel consumption. I've never owned a really high performance car, beyond a tweaked Saab 9000 Turbo running a higher boost, and that seemed to be happier on the Premium. I always assume that the 98 octane stuff is just a way of extracting extra money from gullible people, but I have no more proof of that than the anecdata from all the people who buy it and swear by it (probably because of https://en.wikipedia.org/wiki/Choice-supportive_bias )

Reply on news.ycombinator.com