←back to thread

152 points voisin | 4 comments | | HN request time: 0.844s | source
Show context
bane ◴[] No.42174985[source]
I can't believe that the average price of a car in the U.S. is almost $50k. For rapidly depreciating assets.

Here I am working out TCO costs for a range of mid-sized cars for my next purchase, and trying to decide if the extra $2k for a Prius Prime over a Prius will beat the differential in fuel costs for my driving situation. I feel like a chump, but I know it's the smarter thing to do with my money.

I coworker of mine just spent $100k on a regular old pickup truck that is planned to spend less than 5% of the time doing anything other than commuting him back and forth to work. It doesn't fit in any of the parking garages around here, or in his garage -- he has to park it at the other side of a surface lot because it doesn't fit in the normal spots. It gets like 11 mpg and uses the 92 octane fuel.

Americans won't buy cheap cars, they won't buy upmarket small cars, but they'll burn their children's college fund into the ground for a 2 second gain on 0-60 and bad ergonomics.

I can afford the fancy car, but I'd rather turn $100k into $200k in my index funds and buy an entire apartment in Spain overlooking the Mediterranean with the gains.

We can have nice things, but this is why we can't have affordable things.

replies(10): >>42175111 #>>42175381 #>>42175860 #>>42176520 #>>42177240 #>>42177408 #>>42178830 #>>42180551 #>>42182689 #>>42187225 #
jgalt212 ◴[] No.42182689[source]
> uses the 92 octane fuel

There's no evidence that higher octane fuel is required or leads to performance gains in excess of the cost bump.

replies(1): >>42183039 #
sojournerc ◴[] No.42183039[source]
High compression engines require high octane to avoid knock. It's not about performance. An engine with a turbo or super charger will always need higher octane fuel.
replies(2): >>42183304 #>>42186624 #
jgalt212 ◴[] No.42183304[source]
I have yet to see a study showing efficiency gains, or losses, are greater than the price difference in fuel types.
replies(2): >>42183472 #>>42183731 #
1. sojournerc ◴[] No.42183472[source]
As I said. It's not about efficiency.

Knock (pre-ignition) will destroy an engine. I have a naturally aspirated infinity, but with compression ratio around 13:1 it calls for premium.

Believe me I wouldn't pay for it if it wasn't necessary. It's still cheaper than a new engine.

replies(1): >>42183687 #
2. jgalt212 ◴[] No.42183687[source]
Knocking and engine efficiency are inter-related.

That being said, unless you are constantly flooring the accelerator and / or doing a lot of track driving, it seems challenging to make a modern (and properly functioning) engine knock on a persistent basis (irrespective of octane).

replies(2): >>42186248 #>>42186668 #
3. cactacea ◴[] No.42186248[source]
This is a weird hill to die on man. Modern ECUs are smart enough to tune the timings in to prevent knock when the wrong fuel is used, at the cost of both efficiency and fuel economy. "Runs" is not the same thing as "runs well"
4. EricE ◴[] No.42186668[source]
Are you familiar with Boyle's Law? You compress a gas and it heats? Higher compression of air/fuel lowers the detonation point. If your air/fuel mixture detonates at the wrong time in an engine, you will get damage. Higher octane fuels take higher temperatures to detonate.

That's why higher compression engines REQUIRE higher octane fuel, as the manufacturer will specify. Run without it, damage your engine and try to make a warranty claim. Good luck with that!