alt Hacker NewsI want to wash my car. The car wash is 50 meters away. Should I walk or drive?
Comments
I'll be impressed when a LLM suggests that I get a 50m hose extension.
Kimi 2.5 nails it:
Walk. It's only about a minute away on foot, and driving such a short distance wastes gas and isn't great for your engine (it won't warm up properly).
*Wait*—if you're taking your car to the car wash, you'll obviously need to drive it there. In that case, yes, drive the 50 meters, even though it's barely worth shifting out of park.
One could argue that answers given by LLMs make sense. By assuming reasonability of the asking side, the answering side could assume that both options are possible and use abductive reasoning to conclude that the car to wash is already at the car wash station (and the question is about using another car to drive there).
Just saw a video of a guy asking chatGPT how to use an "upside-down cup", chatGPT is convinced it's a joke novelty item that can not be used.
If you asked that question to 100 random people on the street, I wonder how many would respond with 'walk'. Proper reasoning is not just a problem for LLMs.
Grok 4.1:
Drive.
50 meters is nothing — literally a 30-second walk or a 10-second drive — but the key point is: your car isn’t going to wash itself.
If you walk to the car wash, you arrive alone. The car stays parked at home, still dirty.
If you drive, the car actually gets to the car wash and gets cleaned.
So unless you’re planning to push the car the whole way (which is technically possible but ridiculous), the only practical option is to drive it there.
Bonus reality check: Driving 50 meters uses a tiny amount of fuel (maybe 0.005–0.01 liters in a normal car) and produces a negligible amount of emissions. Walking would be “greener,” but it literally doesn’t solve the problem.
Verdict: Get in the car, drive the 50 meters, wash it, and drive back.
You’ll have a clean car and still be home in under 5 minutes. Walking is for when you don’t need to move a 1.5-ton vehicle.
The responses most people are getting suggest that the LLM is failing to consider that to wash your car, it needs to come with you. But when I tried, it explicitly told me to "put it in neutral if safe, and gently roll it over while walking alongside". Pretty bizarre.
Opus 4.6: Drive. You'll need the car at the car wash.
I've seen Claude do similar stuff in code. I asked it to add a new API endpoint in a project. I specified it should use rx.java flowables as the framework I'm using has built in support. I specified to use micronaut data for the database connection.
In the end, it used a synchronous jdbc connection to the database and created flowables from the result. Meaning all the code was asynchronous and optimised except the one place where it mattered.
Took me about 3.5 seconds to fix though, so no biggie.
Grok 4.1 (which is fairly old in LLM terms, 4.2 release imminent)
"You should drive. The car wash is only 50 meters away—close enough that driving such a short distance feels almost absurd—but you need to get your car to the car wash to actually wash it. Walking there without the car defeats the entire purpose. Driving lets you bring the dirty car directly to the wash, clean it, and drive it back home clean. Walking would leave the car behind, still dirty. So yes, start the engine and drive the 50 meters. It's the only practical option."
Gemini thinking This is a classic "efficiency vs. logic" dilemma! Since the goal is to wash the car, you should drive. While 50 meters (about 165 feet) is a very short distance—usually less than a one-minute walk—it is unfortunately very difficult to wash a car that isn't actually at the car wash. Why Driving Wins: * Logistics: The car needs to be physically present for the high-pressure hoses or automated brushes to reach it. * Convenience: You’ll save yourself the confusion of the car wash staff when you show up on foot with a bucket and a hopeful expression. * The "Dry" Factor: If it's an automated wash, you get to stay inside where it's dry. When to Walk: * If you are just going there to buy a gift card or check their prices before bringing the car over. * If you're looking for a very brief bit of exercise before starting the chore. Verdict: Put the keys in the ignition. You'll be there in about 10 seconds! Would you like me to check the local weather to see if there's any rain forecast that might ruin your freshly cleaned car? s. logic" dilemma! Since the goal is to wash the car, you should drive. While 50 meters (about 165 feet) is a very short distance—usually less than a one-minute walk—it is unfortunately very difficult to wash a car that isn't actually at the car wash. Why Driving Wins: * Logistics: The car needs to be physically present for the high-pressure hoses or automated brushes to reach it. * Convenience: You’ll save yourself the confusion of the car wash staff when you show up on foot with a bucket and a hopeful expression. * The "Dry" Factor: If it's an automated wash, you get to stay inside where it's dry. When to Walk: * If you are just going there to buy a gift card or check their prices before bringing the car over. * If you're looking for a very brief bit of exercise before starting the chore. Verdict: Put the keys in the ignition. You'll be there in about 10 seconds! Would you like me to check the local weather to see if there's any rain forecast that might ruin your freshly cleaned car?
Depends on how long the hose is.
Someone suggested this follow up question to ChatGPT (which still exhbits this problem). The answer is even more non-sensical
> Will they have a 50m hose to reach my car once I get there?
Almost certainly not
Self-serve car washes usually have hoses in the 10–15 m (30–50 ft) range, mounted to a boom inside each bay. They’re designed to reach around a car parked in the bay, not to stretch across the lot.
What this means:
You can’t park 50 m away and spray from there.
You’ll need to pull the car into the wash bay.
Once inside, the hose easily reaches the whole vehicle.
So: walk over, drive the car the short distance into the bay, then wash.
(Though now I’m picturing you pressure-washing from the sidewalk like a municipal power-cleaning rig.)
I don't know who is dumber now... the AI, or the humans who keep interacting with them thinking that they actually possess some form of intelligence and are not just stochastically regurgitating a token stream.
I've used ChatGPT
Response:
Definitely by car
Even if it’s only 50 meters away, the whole point of a car wash is to wash the car, so taking it there on foot would be… complicated (and suspicious to the neighbors).
Now, seriously:
Distance: 50 meters is basically next door.
Time: by car it will literally take 10–15 seconds.
Effort: minimal.
Logic: the car needs to be there to be washed, so you have to drive it anyway.
The only reason to walk would be if you first want to check whether there’s a line or availability, and then come back for the car.
Pro tip: If you see it’s empty, take advantage immediately. Car washes tend to fill up quickly around midday.
Is it just an exterior wash, or interior as well?
How much of this reply is environmentalism baked into it with post-training?
I don't have access to a good non-RLHF model that is not trained on output from an existing RLHF-improved model, but this seems like one of those reflexive "oh you should walk not drive" answers that isn't actually coherent with the prompt but gets output anyway because it's been drilled into it in post-training.
Funny to read this after reading all the dismissive comments on https://news.ycombinator.com/item?id=47028923
Claude finished its list of reasons to walk with:
5. *Practical* - Your car will be at the car wash anyway when you arrive
???
ok I kind of disagree here with the assement, the models are actually intelligent enough to interpret "walk or drive" as the car ALREADY being there (otherwise why would you ask the question?? or having one of those pick up the car from carwash services), but they're also missing the context clue that "drive" means that their car is at their house - not the carwash.
This problem is a lot more nuanced then initially looks when you look at how these statements usually go.
Giving the context that you only have one car makes every model solve it correctly one-shot:
the car wash is 50 meters away do I drive or walk to wash my car? (I only have one car)
Walking is not practical if you need your car at the wash — you still have to drive it there anyway. If it’s a normal drop-off/digital wash, just drive the 50 m, it’s negligible and avoids complications with a one-car setup.
Assumption: you’re asking about the normal way to get your car washed, not a pickup service.
(5.3 codex spark)
Every recent model card for frontier models has shown that models are testing-aware.
Seems entirely plausible to me here that models correctly interpret these questions as attempts to discredit / shame the model. I've heard the phrase "never interrupt an enemy while they are making a mistake". Probably the models have as well.
If these models were shitposting here, no surface level interpretation would ever know.
Never ask an important question just once. Ask it in many ways, and on multiple models. If they don't agree at least you know you can't rely on these answers. For important questions I run 3-4 Deep Research reports (Claude, ChatGPT, Gemini, Perplexity) and then comparative analysis at the end.
How much of this is LLM reasoning and how much is training bias? I'm negatively surprised that nobody mentions this in the comments. Do you not remember black nazis LLMs used to generate? How can you all default to LLM being unreasonable and not understanding that a car needs to be driven as opposed to LLMs being trained with certain bias towards green agenda for example?
Mistral's Le Chat also fails spectacularly. Although interestingly it assumes that the "walk" option means you are carrying washing supplies back and forth in order to wash the car while it's parked at home. I wonder if the other models assume this is what you mean, IOW they may not know how a "car wash" normally operates.
"""
Great question! Here are a few things to consider:
If you walk: It’s only 50 meters, so it’s a very short distance—less than a minute on foot. You’ll avoid getting your car dirty again on the way to the car wash. It’s a quick way to stretch your legs and save a tiny bit of fuel.
If you drive: It’s so close that driving might feel unnecessary, but it could save you from carrying any supplies (like vacuum cleaners or cleaning products) back and forth. If the weather is bad (rain, extreme heat, etc.), driving might be more comfortable.
Verdict: Walking is probably the easiest and most practical choice for such a short distance, unless you have a specific reason to drive. What’s the weather like where you are? That might help decide!
"""
He left out Grok, who actually replies correctly :thinking:
Gemini 3 Flash is clearly a generation ahead of other LLMs, and as a result, it gave me the correct answer:
> Since your goal is to wash the car, you should drive.
> While 50 meters is a very short walking distance (roughly a 30-45 second walk), you cannot wash the car if it remains parked at your current location. To utilize the car wash facilities, the vehicle must be physically present at the site.
ChatGPt 5.2: “ Drive — because it’s your car that needs to get to the car wash.
50 meters is comically short, but walking there without the car doesn’t solve the “wash the car” part. If you’re worried about it feeling silly, you can also just roll/push it that distance if it’s safe and legal where you are, but the practical answer is: drive it over.”
Grok: “To wash your car at a car wash 50 meters away, you’ll need to drive it there—walking would leave the car behind, and I’m assuming you don’t have a really long hose or a team of helpers to carry it. That said, if you’re feeling extra eco-friendly (or just want the exercise), you could theoretically push it, but that’s probably more hassle than it’s worth for such a short distance. Drive safe!”
Claude Opus 4.6: “Drive. You need the car at the car wash. ”
I tested the latest flagship reasoning models (so the only models I use outside of coding for general questions):
- Opus 4.6 (Extended thinking): "Drive it! The whole point is to get the car to the car wash — you can't wash it if it's still in your driveway."
- Gemini Pro Deep Think: "You should definitely drive. Even though 50 meters is a very short distance, if you walk, your car will stay where it is—and it's pretty hard to use a car wash if you don't bring your car with you!"
- ChatGPT 5.2 Pro (Extended thinking): "You’ll need to drive the car—otherwise your car stays where it is and won’t get washed. That said, since it’s only ~50 m, the most sensible way to do it is often: 1. Walk over first (30–60 seconds) to check if it’s open, see the queue, confirm payment/how it works. 2. Then drive the car over only when you’re ready to pull into a bay/line."
A pretty reasonable answer by ChatGPT, althought it did take 2min4s to answer, compared to a few seconds by the other two models.
This question is straightforward for humans. I have run into a weird edge case like this in my actual life which confused me.
I'm in a band. After a concert, I have to drive back to the band room to drop off my instrument, then go to the pub for the post-concert drinks.
The wrinkle is I live about 5 minutes walk from the band room, and about 5 minutes walk from the pub (and it's about 5 minutes walk between the two). I can't carry my instrument on foot.
So...I have to drive to the band room. But if I then drive to the pub, I'd then have to drive home...two ridiculously short drives that make me sad. So I end up instead driving home, and then walking to the pub from there. Which seems weird...but less wrong somehow.
ChatGPT (free):
> I want to wash my car. The car wash is 50 meters away. Should I walk or drive?
Walk.
50 meters is a very short distance (≈30–40 seconds on foot). Driving would take longer [...]
Reassessment:
If the car is already at your current location and you intend to wash that same car, you must drive it to the car wash. Walking would not bring the vehicle there. [...]
Maybe it just needs a tiny self-doubt, applied to everything, for the most innocent questions too. I don't know.
All models getting this wrong is funny tho.
Yup, LLMs are not "artificial intelligence" - they just generate most probable token, until their authors hardcode functionality for specific community tests.
To mimic a real human, AI should be trained to laugh it off and ask - dude, are you joking? where is your car right now?
if the AI swallowed enough car detailing YouTube vids, it should answer neither, wash your own car with your own microfiber
So I'm not sure if anyone has tried this in the over 700 comments here, so apologies if it's been double-posted, but the rationale from ChatGPT almost makes me understand where it's coming from when you ask it to create an image of what it's thinking.
Here's the image: https://imgur.com/a/kQmo0jY
Here's the chat: https://chatgpt.com/share/69935336-6438-8002-995d-f26989d59a...
Still not really sure why you would need to get the water from the carwash next door, but maybe the soap quality is better?
MS Co-Pilot was so close.
If it’s a drive‑through wash where the car must be inside the machine, then of course you’ll need to drive it over. If it’s a hand wash or a place where you leave the car with staff, walking is the clear winner.
It still blows my mind that this technology can write code despite unable to pass simple logic tests.
Simple prompts which illicit incorrect responses from recent LLMs will get you on the front page of HN.
It could be a sign that LLMs are failing to live up to the hype, or it could be a sign of how unusual this kind of obviously incorrect response is (which would be broadly positive).
The only "satisfying" answer to that for me is: "This question doesn't seem to make sense, could you clarify ...".
My AI answer: https://ai.go-mizu.workers.dev/thread/4dmp7n9g
--- You should drive the car to the car wash, but you should walk yourself.
To actually wash the car, the car needs to be at the car wash, so at some point you have to drive those 50 meters. A sensible approach is:
- Drive the car the 50 meters to the wash bay. - Park or queue as required, then get out and do the wash. - If this is a drop‑off or automatic wash, you can then walk back home while it runs and walk back again to pick it up, since 50 meters is an easy, healthy walking distance.
tried Gemini 3 and it said to drive, even dropped a type of joke:
> The Verdict Drive it if you are using the car wash facilities (automatic, touchless, or self-serve bays). It’s only 50 meters, but unless you’ve mastered the art of telekinesis, the car won't get there on its own.
Ok folks, here is a different perspective. I used local model, GLM-4-0414-32b, a trashy IQ4_XS quant, and here what I got:
prompt #1:
> the car wash only 50 meters from my home. I want to get my car washed, should I drive or walk?
Walking is probably the better option!
Here's why:
Convenience: 50 meters is extremely short – only about 160 feet. You can likely walk there in less than a minute.
Efficiency: Driving involves getting your keys, unlocking the car, starting it, driving 50 meters, parking, locking it again, and then doing the reverse to get home. Walking skips all that.
Environmental Impact: You avoid using fuel for such a short distance.
Exercise: It's a quick little bit of physical activity.
prompt #2:
> the car wash only 50 meters from my home. I want to get my car washed, should I drive or walk? use long chain of thought thinking
8. Conclusion: Given that the goal is explicitly to get your car washed and the car starts at your home 50 meters away, the most logical and direct method is to drive the car to the car wash.
Walking does not move the car to the necessary location.
Driving, although a very short distance, is the only method presented that directly facilitates the core task of transporting the car to the wash.
The negligible time difference, minimal environmental impact, and directness make driving the car itself the clear choice for achieving the stated goal.
otoh, nanbeige-3B-Q8 (3 billion weights!) gave right away the following:
Drive.
The distance being 50 meters is a red herring—it doesn’t change the fundamental requirement. You need to move the car, and only driving accomplishes that.
If you meant something different by "drive or walk" (e.g., payment method, DIY vs. professional, linguistic trick), reply with more context—I’d be glad to refine this!
This is why no one should ask for advice of personal consequence from an LLM, yet.
Coding? absolutely. Coding advice? sure. Email language? fine. Health & relationships? hell no.
They're not ready for that yet.
Gemini 2.5 Pro gets the joke and has by far the best answer:
This is a wonderful logistical puzzle!
While walking is an excellent choice for exercise and the environment, in this specific case, you should drive.
Here's a breakdown of the two scenarios:
# Scenario 1: You Walk
1. You walk 50 meters to the car wash.
2. You arrive, feeling refreshed.
3. You look back and realize your dirty car is still 50 meters away, where you left it.
4. The car remains unwashed.
# Scenario 2: You Drive
1. You get in your car.
2. You drive for approximately 10-20 seconds.
3. You arrive at the car wash with the car.
4. The car gets washed.
Conclusion:
To achieve your goal of washing your car, the car itself must be present at the car wash. Therefore, driving is the only logical option.
Enjoy your sparkling clean car
As always when I see a post like this, I try to reproduce it, and have a completely different experience:
``` Q: I need to wash my car. The carwash is 50m away. Should I walk or drive? A: Drive — you need the car there anyway. ```
Gemini nailed this first time (on fast mode). Said it depends how you're washing your car, drive in necessitating taking the car, but a walk being better for checking the line length or chatting to the detailing guy.
Even the cheap and fast gemini-3-flash answers correctly. Post is clickbait
Results testing with 4 levels of Gemini (Fast, Thinking, Pro, Pro + Deep Think): https://ruby.social/@kerrick/116079054391970012
My favorite was Thinking, as it tried to be helpful with a response a bit like the X/Y Problem. Pro was my second favorite: terse, while still explaining why. Fast sounded like it was about to fail, and then did a change-up explaining a legitimate reason I may walk anyways. Pro + Deep Think was a bit sarcastic, actually.
Claude 4.6:
``` Drive. The car needs to be at the car wash. ```
Gemini Thinking gives me 3-4 options. Do X if you're going to wash yourself. Do Y if you're paying someone. Do Z if some other random thing it cooked up. And then asks me whether I want to check whether the weather in my city is nice today so that a wash doesn't get dirtied up by rain.
Funnily enough, both have the exact same personal preferences/instructions. Claude follows them almost all the time. Gemini has its own way of doing things, and doesn't respect my instructions.