‘By car’ and ‘in the car’ aren’t always interchangeable, are they?

I won't speak on the grammar, but none of these sound natural with "in the car", only "by car" to me in American English. "by car" to me implies that you are using it, and all of these are talking about travel. "in the car" to me doesn't always imply that, you could just be sitting in a parked car or something. like saying "where is John?" "He is in the car" - this would also be incorrect if you said "he is by car".

In the examples you have here I think "in the car" would be acceptable, but "by car" is better.

you would use “by car” in all of those scenarios. “in the car” just refers to location. “i left my jacket in the car” or “the kids are already in the car.”

>1. It takes me about 30 minutes by car/in the car. >2. It's 20 minutes by car/in the car. >3. 15-20 minutes on foot or a few minutes by car/ in the car. >4. I go there by car/in the car. >5. The nearest grocery store is 3 minutes away by car/in the car. all of these sentences sound totally fine with "by car." I wouldn't use "in the car" for any of them. but if I were actually saying any of this in real life, I (an American speaker) would almost always use the word "drive." saying "by car" sounds oddly formal to me. It's about a 30 minute drive. It's a 20 minute drive. I drive there. 15-20 minutes on foot or a few minutes driving. The nearest grocery store is a 3 minute drive away.

In these situations that are interchangable. A situation where they wouldn't be would be something like: >We sat in the car waiting for hours for my dad to finally be ready to leave. You can't switch it out if it's just a description of location, only if it's a description of method of travel.

In American English, "by car" sounds more natural, but I think it would be even more natural to change the sentence to use the word drive or driving. For example, I drive there. Or The nearest grocery store is a 3 minute drive.

They are interchangeable in all your examples in British English.

We (USA) would normally just say “driving” or “commuting” or “traveling” because in the USA almost all daily travel is by car/truck/suv, and/or motorcycle. Some bicycle and some do employ other methods of travel, especially in larger cities that have trains, subways and buses or light rail for daily use.  1. It takes me about 30 minutes to drive there. (Car, etc.) 1a. It takes me about 30 minutes to ride there. Could mean public transit but more likely means a bike: motor (gas, electric) or manual push. 2. It takes 20 minutes to get there. (Personal vehicle implied, though could also mean public transport if it’s zippy enough and in certain locales) 3. 15-20 minutes on foot or a few minutes’ drive. 4. I drive there. 5. The nearest grocery store is 3 minutes away when I drive. 5a. The nearest grocery store is a 10 minute walk but it’s 3 minutes when I take my car. Takeaways: there are a number of ways to communicate and some choose casual methods and some choose formal methods. Some English speakers do code switching and change to a cultural dialect when among friends and family. I tend to speak more formally than many of my friends and even colleagues at work. However, there are times when it’s easier to be less formal. How far is the nearest grocery store from my home? 5 minutes. (Driving implied.) It’s a 5-minute drive. It’s not safe to walk where I live.

You would use “by car” in all those scenarios. An example of in the car would be “I left my homework in the car” or “have you put your school supplies in the car?”

All alternatives are grammatically correct, but "in the car" implies that you are travelling in your own car. For example, if your neighbour gave you a lift to the shops in their car, it would be correct to say, "I went to the shops by car.", but not, "I went to the shops in the car."

Where? In the car. How? By car

Ive read the word "car" too many times in yhese comments and now it doesnt make sense🤣

I would only use "in the car" for describing something or somebody who is physically inside a car. I am sitting in the car. My bag is in the car. For describing a journey made using a car, it is always "by car". For all of the examples, "by car" would be the usual way to say it.

As said by most commenters both are possible "by car" is probably more used. "in the car" is more likely if you have previously been talking about a particular car. In these cases the car itself has a higher importance in the sentence. "I'm so happy I have a new car. It used to take me an hour to get to work. In the car, I can do it in 5 minutes." Notice that "in the car" has moved to the beginning of the sentence as the speaker is making a point about the car and thus it's considered the important part of the sentence.

In most of these sentences, **"by car"** sounds more natural because you're talking about the *method* of transportation. **"In the car"** works better when you're specifically talking about being inside the car (like "We talked *in the car*"). For example: * ✅ *"It takes me about 30 minutes by car."* (method) * ✅ *"We listened to music in the car."* (inside the vehicle) That said, in casual speech, some people might say *"in the car"* for time/distance (like your grocery store example), but *"by car"* is clearer.

Adding onto what others have said, "in the car" doesn't really sound natural for any of these. The only scenario where it would sound natural would be getting asked by your spouse or someone you shared a car with "How did you get to work yesterday?" and you responded with "I went in the car." Even then, it's a rare thing to hear or say, and you'd never say the same with an indefinite article or about a vehicle that wasn't shared. "I went in a car" in reference to driving rather than being inside a car is simply unheard of you'd always say "I took a car" or "I drove." These turns of phrase are also not interchangeable with "by car," which implies a sort of impersonal almost systemic framework to the situation in American English, e.g. "What's the fastest way to get there? By car or by train?"

I would say by car feels slightly more natural, but in the car is perfectly fine. I'm British English, but I now live in America, so my slight preference might be affected by that. Looks like it depends mlom the specific dialect.

As a Brit, I cannot think of a time I would ever say by car instead of in the car ofc aside from if i was referring to travelling in a generic car rather than ‘the car’ (the car i normally drive)

“By car” is better, but as others have suggested, in American English, it’d be unlikely to hear any of those concepts structured that way in a phrase. I’d expect: 1. It’s a thirty minute drive, for me. 2. It’s a twenty minute drive. 3. It’s a fifteen to twenty minute walk, but the drive’s only a few minutes. 4. I drive there. 5. The nearest grocery store’s a three minute drive. That’s how I’d expect to hear these concepts phrased in informal speech. You *can* say “by car,” and probably wouldn’t raise too many eyebrows, but it sounds a little formal or impersonal. The “by car” answers sound like something one would say during a deposition of some kind, or something.

Another potential meaning that I haven't seen discussed is that in addition to it's use as a verb (where by car means using the car to travel), by can also refer to location in much the same way as in the car, however it would be extremely uncommon to use "by car" to refer to location without specifying which car. When used to refer to location, by means adjacent to, while in reverse to being inside of the location. To give an example, you might say Bob is standing by his/the/that car, but it would be very strange to say Bob is standing by car because "by car" would usually be a verb and even if you interpret it as a location it would be too vague to be a meaningful statement.

Yeah they are all fine although 'I go there...' is an unnatural construction regardless of what you end it with.

Those are all interchangable in NZ English (caveat, a long time in the US, so some word choice infection; the other day I said "look at the trash on the sidewalk" and almost died.).

As you can see from the comments, this is a dialect difference. "By car" is the consistent use in US English. "In the car" is more common in the UK, NZ, or Australia; although "by car" is still understood perfectly well. I'll leave you to draw your own conclusions about which group are insisting that theirs is the *only* correct form, and why that might be.

“By car” could be used in all five. I personally would only consider numbers 1-3 to still be completely correct if “in the car” is used, but since my English is influenced by the Hibernian dialect others might not consider it to be correct in those contexts.

Apparently, "in the car" is unobjectionable in British English, but in American English, it is definitely "by car". So it depends on who your audience is.

Those would all be interchangeable where I'm from. The only difference is you'd specifically say "in the car" to explain where a person or item is located. (I found my umbrella; it was in the car.)

Any of those are understandable in conversation, but "by car" when talking about a method of travel is more correct. When you say "in the car" you're talking about literally sitting in a car. Then, with context, we realize you mean driving or being driven.

British English speaker here. They all sound fine to me and I would say they are completely interchangeable. 

Anytime you can use “by car”, you could also use “in the car” and the sentence remains grammatical. However, the meaning might change. “By car” is a combination of both in the car and in a car. It doesn’t differentiate. By car just means “car” it gives no indication of which car. I went to the shops by car. [a car, maybe mine maybe yours , but who knows?] I went to the shops in the car. [the specific car we normally use] I went to the shops in a car. [not our usual car]

When you want to describe the method of travel, use “by car”. When you want to specify the location, use “in the car”. All of your examples seem, to me, to be primarily about method of transportation not the specific location. I prefer “by car” for all of these. That said, “in the car” would be grammatically fine and understandable for each—just they would sound less expected to my ear. Of your examples, I find number 1 the most interchangeable between both options and I think numbers 3 or 5 are the ones where I would dislike “in the car” most.

All of those sound weird with "in the car". It's not something I'd say or ever recall hearing. "In the car" means physically inside the car. "By car" refers to mode of transportation. It's like saying "It's 10 minutes on your feet" rather than "10 minutes by foot". Sure I suppose it's correct but still sounds extremely strange.