Would you expect an offer of petrol money in this instance?

Yes, or bought lunch etc.

Most people? Where are you getting that from, in all my many years of being a driver I can't remember ever being offered petrol money and I've given lifts to lots of people

Maybe they are all outliers but that doesnt seem likely

Depends.
Do you generally take turns to drive ? - No
Do one person always drive? - Yes

Did passenger pay for parking / buy lunch ? - No
Otherwise - Maybe

Were they already going anyway, regardless of if friend(s) jump in or not ? - depends a bit.

How long is the friendship? Does passenger friend contribute to the friendship in different ways ?

Are any of the friends temporarily going through a time when they are skint, or a time when one is feeling quite flush ?

It depends really - if we were travelling together to save costs or they weren't close friends maybe but if it was my bestie and I was going anyway then no, but my friends will generally buy my soft drinks, pay for dinner or return the favour next time.

i think it depends on your relationship with the friends,is one where these things are reciprocated and turns taken ?
I have friends where offerring a contribution to fuel cost would be fine as im the one who drives and they never do and friends where we take it in turns and dont reimburse as its fair.

No I’d pay for parking though or some thing but yeah with friends it always evens out. With acquaintances and if it was just a convenience and doing a favour I would pay cash.

Yes, I offered petrol money someone recently when she drove us both fifteen miles and back (thirty in total) for a one-off trip. It’s not just the petrol cost (and wear and tear) , but a gesture of thanks for the driving.

No.

45 min ish drive to do something and then 45min ish back? Nope.

Sometimes I drive, sometimes they do.

Now if we were driving from London to Scotland for our holiday, then sure, that's different. But even then it would be "I'll get the grocery delivery/dinner whatever [insert stuff of roughly same cost] when we get there coz you drove"

It seems perfectly normal to me. What bit do you think is weird?

Not at all

That’s so weird.

Not for 80 miles, my car does around 400 miles per tank and a tank costs about £65 I'm not asking my friend to split £12 3 ways. It would be nice to be bought a coffee but not expected, to the extent of notice and think of that was really thoughtful of them

No, I’d just accept a coffee or something if they offered. I don’t think I’ve given/been given petrol money since I was a teenager!

I’d offer. If they declined I’d make sure to get them coffee or something while away.

No. I'd only accept petrol money if I was giving someone a lift that was long distance and of no benefit to me.

One of my friend's always drives when we meet up even though I offer to each time. She does have a more luxurious car than me though so I think she prefers we go in hers.

Even though its normally local places we go, I always buy lunch or coffee and cake as a thank you for ferrying me about.

I’d get the coffees or the first drink in, but honestly my friends would laugh if I offered them a fiver for petrol, as would I (not wealthy at all). Depends on the context though, if you’re all struggling students it changes things.

In my friend group we wouldn't offer money because none of us would ever accept it but we'd cover lunch or something for the driver. Offering nothing is bad manners.

It wouldn’t occur to me to offer money for petrol for a one off shortish trip like that, no. But I would want to buy them lunch or a coffee as a thank you for the effort of driving me.

Different if it was, say, a week long road trip from London to the Highlands and back or similar - then id expect we’d take turns to pay to fill up the car.

It depends on your custom and practice of sharing lifts and outing expenses.

Most people would offer the driver £5.00 based on say £14.00 petrol costs.

This, absolutely. Once was asked to give a friend of a friend a lift - a 3 hour drive in each direction. Not only did he not offer petrol money (which I wouldn’t have taken) he went out of his way not to be in the drinks queue at the same time so didnt offer to buy me a drink as a thank you. He’s never getting a lift from me again.

No. Generally in those circumstances among my friends we'd find something else we could pay for e.g. the parking, lunch or coffees along the way to redress the balance, but a direct offer of petrol money, no.

This.

I would offer a contribution to petrol and usually it gets refused so will make sure that I treat the driver to lunch etc

If it was somewhere I was going anyway then no. Oddly enough I would always offer though. Are the friends drivers, I often find that people who don’t drive don’t consider the costs associated with running a car so wouldn’t think to offer.