Can’t drive but family needs car - how much should I pay towards it?

[Jeffjefftyjeff]

Any advice welcome.
I don’t drive and pay weekly bus pass. DP has car and drives 50 mile round trip to work every day. We need a car for ferrying DS about (football mainly, he walks a lot of places) and shopping etc. (Very) Occasionally DP gives me lifts too. I am happy to pay a proportion of it but how do we best calculate how much?

Other info in case relevant: we have separate bank accounts but put funds for household expenses in joint account based on proportion of our income. Currently all of car cones out of DPs personal account. I earn more than DP. He likes gas guzzling cars (but is willing to get cheap run around instead).

Geez... are you a family or friends that house share? You have a child for goodness sake!

Each of you increase the amount you put into joint funds proportionately to your income, then pay for the car and the bus pass out of that

This.

What a pointless dilemma.. you have a joint account. Scrap your solo accounts and both use your joint account.
presumably you plan to be together as a couple as you have already started a family together 🙄 all the separate money and accounts etc does not show commitment to one another.. so the opposite really.

FWIW, we have a car and DH doesn't drive - gets the bus to work (and I get the train). Our travel - including running the car - is all a household expense, so it comes out of household funds (including petrol). Our set up financially is a bit different though; we pool everything and then split what's left between the two of us equally as 'play money'.

We have separate accounts, but I can honestly say I've never thought like the OP. It's a household bill, something for your family to benefit from.