Nononono

Don't do this. You're thinking in the right direction though.

If the receptacle is only rated for 20 Amp even though the wire is over sized, you breaker for the lowest rated component. In this case, the the receptacle.

Use a 20a breaker.

As far as connecting the receptacle, use a 12 gauge pigtail. It's not rated for 8awg

You've almost got it right. Run heavy cable. But only put a breaker on it that matches the weakest component: the plug.

If you do it with only 1 set of wires, you will mess up charger later if the single gang plug is used at same time.

Run the amp rating wire you want for charger, and run a separate 12 ga wire on separate breaker for plug.

You may want to research the ev charger as they are beginning to offer larger amp systems for quicker charging.

Or I think I need to add a panel at the carport with individual breakers for charger and plug once I add a charger it seems?

You can have faster EV charging but do you really need to super charge your car at home quickly? A 50a will charge all EV cars overnight which is what you’re really looking for.

Electrician here. If you are planning to add a 48a EV charger, you need to understand that an EV charger is considered a 'continuous' load. Meaning you need to treat it as being 1.25x the rated load: eg 48 x 1.25 = 60a. This needs #6 wire, not #8.

And for the cost, I would look at running an aluminum acwu armoured cable to the garage for a 100a subpanel. Where I'm at, practically the same cost as running #6 or #8 3 conductor in a conduit. Then, off the sub-panel, you can run lights, outlets, EV, etc. Gives you more flexibility down the line. Just be sure to treat your terminations with anti-oxidant if you go aluminum, and ensure your panel lugs are rated for aluminum conductors (most are).

I'm in Canada, so I'm trying not to go too much into code rules, because they're different up here, but the continuous load stuff is for sure the same. Check with a local licensed electrician for any specific questions you might have.

I’d check with some local electricians first before you do anything. A fast charging station is a fairly considerable load, and they might not go near anything you did yourself and can’t show permits and inspections for.

I would think by code, and since it’s the right thing to do, you really want a sub-panel in the carport. Also, if you can, make it a 20-amp circuit for the lights, etc. You never know when you want to run a leaf blower or vacuum out your car.

Definitely for an ev run at least 6

The breaker set up is where I landed after further research. I think I'll just run oversized wires once with the right size breaker to an outlet later. I can expand it to a sub panel to manage distribution to additional circuits at the carport. It's all exposed so no need to tear up walls or anything like that. This should give me good flexibility with one wire run. Thanks for the insights

That's going to be most flexible. Run a 100 amp sub panel which should clear all your needs and allow for some extra power should need arise.

Be sure to match wire and connections with correct materials.