XC90 is supposed to be about 300 g/km and 22mpg,
so it would need to travel about 500 miles.
Maybe slightly overstated.

Are you sure you're not confusing CO2 with CO?  CO2 is an unavoidable
product of burning fuel, and a car engine will produce lots of it.  CO,
on the other hand, is a product of burning fuel inefficiently, and is
much more harmful (often lethal in confined spaces) but should be almost
entirely eliminated by the catalytic converter.

Don't fret over CO2 emissions.  Yep, you're contributing to the
greenhouse effect, but by a trivial amount when compared with other
sources.  If I were you, I'd be more worried about the potentially
lethal dihydrogen monoxide that your car is emitting.

500 grammes a mile, sounds about right.

The carbon and hydrogen in the fuel end up as carbon dioxide (four times the
mass of the carbon, roughly)  and water vapour (eight times the mass of the
hydrogen.)

So if you use fifty litres of fuel, which is somewhere in the vicinity of fifty
kilogrammes, you can anticipate about 250 kilos of CO2 and a similar mass of
water vapour.

Of course, if you do the same thing with a steam train you produce twice this,
all else being equal, a horse is probably ten times, a human being walking the
trip probably manages to produce more like 25 tonnes of CO2 and a lot of other
waste products.