Love those old Sveas! The valve in mine finally gave up the ghost and I couldn't get parts; too bad.

My old Svea had a sticker on it detailing the acceptable grades of petrol for Europe (pretty sure it was automotive gasoline) but the North American manual said to use white gas. So it seems like a regulatory thing AFAIK.

The only thing in a Svea that can gum up is the wick, and that is user replaceable. If I were counting on a Svea plus car gas, I'd have extra wicks on hand. I'd put a cover on my pot while cooking too, and be extra careful since IIRC car gas has a lower flashpoint than white gas.