The rule of thumb I saw was that it took more oil/energy to move shipped goods 50miles from the port than it took to get it from China by ship. And that's with time=money; you can cut oil/energy usage by cutting ship speed.

We will still have global trade long after we have no personal car transport.

If I recall correctly, Rubin's point in an article earlier last year, was that oil increases since 2000 had effectively increased transport costs by a margin comparable to a 17% tariff on the goods. And it was the effect of this "tariff" over time that spelled gloom for China and prescribed new trading practices.