Shares of Toyota Motor (TM -1.65%) rallied 11.8% this week, according to data from S&P Global Market Intelligence.

Toyota didn't have any major company-specific news this week, as it doesn't report Q2 earnings until Aug. 7. However, there was big news on the trade front, with the Trump administration and Japan inking a trade deal that would put milder-than-expected tariffs on Japanese imports, including Toyota cars.

Will recent tariffs actually give Toyota a leg up on U.S. automakers?

On Tuesday, the Trump administration struck a trade deal with Japan, which would lower the threatened "Liberation Day" tariff rate from 24% to 15%. While that might not seem like that much of a decrease, cars are high-ticket items, so the new tariff duties could make thousands of dollars' difference to the end price consumers may have to pay.

Even though it appears Toyota cars made abroad will face tariffs going forward, the stock went up anyway. Not only that, but U.S. carmakers complained to the administration that the lower rates now put them at a disadvantage. This is because even American automakers import some of their steel and aluminum, which will now be tariffed at 50%, while other components, even for U.S.-manufactured cars, are imported from overseas, and will also be tariffed.

And while part of the Japan deal involves removing restrictions on U.S. exports to Japan, U.S. automakers don't appear to believe the deal will result in any new market share gains there.

Image source: Getty Images.

Will U.S. automakers benefit from the trade negotiations?

Toyota is the second-largest carmaker in the world, both in terms of global and U.S. market share, so the all-important final tariff figure could have significant consequences for U.S. auto markets.

There are a lot of moving parts with regard to tariffs, however, as Toyota makes cars all over the world, with inputs and other sub-components also coming from various places. To further grasp the total consequences of the deal, investors in either Toyota stock or the "Big Three" U.S. carmakers should keep their ears out for more clarity when Toyota reports earnings in August.