Among the many engines Toyota has built, two stand out. Both of them were conceived in the early 1990s and would go on to power some of the most recognizable Japanese cars ever made. We are talking about the 1JZ and 2JZ engines. Although the technology behind them is now over 30 years old, they are still some of the most popular engines used in builds. But do they differ simply in displacement, or is there more to it? Here’s what you need to know about both these Japanese straight-sixes.