The design changed from modified pickup truck to full SUV

The 4Runner has gotten steadily larger over time

4Runner engines have changed a lot too

As the 4Runner models have grown over the years, the same is true of the engines that power them. At the beginning of the 4Runner's life, all that was available in the United States was a 2.4L 22R I4 engine, but that was quickly replaced by the 22R-E the following year, which introduced electronic fuel injection to the SUV. One year later, a turbocharged version of the engine was made available, and one year after that, Toyota delivered its first V6 option for the 4Runner with a 3.0L 3VZ-E V6.

It wasn't until the third generation in 1996 that Toyota updated the engine options again. The standard issue engine was a 2.7L 3RZ-FE I4 with an option to upgrade to a 3.4L 5VZ-FE V6, which also came standard on some of the more expensive trims. The jump between generations three and four saw the biggest size increase for the 4Runner engines. Not only did the base displacement jump from 2.7L to 4.0L, but the V6 came standard rather than an I4, making a 4.7L V8 the new premium option. Toyota attempted to bring back the 2.7L I4 in 2010, but it lasted just a year.

The forthcoming 2025 4Runner will come standard with a 2.4L turbocharged I4, which has become the primary engine for large Toyota and Lexus models over the last few years.