Difference in Mazda 3 and Mazda 3i?

The Mazda3 is offered in two versions- 'i' and 's'. The 'i' is offered in Sport, Touring and Grand Touring trim levels. The 's' is only available in the top-level Grand Touring trim level as of the 2013 model year. The 'i' Sport is only available as a 4-door sedan, all other trim levels are available as a 4-door sedan or 5-door hatchback.

The 'i' models feature Mazda's highly-efficient 2.0L 155hp "SkyActiv" 4-cylinder engine paired with either a 6-speed manual or 6-speed automatic transmission. The 'i' has a 40mpg Highway fuel economy rating.

The 's' has a slightly more powerful 167hp 2.5L 4-cylinder with a 6-speed manual or 5-speed automatic transmission. This engine is much less efficient, rated at only 29mpg Highway. This engine is an older design and does not feature Mazda's new "SkyActiv" technology. Despite the slight increase in power, the difference is negligible under normal driving conditions.

A redesigned 2014 Mazda3 is expected to be released before the end of 2013. All models will feature the latest fuel-economy technology.