Difference in trims
Everything that comes on the hatchback Sport model which is the base model, comes standard on the other models unless specifically upgraded to something better. For full listing of the features and differences between the various trims, see the official Mazda site.
Mazda 3 Sport ($18,175) - 17 inch all season tires are standard, as well as power mirrows, windows and locks. Four speaker audio system with steering wheel controls and auxiliary input are also standard. On the safety side front airbags and anti-lock brakes are standard. Side torso bags are not available, and side head curtain bags are optional.
Mazda 3 Touring ($18,920) - Upgrades safety features to include side torso and head air bags standard, as well as stability control and brake assist. Other luxury features upgraded include a better sound system (six speakers).
Mazda 3 Grand Touring ($20,390) - All the upgrades of the Touring model with more luxury upgrades such as a navigation system, automatic climate control and LED tail lights.
Mazdaspeed3 Sport ($22,240) - The standard safety features of the Touring with upgraded wheels coming in at 18 inches.
Mazdaspeed3 Grand Touring ($23,955) - Adds more luxury features to the sport model with rain-sensing windshield wipers and a navigational system.
Insurance Institute for Highway Safety ratings (IIHS)
Front crash test - Good
Side impact test (no side airbags) - Poor
National Highway Safety Traffic Association (NHTSA)
Front crash driver's side - 4 stars
Front crash passenger's side - 4 stars
Side crash front seat - 3 stars
Side crash rear seat - 3 stars
Rollover rating - 4 stars