Standard ABS for all models and an available 6-speed automatic transmission are key 2005 changes for the Mazda 6. Four-door sedan, wagon, and hatchback body styles are offered in base, Sport, and Grand Touring equipment levels. The "i" designation denotes a 160-hp 4-cyl engine and is limited to sedans and hatchbacks. Uplevel "s" versions use a 220-hp V6 and come in all three body types. Both engines come with a 5-speed manual transmission. The i models are available with a 4-speed automatic. For '05, s versions exchange an available 5-speed automatic for a 6-speed, making this one of the few cars in its price range to offer that feature. Both automatics have a manual shift gate. Standard on all Mazda 6s are antilock 4-wheel disc brakes; the ABS feature had been optional on base-level versions. Traction control is also standard on all models for '05; it had been optional on i versions. Base; sedan has 16-inch wheels, all others have 17s. Front torso side airbags and head-protecting curtain side airbags for both seating rows are optional on the base i sedan and standard on other 6s. All models have a tilt/telescope steering wheel and split folding rear seatbacks. Leather upholstery and heated front seats are standard on Grand Touring models, optional on Sports. A sunroof is standard on Grand Touring versions, optional on other 6s.