Whats the difference between two cars of the same model, from different years?

The best of the bunch by far is the 2012 Mazda 3 Skyactiv (SA). Skyactiv for Mazda is a clean sheet approach to re-engineering the car piece by piece bit by bit. Borrowed from the brands gram strategy to build one of the finest two seaters the world has ever seen, Skyactiv is a the new suite of engine's, transmissions both manual and automatic, chassis and not to leave out the iLoop referring to an ultra capacitor that can fully charge in one minute due to letting off of the gas/braking which triggers either distribution of re-generated electricity for use inside the car's cabin allowing any extra energy to be channeled to the car's battery. The Skyactiv engine is a high compression power house. Don't let 155hp fool you. Running the air conditioner, playing the stereo, interior lights and so forth saps horsepower (5hp) to keeping the electronics operative while driving. Due to the iLoop the car's battery, alternator and engine are freed up due to regenerative braking, when Mazda states 155 hp you get it where you need it most, everyday all day, through the wheels. Working in tandem with the Sky activ engine is the sky activ transmission which is the best of a double clutch system, continuous variable transmission and single clutch transmission. Mazda has a torque converter that locks in below 5 miles an hour. The driver feels a linear power surge that matches the revs to the propulsion of the vehicle, thus it doesn't scream going no where fast, then downshifts as if taking on a headwind when their is no such thing on a given day. As a result, the 3 drives big. The chassis is reinforced in the A and B pillar and re-engineered to absorb a head on collision throughout the car's body instead of the front crumple zone only. When you put it all together it is a finely crafted machine that Mazda has every right to be proud of, and the owner has the excitement of many wonders. I wonder how they did that? I wonder if it will always be a driver's car? I wonder why Mazda doesn't tell its story? The net result of a 14.5 gallon tank is 29 mpg city a combined average of 33 mpg a highway figure at 40 mpg. When you do the math the most miles the car can travel on a tank of gas is 546 miles before fill up. Mixed driving is going to put the driver at 450-470 miles before fill up. When driven between -80 mph plus the car's gas mileage has been known to drop a paltry 26 mpg. The previous models share the Mazda's venerable MZR engine architecture and transmissions. With the larger engine one can expect greater trips to the the gas station, a peppier ride and a car that is capable of 10 years 200 plus thousand miles. Best

Well the 2004-2009 Mazda 3 were exactly the same apart from very minor changes to tail lights and interior features/colors offered through the years. In 2010, the Mazda 3 was completely redesigned with a new body, suspension, engine, and interior. The 2012-2013 model is the same as the 2010. except that for 2012 they introduced a new engine option, the Skyactiv engine. And for 2012-13, they started offering gloss black painted front grills, while the 2010-2011 model has flat-black front grills. The gloss black in the 2012+ model makes it look like a more expensive car.