The Batmobile was Batman's main mode of transportation. It has been redesigned and rebuilt over the years.
First Batmobile
Batman's Early Batmobile.
Not much is known about Batman's early Batmobile. Due to mechanical trouble, he was forced to abandon it and had a more robust vehicle designed and built by Earl Cooper, an out-of-work automobile designer, with a reputation as a troublemaker in the industry.
Second & Third Batmobile
The Second Batmobile.
Earl Cooper designed a new Batmobile that included such items as a turbine jet, grappling hook, ejection seats, on-board navigation and computer with video uplink, oil spillers and spiked wheels to do damage to an offender's car. Batman had two vehicles with this design. The first with this design was destroyed by the Penguin. After Penguin's defeat, Cooper built a nearly identical vehicle, but with several upgrades. Since there were several episodes following "The Mechanic", it's unlikely that the Batmobile built immediately after would be the "revamp" Batmobile
Interestingly, Bruce saw the exact same design at the Gotham's World's Fair during a date with Andrea Beumont. It's possible that this 'futuristic car' was designed by Cooper as well.
In Bruce's old age, he would ride in a limo very similar in appearance to this Batmobile, suggesting that it was converted.
Also, in The Savage Time, in the alternate timeline, Bruce Wayne, as a resistance leader, also had a very similar attack vehicle in the background.
Fourth Batmobile
The Fourth Batmobile
Batman replaced his car again (presumably also designed by Earl Cooper, but with a different design from the second and third Batmobiles). It served him through his involvement with the Justice League. By the time Terry McGinnis discovered the Batcave, it and the Batwing were still present. This car was also driven by Batgirl at times.
Fifth Batmobile
The Fifth Batmobile
In the mid to late 21st century, Batman replaced the Batmobile with a flying vehicle. This new Batmobile would incorporate a similar or greater range of gadgetry as previous Batmobiles and preclude the need for a Batwing. Bruce said to Terry that the Batmobile could go Mach 3.