Optimizing column types for reduced overall database size
In addition to the links a_horse_with_no_name provided on padding a few points here,

This is tremendously wasteful.

latitud double precision DEFAULT 0 NOT NULL,
longitud double precision DEFAULT 0 NOT NULL,
altitud double precision DEFAULT 0 NOT NULL,
velocidad double precision DEFAULT 0 NOT NULL,


You're storing each 0 as a bigint rather than dealing with null which would be (almost) free one bit in the null bitmap.

USE NULL, stop using 0 to represent defaults. Your average row size will drastically shrink.

Also, 

    odometro bigint,


Are you measuring kilometers in micrometers? That's a gigantic number for any odometer representation.