Gomez,
Here is your answer. Kubota has come out with a new ZTR mower. Available in 2 sizes. The 18 and 21 hp with deck sizes of 54 and 60. Very nice ZTR for the money. To answer the other question of the G series, they are changing model numbers. Dropping the G1800 1900 and 2000 they came out with a G2160 which is a 21 hp diesel which is less expensive than the 18 and 1900. The unit has power steering like the tg series, hyd deck lift a superb deluxe suspension seat. The new G2460 has a 24 hp gas L/C engine. The last model in its class is the same as the G2160 but with a hyd dump bagger w/rear discharge 48" mower There you go Have a great day.