Difference Between Series 6,7,8 Rx7  

* Series 6 (1992–1995) was exported throughout the world and had the highest sales. In Japan, Mazda sold the RX-7 through its Efini brand as the Efini RX-7. Only the 1993–1995 model years were sold in the U.S. and Canada. Series 6 came with 255 hp (190 kW) and 217ft·lbf.
* Series 7 (1996–1998) included minor changes to the car. Updates included a simplified vacuum routing manifold and a 16-bit ECU allowing for increased boost which netted an extra 10 hp (7 kW). In Japan, the Series 7 RX-7 was marketed under the Mazda brand name. The Series 7 was also sold in Australia, New Zealand and the UK. Series 7 RX-7s were produced only in right-hand-drive configuration.
* Series 8 (January 1999– August 2002) was the final series, and was only available in the Japanese market. More efficient turbochargers were installed, while improved intercooling and radiator cooling was made possible by a revised frontal area. The seats, steering wheel, and front and rear lights were all changed. The rear spoiler was modified and gained adjustability. The top-of-the-line "Type RS" came equipped with a Bilstein suspension and 17" wheels as standard equipment, and reduced weight to 1280 kg (2822 lb). Power was 280 PS (276 hp, 208 kW) (with 330 N·m (243 ft·lbf) of torque) as per the maximum Japanese limit. The Type RZ version included all the features of the Type RS, but at a lighter weight (at 1270 kg). It also featured custom gun-metal colored BBS wheels and a custom red racing themed interior. Further upgrades included a new 16-bit ECU and ABS system upgrades. The improved ABS system worked by braking differently on each wheel, allowing the car better turning during braking. The effective result made for safer driving for the average buyer. Easily the most collectible of all the RX-7s was the last 1,500 run-out specials. Dubbed the "Spirit R", they combined all the "extra" features Mazda had used on previous limited-run specials and all sold within days of being announced. They still command amazing prices on the Japanese used car scene years later.