The HR/ER/BNR34 was released in May 1998, and was made with the shortcomings of the R33 upgrade fresh in their memory. The R34 now featured more emphasis on sportiness, and featured the more fuel-efficient and environmentally-friendly RB25DET NEO engine. The RB20E engine was discontinued in the R34 base model (GT), and the RB20DE, after last being used in the R32 Skyline, was given the once over, to produce much better fuel economy.

The RB20DE NEO proved to be more than just hype, as the R34 GT would turn out to be the most fuel efficient inline-6 skyline ever made. The 5-speed automatic transmission was discontinued. Instead, Nissan produced a new 4-speed electronic transmission.

Nissan returned the Skyline to its sporty roots and the public responded. The R34 easily surpassed the R33 in popularity and was quickly embraced by the tuning community. Tuned R34's have become a fairly common sight driving in the street and the sedan version is a popular alternative to Toyota's 1JZ engined sedans, the MarkII/Chaser/Cresta/Verossa. The popularity of the sedan version was further boosted with the campaign of a R34 in the D1 Grand Prix by Blitz and driven by Drifting celebrity, Nomura Ken (Founder/Owner of Uras).

http://en.wikipedia.org/wiki/Nissan_Skyline#R34

Models:

-GT - 2.0 L RB20DE NEO I6, 155 ps (114 kW)

-25 GT, GT-X, GT-V - 2.5 L RB25DE NEO I6, 200 ps (147 kW)

-GT-FOUR - 2.5 L RB25DE NEO I6, 200 ps (147 kW) AWD

--GT-T - 2.5 L RB25DET NEO turbo I6, 280 hp (206 kW, 343 N m)