In May 1998, the EN34, HR34, ER34 and BNR34 marked the introduction of 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 reintroduced in updated NEO guise. The R34 GT powered by the RB20DE NEO, coupled with a five-speed gearbox, became the most fuel-efficient straight-six Skyline to date (of any shape). " The 4-speed automatic transmission available on some models in the previous two shapes were discontinued. In its place, Nissan produced a 4-speed Tiptronic transmission for all of the automatic versions (Except the base 2.0L, which has a standard 5-speed gearbox). Only the GT-T coupe variant was sold in New Zealand and Hong Kong from 1997 to 2000 respectively. They were the only two countries besides Japan that sold the R34 GT-T model Skylines new. All Japanese Nissan Prince Store locations that sold the Skyline were renamed Nissan Red Stage.
The C10 series of 1968, which began its development under Prince at the company's Ogikubo R&D centre in the suburbs of Tokyo, was marketed with a Nissan badge. By the time the C10 went on sale, the Prince nameplate had been completely phased out on cars and trucks. The dealer network selling the cars became the Prince channel of Nissan, and the marketing group stayed at the Prince headquarters in Mita instead of moving to Nissan's headquarters in Ginza. The C10 Skyline was launched with Prince's 1.5 L OHC G15 I4 like the S57. A 1.8 L G18 version was also available. A station wagon variant, known previously as the Prince Skyway, was offered with this generation. A hardtop coupé was introduced in October 1970.
The brake- and tail-lights were modified to square units, but now included dual units for both the left and right side of the vehicle. As the Skyline was now a Nissan product, it was repositioned above the Bluebird as a more sport-oriented sedan and coupe, while the Bluebird remained more economical.