At Tyres.co.uk, tyre choices for Nissan Sunny include Michelin Energy Saver+ and Goodyear EfficientGrip Performance, both in the size 185/60 R14 82H specifically for the 1988-1990 Sunny 1.8 GTi 16V models. Other generations and trims of Nissan Sunny have various different factory fitments, so please check the requirements of your registration, placard, and handbook before purchasing.
The Nissan Sunny manufacturer tyre-information placard is located on the driver's side B-pillar, which is visible when the door is open. It indicates the approved tyre sizes and their corresponding pressures. However, do check the tyre sidewall as well as the handbook because Nissan Sunny wheel specifications change with the generation and trim.
Nissan Sunny two wheel drive versions do not need all four replaced: replace tyres as an axle pair and fit any new pair to the rear axle as per UK tyre safety guidance. The exception is the Nissan Sunny 1.6 4WD. It must have four tyres that are identical in size, make, construction and tread design, so all four tyres may need replacement.