Hyundai Smartstream G (1.0–3.5)

Inline · turbocharged · petrol · 2018–present

Also known as: smartstream, g4fp, g4fs, 1.6 t-gdi smartstream, 1.5 t-gdi, g4nn, cvvd, g4kp, g4fm, g4ld, g4kn, g4fl

The Hyundai Motor Group's current petrol family, replacing the Gamma, Nu and Theta across the range — fitted to the Tucson, Sportage, Elantra, i30, Kona and Ceed, in naturally aspirated and turbocharged forms.

Its headline technology is CVVD, continuously variable valve duration — the ability to vary how long a valve stays open independently of when it opens, which no volume manufacturer had put into production before. It lets the engine move between Otto and Atkinson-like behaviour according to load.

That is diagnostically relevant in a specific way: the engine's part-load behaviour and fuel trims will not read like a conventional four, and a driveability complaint interpreted against Gamma or Nu expectations can mislead. Being recent, its long-term failure patterns are not established — which is worth stating plainly rather than assuming the Theta's bearing history transfers, because it is a different design and it does not.

⚑ Smartstream G is Hyundai.s whole current petrol range, not one engine — fourteen models here carry it at 1.0, 1.4, 1.5, 1.6, 2.0, 2.5 and 3.5 litres, from a three-cylinder turbo to a V6. Nothing generalises across it except the naming: a complaint about a Smartstream has to say which.

Cars fitted with this engine

16 generations, across 3 makes. From the authored catalogue — an absent car means the catalogue has not reached it, not that the engine was never fitted.

Genesis

Hyundai

Kia

Information, not instruction

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