Volkswagen TGI (badge, not an engine)

TGI is a badge, not an engine — Volkswagen Group's word for an engine that runs on compressed natural gas, on Volkswagen, SEAT and Škoda.

⚑ Škoda badges the same car G-TEC. An Octavia G-TEC has a TGI engine, and somebody searching one of those terms finds nothing written under the other. They are two words for one car, one on the boot and one on the engine.

⚑ It is bi-fuel, not a gas-only car. A TGI carries a petrol tank as well as the gas cylinders and runs on either — so it has two complete fuel delivery systems, and a fault on one of them leaves a car that still drives. A complaint of poor running that clears when the tank switches is telling you which side to look at, and that symptom does not exist on a petrol car.

The engine underneath is the ordinary one. The 1.0 and 1.5 are EA211, the same family as the TSI sold beside them — the SEAT Ibiza's own list offers a 1.0 TSI and a 1.0 TGI. What differs is the fuel system, not the block, so anything downstream of the gas rail is shared with a car that has no gas rail at all.

Establish the engine code, which is on the engine and in the build sheet, and treat the gas side as its own system.