You will probably remember playing with the hosepipe in the garden: Squashing the pipe flat causes the water to fan out at high pressure. Toyota’s new VVT-i D motor uses the same idea to atomise and distribute fuel around each cylinder. Avantages: Increased fuel spray atomisation for more uniform combustion Compression ratio is increased to 11.0 (compared to 9.8 for the VVT-i engine) Petrol no longer sticks to the injection port during cold fuel injection, which results in less hydrocarbons, meaning a cleaner and more efficient engine. The VVT-i D4 engine is 8% more efficient than Toyota’s award-winning, and very economical VVT-i engine. ut most importantly, D4 makes a difference you can really see and feel!