How do turbo cars give better fuel economy?

Fuel savings with turbos come two fold –

Firstly a 1.6 litre turbo engine is physically smaller and lighter than a similarly powered 3.0 litre non turbo (naturally aspirated engine). This means fuel savings from weight and due to smaller and less internal engine components, causing less drag as they move around together.

For the second benefit, it is important to understand how an engine and turbo works. Your engine in simple terms, be it diesel or petrol, is an oil burner. It burns fuel to make power to turn the wheels. Despite uncountable technological breakthroughs, this is still a very inefficient way of producing engery. The energy extracted from your fuel breaks down to this – Approximately 35% to power (useful work), 35% wasted through the exhaust, 30% wasted as heat which gets transferred through the coolant and oil. Diesel power efficiency is slightly higher, hence why diesels can get better fuel economy.  

Turbos are powered by the normally wasted energy that flows out of the exhaust pipe. A turbo is essentially two fans joined by a common shaft. One fan lies in the exhaust stream, the other in the intake. The flowing exhaust spins the fan (called the turbine), which powers the corresponding fan in the intake (the compressor). This creates boost pressure, allowing more air to be forced into the engine. In basic terms if you run 14psi of boost into a 1.6 litre engine, it can now flow as much air, and with the correct fueling, produce as much power as a 3.2 litre non turbo engine, but with less weight and better efficiency as discussed earlier. Turbo fuel saving efficiencies can be in the range of 8-10%, but be warned, put the foot down and these little engines will show you just how much power they have, and that they can burn just as much fuel as the big boys when at full throttle.

We are well trained and have plenty of experience with turbo systems at Steve Sorensen Mechanical. We can take care of any Browns Plains turbo problems, including –

Standard waste gate turbo

Waste gate solenoid problems

Variable geometry turbo

Boost leak finding

Misfires under boost

Diesel turbo systems

Turbo replacement

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