Downsizing / Downspeeding Gasoline

A very effective measure to reduce the fuel consumption is to shift the engine operation towards higher loads, i.e. into operating areas of higher efficiency. This can be managed by downsizing of an engine and/or by choosing a longer gear ratio (down-speeding). In combination with turbo-charging such a concept allows to achieve excellent fuel economy together with a very attractive vehicle performance.

AVL Approach

Within the last years AVL has performed a quite significant number of projects on downsized gasoline powertrain, and can offer comprehensive experience for any kind of applications. Especially for the application of highly advanced GDI-tc engines some very specific know how has been elaborated at AVL which is made available for the all development programs of future leading gasoline powertrain.
Methodology and tools applied at AVL for development of GDI and GDI-tc powertrain:
  • Validated simulation for injection process and mixture formation
  • Specific injector test rigs (injector rig, flow bench, pressure chamber, compression simulator) for pre-optimization of components
  • Experience-based development procedures at transparent engines and by use of other optical measurement equipment
  • Validated and series-product proven robustness development process

Customer Benefits

The combination of direct injection and turbo-charging is not only the main reason for the success of the Diesel engine, but also basis for highly efficient fuel economy concepts with the gasoline engine. 
Especially attractive are these GDI-tc engines as flex-fuel concepts, where during operation with E85 (85% Ethanol fuel) efficiency can be improved almost up to 40%.
Additional synergies can be exploited with mild hybridization.


AVL is the pacemaker with GDI technology since more than 20 years. In the last years AVL has developed approximately 100 turbo charged gasoline engines with GDI as well as MPI injection. Besides of high performance applications, a big share of these engines are dedicated to be downsized featuring extreme high fuel efficiency.