Ecotuning: lowering fuel consumption
The real story!
Many people claim that after modifying the ECU their car is using less fuel than before the tuning. As a matter of fact they are getting fooled because they see every day an increase in mileage in the dashboard which is not correct any more. The mileage calculation has altered by the modification of the maps changed by the tuner. The only way, other than ecotuning, to experience an improvement in fuel efficiency after performance tuning is to adjust your driving style in a way to use the extra power and torque to stay in lower revs comfortably for the engine and shift faster. For everything other than that…
More power = more fuel
Of course, a large increase of injected micrograms of fuel won’t make an engine run more fuel efficiently. Power has to come from something. I know many customers want maximum power and maximum mileage unfortunately that is not possible. However it is possible to make most turbocharged diesel engine run more fuel efficient but in most cases the engine won’t gain much torque with the most efficient calibration.
The most often used approach to reduce fuel consumption is by reducing the rpm the driver is making or which he needs to make to cover a certain distance. The possibilities to lower the amount of rpm the driver is making depends not only on the type of engine but also the size of the vehicle it is used in. This approach for a small engine in a small vehicle is totally different then the same engine in a bigger vehicle.
The easiest way to make a diesel engine run more efficient is by altering the start of injection and raising smoke limitations. The downside is that this will increase the amount of pollution like NOx and particles.
Lean burn mixture
A more complicated way to make the engine run more efficiently is by changing the air fuel mixture by changing the turbo, lambda and common rail maps. This can only be developed on dynamometer which is specially equipped with a system to make measurements of the fuel consumption while driving. After testing for a few months we gathered the information to make an engine run more fuel efficiently with more or less the same emissions and without harming the engine.