Is a diesel tuner right for you?

The sentiment of a famous country song says it all, “…. there can’t be a girl too pretty or a car too fast” —– or in our case a diesel engine that is too powerful! The promise of added performance with a diesel tuner is a siren’s song that is easy to fall prey to. Before you invest in one you need to understand how a tuner works and its possible ramifications.

The electronic diesel

The modern engine replaced the pump-line-nozzle system with common-rail electronic injectors. Also integrated is usually turbocharger boost control. Thus, the amount of fuel, the timing of the injection pulse and the boost pressure can all be manipulated electronically. In the parlance of engineering the software in the electronic control unit (ECU) is identified as the calibration.

The ECU is able to be recalibrated (reflashed) to alter the timing and length of the injection pulse along with the boost pressure. This is the source of the power gain. The calibration a diesel tuner employs is more aggressive than that fitted by the engine manufacturer.

This now begs the question: Why can’t the factory do it? They could but they choose not to. Not because they want to gyp you out of power but their concern is reliability of the engine and drive train along with emissions output.

With any engine power is produced by cylinder pressure from the expansion of the ignited fuel burning across the bore. The higher the power the more heat generated and the greater the cylinder pressure. Heat and pressure when excessive will end up hurting the engine. The logic of all engine manufacturers is to build an engine/transmission that can take more power than the calibration produces. It is like building a truck that can carry more weight than it is rated for — it is the buffer for when it is overloaded.

An aggressive calibration either diminishes or removes the safety buffer. OE manufacturers are usually able to tell if an aftermarket tune was installed. Some tuners leave a finger print in the ECU and in most cases will void the warranty on the engine/driveline. The Diablo Sport InTune says it does not. The InTune SF tested is easy to use, is well supported and is designed and made in America.

Choose wisely

A calibration that is identified for towing offers the best of both worlds in a truck that is not continually taxed.

A towing calibration will provide better throttle response, increased power and fuel economy. It shrinks the safety zone but does not eliminate it. If the engine is really worked hard then I suggest keeping the stock calibration and just go a little slower up the hills. Why risk an expensive repair.