Road tuning

I am willing to learn EFI tuning but I want to ask if I can start tuning on the road before going deeper and buying a dyno.

Please give more details on the car and what you plan to do with it.

ford focus or a GMC, fuel consumption and power

You can go in the right direction for both but dyno time is needed to really maximize the benefit. This is a very general answer to a very general question.

In terms of fuel economy, you're looking primarily at the air fuel ratio. At cruise and idle the factory ECU will be running in closed loop and targeting 14.7:1 so there is no potential to move this leaner and gain an advantage. Often the fuel consumption advantage comes from the ability to lean out the WOT operation area and this can be done on the road, however you need to be mindful that there is no solid way of knowing what effect your changes are having on torque and power. To get the best results a dyno is going to be essential but you can certainly get started out on the road.

A lot of our members will get their tunes close on the road and then hire a dyno to fine tune the fuel and ignition. This gets you the best results while cutting down on the cost of dyno time.

thank you all.