How to best use instrumentation...?
 

I have a Bluetooth OBD2 reader which I am using with my HTC desire and the Torque app.

I have also just ordered an Ultraguage EM - which I'm hoping will work with my VW Golf, if not I'll use with my Daihatsu Cuore (which is actually a Perodua Kelisa!)

Use of the instantaneous MPG readout is an obvious one- but there is also a lot of stuff available like fuel trim, timing advance, Lambda voltages etc.

I'm wondering if there is an easy guide somewhere to what one should be monitoring to ensure the engine is running well. ie: What should I be looking for when looking at fuel trims and Lambda switching?

How can I tell if the ECU is in open or closed loop??

TIA

I have an Ultra Gauge (not em) and I display instant mpg, % load, trip mpg, average mpg (tank average), coolant temp, and voltage.

Kirk

I got my first scanner, an Ultra-gauge, a couple of weeks ago. I'm not really sure the best way to use it yet. But what I do is show the instant MPG, trip MPG (I reset it every time I get gas), and short trip MPG (resets automatically every time you start the car).

Basically what I try and do is keep the instant MPG higher than the short trip MPG, and try and keep the short trip MPG higher than the trip MPG.

I also have it display miles to empty, water temp, and battery voltage. None of those help you drive more efficiently, I just like to have them for information purposes.

Don't worry too much about all the technical info that is available. This information was meant to help troubleshoot problems and do tests. The only numbers you need are the current MPG, trip MPG, and maybe % load. Monitoring these numbers will help you improve your driving. Things like coolant temp, air intake temp, etc. are useful in fine tuning your techniques.

You should assume that your engine is running well if you don't notice anything unusual or have any check engine lights. Just because you now have the info doesn't mean you need to monitor it to look for potential problems. Your ECU already does that for you and will let you know about it.

I'd strongly recommend against chasing a good instant, every drop of fuel you burn is an investment, and you reap the rewards down the road.

I never really mind burning more fuel to get accelerated or up a hill, as I know it will be converted into distance traveled as I decelerate or descend. (so long as I do not have to use the brakes)

I focus on avg mpg and water temp (mainly on hot days)