[Gregski]

Long Term Fuel Trims and Short Term Fuel Trims, yeah we all heard the terms or the four letter acronyms LTFTs and STFTs, but what are they really?

A long time ago a teacher I had would tell us to substitute a word for a term we did not know instead of defining it for us, and it worked, so let's try this, any time you see the word Trims substitute it with the word "Changes"

So Long Term Fuel Trims become Long Term Fuel Changes and Short Term Fuel Trims become Short Term Fuel Changes

You could also use the word Adjustments or modifications, or what ever you come up with that works for you.

Now some may find the following analogy or example silly, but I think it works as we all can relate to it, plus everyone enjoys a good short story.

So it's the first day of Winter and you have to get dressed for school. So you put on the usual a T shirt and some jeans (socks, shoes and underwear is assumed) so in other words your VE outfit your Volumetric Efficiency or standard outfit.

On Monday you step outside and start walking to school, soon you find it's colder than you expected but you press on.

Tuesday same thing you throw on a different T shirt but still just a T shirt and a pair of jeans and you head out, freezing your butt off all the way there.

On Wednesday you step outside in your T shirt and a pair of jeans and you say screw this I am making an adjustment and you grab a jacket and put it on and zip it up to the top (there you just made a Long Term Fuel Trim) from here on out you will bring a jacket until the weather will get too hot again. You walk to school wearing that jacket but once you get to class you are sweating, you think nothing of it.

Thursday you head outside in a T shirt, jeans, and jacket of course, but half way there you think I'm getting hot, I should unzip my jacket (A Short Term Fuel Trim change) you get to school and you are no longer sweaty like the day before, you think I think I got this

Friday morning you put on your T shirt, jeans, and a jacket but you don't zip it up today, nope the Short Term Fuel Trim has now become part of the Long Term Fuel Trim baseline if you will

now if you start walking to school and it gets too cold, starts raining or snowing, by all means you have the freedom to zip up your jacket again, making yet another Short Term Fuel Trim adjustment/change