what is considered to be the normal range for LT and ST fuel trims?
Is it dependent on other things like injector size and such?

I have the obd 2 datalogger and there are 2 sets of ST/LT trims. which ones should i be looking at?

thanks
tim

You should always try to get your STFT and LTFT as close to ZERO as possible, so the car's ECU can make adjustments within it's range.

^^ true, but it's pretty hard to get your ltft to stay around 0. stft should definitely stay within +-5% for the most part. concentrate on your stft, it's more important. my ltft seems to be always changing drastically, for the most part try to get it to stay within -15%, it's better fot it to be in the negatives than the positives.