So I feel extremely dumb asking this and my keywords in Google apparently aren't the right ones either. I have a bottle of fuel system cleaner, Gumout or STP I believe (at work currently so I can't remember). It says it treats up to 21 gallons. So my question is, should I still use the entire bottle, or split it up into two (tank) sessions for best results?

 

I would put my money on doubled exposure time over doubled concentration.

I would also speculate that the "treats up to X gallons" is based on some sort of testing that shows reduced effectiveness beyond that level.

 

go half and half.

 

Nowadays there are so much additives and cleaners in fuel that as long as your using quality brand fuel, the fuel additive is worthless

 

I agree, most fuels available these days have tons of additives already in them. Basically dont buy shitty gas and you should be fine.
Being that you already have the fuel cleaner you may as well use it, personally if you think your injectors or fuel system is really filthy (like you live in a dusty area, etc etc) you may want to just use the entire bottle in one treatment so it works the best it can, if you live in a city area and dont really think its that dirty than spit it in half and only fill up with like 10 gallons each time so its not too dilluted it wont work at all.

 

BG44K

 

+1

 

I'm a big fan of Chevron with TECHRON

 

I always use quality gas, Shell. They had a promotion for this free after rebate with the purchase of some wiper blades. Needless to say I slacked off and didn't send in the rebate.

I just wasn't sure if it was a case where using half would diminish the results or not. I did a split treatment, not that I'm really expecting anything either way.

Thanks guys/gals.