I put two things in my fuel.
1. Stabil. I use the dosage for daily use not the dosage for long term storage. The amount is on the back, but, I believe it is 1 ounce for every 5 gallons.
2. I use Lucas fuel additive on every fill up.
I buy it by the gallon - it is very economical if you buy the $30 gallon instead of the one shot bottle in my picture.
My car runs and starts awesome. My CIS system works really well. Better than when I first got the car. I attribute it to the lubrication provided by the Lucas oil and cleaning properties of the Stabil.
Just my opinion and we all know about opinions.
Ray