Does anyone use any type of fuel additive when they fill up every 3000 miles? I used to use one in my older explorer just so that there wouldnt be any water buildup or wear on the injectors. My 06 civic runs on 87 octane which isnt the cleanest fuel, do you think it is necessary to use an additive that increase fuel quality? I'm sure it could run on a high octane but that's too expensive nowadays. Any suggestions? maybe this isnt necessary at all.

 

If your manual does not specify to run a higher grade (octane) fuel, then it is just a waste of money. Higher octane fuel is only for higher compression and forced induction motors to prevent detonation.