I've gone through some techron and now have been trying some redline fuel system cleaner. I put a little bit of the redline in every other fill up. Paid $10 for it and ya I can tell a little difference the first little while but it hasn't cured my bad idle that seems to be cleared with each little fix but then returns to 500 rpm after a little time. Bad grounds and electrical connections have been the main problems or actually the vacuum leaks. I've had plugged up fuel filters and change them about once a year. So putting fuel cleaner through is just a little lady luck in my opinion. But its kind of like having that royal match bet out there. Sometimes it can help but most of the time its a waste of money.