HHO Generator FAQ: 30 Questions Answered by Experts

Basic Questions

Q1: What is HHO gas? A mixture of hydrogen (H₂) and oxygen (O₂) in 2:1 ratio, produced by electrolyzing water.

Q2: Does HHO violate thermodynamics? No. It improves combustion efficiency of existing fuel — it doesn't create energy from nothing.

Q3: Can a car run 100% on water? No. HHO is a combustion supplement, not a primary fuel replacement.

Q4: How much fuel can I save? Typically 10–25% on gasoline vehicles with proper EFIE tuning; 15–30% on diesel without EFIE.

Installation Questions

Q5: Do I need an EFIE? Yes, on any post-1996 fuel-injected gasoline vehicle. No, on diesel engines and carbureted vehicles.

Q6: What electrolyte should I use? Potassium hydroxide (KOH) is the best choice for automotive HHO applications.

Q7: What water should I use? Only distilled water — tap or filtered water damages plates.

Q8: How often do I add water? Typically every 1–2 weeks depending on cell size and driving frequency.

Performance Questions

Q9: How do I know if my system is working? Monitor LTFT with an OBD-II scanner — it should show −8% to −15% with EFIE properly tuned.

Q10: Why is my MPG not improving? Most common cause: no EFIE installed, or ECU adding fuel back to cancel HHO savings.

Safety Questions

Q11: Is HHO dangerous? With proper installation (check valve, bubbler, fused wiring), HHO presents minimal additional risk.

Q12: Will HHO damage my engine? Properly sized and installed HHO does not damage engines. Excessive amounts without EFIE can cause lean conditions.

Legal Questions

Q13: Is HHO legal? No federal US law prohibits HHO on private vehicles. Emissions testing compliance requires proper EFIE tuning.