The majority of diesel emissions are unspent fuel and, with HHO injection, more of the fuel is combusted. That’s why HYDRO-MAXX provides more power with less emissions.

The studies below are from three different types of field applications were conducted using the Hydro-Maxx Onboard Hydrogen/Oxygen Generator System on various applications.

Case Study - Over the Road

otr_1The test vehicle was a 2007 Volvo with a 468hp Volvo Turbo-Diesel engine, one of about twenty trucks in the fleet. The vehicle showed 12 EGR errors codes on the ECU prior to the installation of the Hydro-Maxx system. Codes were reset, and after 4 hours of clean out time the EGR NEVER failed again. If the Hydro-Maxx system was turned off, the EGR error would occur within a day. In nine months and over 187,000 miles of driving this truck was the only one in the fleet that did not need an EGR replacement. All the other trucks in the fleet required 2-3 changes a year at a cost of $1,700 per EGR plus 8 hours of labor. Additionally, the oil change interval for the test vehicle was increased from 15,000 to 25,000 miles due to the oil cleanness, equating to 5 fewer oil changes per year.

Operator Testimonial: “I love this truck with HHO on, hate it when its not. I used to take the hill coming out of Cincinnati into Kentucky in 6th gear. Now I do it in 8th gear” -Bill B.

Truck: 2007 Tier 2 Volvo over the road 18 wheeler
Baseline mpg:  5.5
Field Test:  187,000 miles over 9 months
System Cost:  $15,350
Payback:  9.6 months




HHO on


9 Month Savings*


5.5 mpg




EGR changes





Oil changes

15,000 miles

25,000 miles

$180 per oil change


Total savings





*Based on 7% improvement in fuel economy.


Case Study - Chiller/Heater

reefer_1The unit was a 1999 Carrier with a Mercedes 34 hp engine. This contractor carried critical freight for Federal Express all over the country on a moment’s notice. With a 54% Opacity emission, he could longer enter the state of California due to the CARB regulations. After 1 hour of turning on the Hydro-Maxx system the Opacity emissions were reduced to 1.117%-- a 98.8% reduction! The owner reported that fuel consumption was reduced from 1.5 gal/hour to 1 gal/hour.


reefer_2 reefer_fuel reefer_opacity


Case Study - Stop and Go

An urban county government municipal solid waste fleet needed a way to reduce emissions as they were dangerously close to exceeding EPA air quality standards. After installing the Hydro-Maxx system, baseline emissions were reduced 48.4% after the first hour of operation. The operator also reported more power and speed from the truck -- finishing the route 2 hours early for the first time ever!


s&g2 s&g_opacity s&g1

What Can You Expect?

HYDRO-MAXX will increase fuel economy in most diesel engines. You can expect up to a 35% increase in
fuel economy depending on the make and model year of your engine.

Average results obtained by installing a HYDRO-MAXX System will vary depending on engine model, year, and service history. The following table lists the expected range of improvement based on our extensive on-road testing.

Emissions Reduction
Nitro Oxides (NOx) Reduction Up to 60%
Carbon Monoxide (CO) Reduction Up to 100%
Hydrocarbons (HC) Reduction Up to 100%
Particulate Matter (PM) Reduction Up to 95%
Opacity (Smoke) Reduction Up to 98%

Operating Results
Increase in Torque/Power 8 to 10%
Fuel Savings Up to 35%
EGR Replacements 0
Fewer Oil Changes 40%

Typical oil change frequency with and without HHO
Milage Interval (x 1000) 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75
Without HHO     X     X     X     X     X
With HHO         X         X         X