Increasing Gas Mileage with Water

Best Stainless Steel Grade for Hydrogen Electrolysis Electrodes

Hydrogen electrolysis electrodes must resist corrosion while conducting electricity efficiently. Common choices are 304L and 316L stainless steels, with some considering titanium for its corrosion resistance. The goal is to maximize hydrogen output and electrode life. Below we compare these materials in terms of corrosion resistance, conductivity, and longevity:

A typical dry-cell HHO electrolyzer uses stacked stainless steel plates as electrodes (example from a DIY project). Such cells often employ 304 or 316L stainless steel due to their good corrosion resistance and reasonable cost. Neutral plates and insulated spacers are used to increase gas output while preventing short-circuits.

• 316L Stainless Steel: This molybdenum-alloyed stainless steel offers superior resistance to pitting and chloride-induced corrosion than 304-grade. In practice, 316L is highly durable in the alkaline electrolytes (KOH, NaOH) used for HHO generators – far less prone to rust or pitting over time. It “resists electrolysis-induced oxidation” effectively in mild alkaline conditions. Because 316L can tolerate harsher conditions, it tends to last longer when electrolytes become contaminated or if any salt enters the system. Its electrical conductivity is similar to 304 (both are relatively low compared to metals like copper), but this is usually mitigated by using thin plates and large surface areas. The trade-off is cost: 316L plates are a bit more expensive. Nonetheless, many experts and users favor 316L for critical electrolyzer applications, since even if it does corrode, it will do so more slowly than 304 (for example, in one forum an engineer noted that even 316 will eventually deteriorate in chloride-containing water, just not as fast as 304). Overall, 316L is often recommended as the best compromise for efficiency and durability in HHO electrolyzers.

• 304L Stainless Steel: Grade 304L is the workhorse stainless steel and is widely used in DIY electrolyzers because it’s affordable and readily available. It has slightly less resistance to pitting and corrosion than 316L, but in the context of a hydrogen cell using pure or alkaline water (no chlorides), 304L holds up very well. In fact, many HHO generator designs use 304L plates and report satisfactory longevity. A recent study on HHO generators noted that 304L is cheaper and still provides sufficient corrosion resistance in alkaline electrolytes, making it a popular choice for most consumers who may not notice the performance difference vs 316L. Unless the cell environment is extremely harsh (strong acids or chloride contamination), 304L can serve nearly as long as 316L. It does corrode slightly faster – users often observe a light brown discoloration or rust in the water over time as iron leaches out, especially at the anode. For example, one builder mentioned that even with 316, the water eventually turned brown from iron oxide, illustrating that any stainless steel will slowly corrode during electrolysis. The key advantages of 304L are its low cost and wide availability in mesh or plate form. For many applications, 304L offers a good balance of efficiency and durability, as long as the electrolyte is kept free of chlorides and the system is maintained (periodic cleaning or flushing can greatly extend electrode life). In short, 304L is a cost-effective choice that sacrifices a bit of longevity in exchange for savings – a valid trade-off for many hydrogen booster projects.

• Titanium: Titanium electrodes are extremely corrosion-resistant – far more than any stainless steel. Titanium will not rust or pit even in seawater or highly oxidative environments, which makes it attractive for long-term durability. However, pure titanium suffers from a phenomenon called passivation: it quickly forms a thin oxide layer on its surface, which, while protective, is not very conductive. This means an uncoated titanium electrode can exhibit higher resistance and lower electrolysis efficiency (higher overpotential) compared to a bare stainless steel electrode. In fact, an experiment comparing stainless vs. titanium electrodes in an HHO dry-cell found that 316L stainless steel yielded better gas production performance than pure titanium electrodes. The likely reason is that the titanium’s oxide film reduced the effective current going through the water. To use titanium effectively, industry often coats it with a catalyst (for example, platinum or mixed metal oxides like ruthenium/iridium oxide) – this creates an inert, conductive surface on the titanium substrate. Platinum-coated titanium anodes are considered a gold standard for water electrolysis because they combine titanium’s corrosion immunity with platinum’s excellent catalytic conductivity. The downside, of course, is cost: titanium (and especially noble metal coatings) are much more expensive than stainless steel. Titanium is also lower in density and about as conductive as stainless in bulk, so it’s lightweight and strong – useful in design, but the surface behavior is the main issue. In summary, titanium offers maximum durability but requires special treatment to achieve maximum efficiency. It could be chosen for a cell where electrode replacement is extremely difficult or for very long-term systems. For most HHO boosters, though, the modest gain in longevity (and freedom from rust particles) may not justify the much higher expense and potential need for catalytic coatings.

Note: Regardless of stainless grade, all steel electrodes will gradually introduce some iron into the electrolyte over long use, especially on the oxygen-generating anode side (which can lead to orange-brown “rust” in the water). Using distilled water with a proper electrolyte (KOH or NaOH) helps minimize impurities that accelerate corrosion. Many experts suggest that if budget allows, 316L is preferable because it better withstands any aggressive conditions. For ultimate durability (at a high cost), platinum-coated titanium electrodes can be used – a professional solution where electrodes essentially do not wear out. In practice, most users find 304L or 316L stainless steel electrodes strike the right balance between efficiency, durability, and cost for hydrogen production.

Best ECU and Tuning Setup for a Hydrogen Booster (2017 Chevy Colorado)

When adding a hydrogen (HHO) booster to a 2017 Chevy Colorado, tuning the engine’s electronic control unit (ECU) is critical to achieve fuel efficiency gains and maintain engine safety. The extra hydrogen gas acts as a combustion enhancer, but the stock ECU is programmed for gasoline and may not automatically accommodate the change. Here we identify the best ECU solution (brand/model) and the tuning parameters needed to optimize performance:

ECU Choice and Setup

For a modern vehicle like the 2017 Colorado, you have two main paths: reprogram the stock ECU with specialized software, or use an aftermarket/piggyback ECU controller. Each has its merits:

• Reflashing the Stock ECU: The factory ECU in the 2017 Colorado is a sophisticated unit that can be re-tuned. One of the most popular tools is HP Tuners VCM Suite (with an MPVI2 interface), which allows direct modification of the Colorado’s ECU maps. This approach keeps all OEM safety features (knock control, engine diagnostics, etc.) intact. Using HP Tuners or similar, a skilled tuner can adjust fuel delivery, ignition timing, and sensor calibrations to account for hydrogen. Many community experts lean toward this option because it leverages the robust stock ECU. It’s essentially free in terms of hardware changes – just a software update – and the Colorado’s ECU is fully capable of running slightly leaner mixtures and retarded timing when properly tuned. If you go this route, it’s advisable to work with a tuner who has experience with HHO or lean-burn tuning, as the strategy is a bit different from a standard performance tune.

• Standalone Performance ECU: If an extreme level of control is desired, one could install a standalone ECU from top-tier brands like MoTeC or Haltech. These aftermarket ECUs replace the factory computer and can be programmed to very specific requirements (for example, running on alternative fuels or dual-fuel scenarios). MoTeC is widely regarded as a high-end choice – “MOTEC is probably one of the best ECU companies on the planet” according to one fuel-economy project testimonial​

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  . A MoTeC M1 series or Haltech Elite ECU would allow complete customization: you could map separate fuel tables for when the HHO is on, control a hydrogen injector or PWM if one is used, and finely tune ignition. However, installing a standalone in a 2017 truck is a significant endeavor: it’s expensive and requires retuning every aspect of the engine (idle, cold start, etc.), essentially starting from scratch. For a hydrogen booster that only supplements the stock fueling, a full standalone is usually overkill. That said, some tuners have had success with mid-range piggyback ECUs (like an AEM Fuel/Ignition Controller or similar) to gain a bit more control without replacing the whole ECU. Those allow timing retard and fueling tweaks while the stock ECU still runs the show in the background.

A specialized “hydrogen fuel tuner” controller (right) can intercept or adjust sensor signals for an HHO system. These piggyback devices, like EFIE (Electronic Fuel Injection Enhancer) chips, connect to the vehicle’s sensors or OBD-II port to trick the ECU into leaning out the mixture and/or adjusting timing when hydrogen is being used.

• Piggyback Hydrogen Controllers: There are also purpose-built controllers for HHO systems that work alongside the stock ECU. One example is an EFIE (Electronic Fuel Injection Enhancer) device, often marketed as an HHO chip or hydrogen controller. These units do not replace the ECU; instead, they modify the sensor inputs (such as the oxygen sensor, MAP sensor, or IAT sensor readings) to influence the stock ECU’s behavior. For instance, an EFIE will add a small offset to the O₂ sensor signal, making the ECU “see” a richer mixture than actual – as a result, the ECU leans out the fuel delivery thinking it needs to correct a rich condition​
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  . Similarly, HHO controllers might alter the manifold pressure reading to make the ECU think the engine is under lighter load (so it delivers less fuel)​

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  . Products like the Volo FS2 HHO Edition or the Better Fuel ProTuner fall in this category. They are essentially plug-and-play chips that interface with the OBD-II port or sensor harness and implement a pre-programmed tweak for HHO. The advantage here is simplicity – no extensive tuning knowledge is required from the user, as the device comes preconfigured for leaning out the AFR when hydrogen is on. The ProTuner, for example, combines an EFIE, a MAP/IAT modifier, and a PWM output for the HHO generator in one unit​

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  . These have been reported to yield substantial fuel economy improvements (on the order of 15-50% depending on gas or diesel) by maintaining an optimal lean burn with hydrogen assistance​

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  . If one is looking for a ready-made solution, an EFIE/MAF controller from an HHO kit supplier is a viable choice. Just ensure it’s compatible with a 2017 OBD-II system and that you can revert to stock easily if needed.

Recommendation: For a 2017 Chevy Colorado, using the stock ECU with custom tuning is generally the best approach to balance reliability and performance. The factory ECU is sophisticated and already calibrated for the engine; by flashing in some targeted adjustments (or using a piggyback to nudge those adjustments), you retain all the engine protections. A specific ECU model recommendation in this context would be the HP Tuners MPVI2 tuning interface (which works with the Colorado’s stock ECU) or a dedicated HHO controller like the EFIE/MAF Advanced HHO tuner. The MPVI2 isn’t an ECU itself, but rather the tool that unlocks the full potential of the stock ECU. If one insists on a standalone ECU, a MoTeC M130 or Haltech Elite 1500 could certainly do the job – they are proven in controlling alternative-fueled engines – but the cost and complexity are high. Most users report success with simply tweaking the stock programming or adding an EFIE. In short, retain the OEM ECU and either remap it or use a quality HHO-specific piggyback. This gives a good balance: you leverage GM’s engine management (preventing errors and catastrophic leanness) while nudging it toward better efficiency with hydrogen.

Key Tuning Adjustments for Hydrogen Booster Operation

Whether you reflash the ECU or use an add-on controller, the fundamental tuning changes for running a safe and efficient hydrogen-boosted engine are similar. The goals are to lean out the fuel mixture (to take advantage of hydrogen’s combustion characteristics), adjust ignition timing (because hydrogen affects burn speed), and ensure the engine stays within safe limits. Below are the key parameters and how they should be tuned:

• Leaner Air-Fuel Ratio (AFR): With hydrogen supplementation, the engine can operate on a leaner mixture than the normal 14.7:1 gasoline stoichiometric AFR. Hydrogen gas increases the flame speed and allows stable combustion at leaner mixtures. Tuning should target a lean AFR during cruising and light loads – in practice, many tuners aim for about 16:1 to 17:1 AFR under cruise when HHO is active​

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  . This lean burn yields improved fuel economy. It’s important to implement this carefully: the ECU’s closed-loop mode will normally try to correct any deviation from 14.7:1. To achieve a leaner running condition, you might disable closed-loop feedback in those conditions or alter the O₂ sensor signal via EFIE so that the ECU “thinks” 16-17:1 is actually stoichiometric. The hydrogen ensures combustion stays smooth at these lean AFRs which would otherwise be on the edge of misfire for pure gasoline. Note: Under high load or boost (if applicable), you should not run dangerously lean – heavy throttle should still enrich to protect the engine. The lean tuning is mainly for low-load cruise where efficiency is the priority.

• Ignition Timing Retard: Hydrogen’s flame speed is about an order of magnitude faster than gasoline. This means the ignition timing needs to be retarded (later spark) to avoid the peak cylinder pressure occurring too early. If timing is not adjusted, adding hydrogen can effectively advance the combustion and potentially cause knock or rough running. A common adjustment is to retard ignition timing by a few degrees when hydrogen is present​

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  . For example, if the stock timing at 2000 RPM cruise is 30° before TDC, you might dial it back to ~25° (the exact value would be found through testing). In the HHO tuning community, it’s noted “with HHO you’ll need to reduce the ignition timing since there’s more oxygen and hydrogen and it explodes quicker”​

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  . By retarding spark, you ensure the faster-burning hydrogen-enhanced mixture doesn’t produce an overly sharp pressure spike. This also helps control NOx formation (since peak temperatures are reduced slightly by later combustion). Modern ECUs will pull timing automatically if knock is detected, but it’s better to proactively map the timing for HHO use so you’re not relying on knock sensors all the time. The end result should be smooth power delivery with no knocking – hydrogen’s high octane rating actually suppresses knock, so with proper timing, the engine should run very smoothly.

• Oxygen Sensor & Fuel Trim Management: The stock ECU’s logic will normally fight your attempts to run lean – it sees a lean AFR via the oxygen sensors and will add fuel (positive fuel trims) to compensate. To truly get the benefits of HHO, you have to circumvent this behavior. An EFIE (O₂ sensor adjuster) will add a bias to the oxygen sensor signal, effectively fooling the ECU. For instance, an EFIE can make the oxygen sensor voltage higher than it really is, tricking the ECU into thinking the mixture is richer than it is. The ECU then leans out the mixture in response​

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  . This is a clever way to maintain closed-loop operation but at a shifted set-point (leaner target). Alternatively, in a custom tune, you can simply command a lean AFR in the ECU’s tune and/or run the car in open-loop mode during cruise. Some tuners set the ECU to open-loop with a target 16:1 AFR when the HHO system is active (this can be triggered by a signal that HHO is on, if such integration is done). Additionally, modifying the MAP sensor reading is another tactic: a controller can spoof a slightly lower load reading (as if the throttle is lighter)​

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  , causing the ECU to schedule less fuel. The Intake Air Temperature (IAT) sensor can also be manipulated – making the ECU think the intake air is warmer will typically pull a bit of fuel and sometimes timing. However, be cautious with sensor spoofing: extreme values can upset engine operation. The best practice is moderate adjustments combined with proper ECU re-mapping if possible.

• Fuel Delivery and PWM Control: The hydrogen generator itself often uses a PWM (pulse-width modulator) to control current and gas production. While not an ECU parameter, it’s worth noting that tuning the HHO cell’s output is part of the overall optimization. You want enough hydrogen to gain efficiency, but not so much that it overloads the alternator (which would negate the gains). Some advanced HHO controllers tie into the vehicle speed or load and increase hydrogen production at cruise and cut it back at idle or heavy load. Ensuring the ECU and the HHO cell are in sync is important – for example, you might program the ECU to lean out only when the HHO PWM reports active hydrogen production. Devices like the ProTuner mentioned integrate the PWM control with the ECU sensor tweaks​

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  , which is ideal. For a DIY approach, you can manually set the hydrogen output to a constant safe level and tune around that.

• Engine Monitoring and Safety: It is crucial to monitor engine parameters while implementing these changes. Knock/ping: Listen for knock or use logging software to watch the knock retard. If any knock is detected at the leaner mixture, add more fuel or retard timing further. Exhaust Gas Temperature (EGT): Running lean can raise EGTs, which in excess can damage exhaust valves or the catalyst. Ideally, keep an eye on EGT if possible (some installs add an EGT gauge). Hydrogen usually results in more complete combustion earlier in the power stroke, which can actually lower exhaust temperatures at the tailpipe, but you don’t want any surprises. Coolant Temperature: Make sure the engine isn’t running hotter than normal; a slight efficiency gain might actually reduce waste heat, but monitoring ensures you catch any adverse trend. NOx emissions: A very lean hydrogen-assisted burn can increase NOx, as the combustion temperature can still be high; retarded timing helps mitigate this. From an engine safety standpoint, staying slightly on the rich side of the lean limit is a good idea – e.g. if the engine starts to misfire at 18:1, target 16-17:1 for a buffer. In one case study, a tuner experimenting with an HHO-equipped Chevy Silverado had to disable closed-loop and manually calibrate for ~17:1 AFR; he observed that the engine ran smoothly at that AFR and fuel economy improved, but he had to be careful not to lean it beyond that as it offered no further benefit​

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  . The same tuner retarded timing by about 4-5° and noted the engine ran well with no knock. These adjustments maintained engine safety while allowing the hydrogen booster to provide better mileage.

In summary, the optimal tuning setup for a hydrogen booster on a 2017 Chevy Colorado is one that leans out the fuel mixture during cruise and retards timing appropriately, while ensuring the ECU doesn’t fight these changes. Using 316L stainless electrodes in the HHO cell will maximize durability (so your hydrogen production remains consistent over time), and using either a piggyback controller or a custom ECU tune will allow the engine to actually use the hydrogen for improved efficiency. Case studies and user experiences consistently show that without tuning, HHO systems yield little to no gain (because the ECU adds extra fuel to compensate). But with the right adjustments – for example, shifting cruise AFR from 14.7 to ~16.5:1 and pulling a few degrees of timing – drivers have reported notable increases in MPG and a smooth running engine​

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. The final recommendation is to use 316L stainless steel electrodes for the electrolysis unit (for longevity and good performance) and to employ an ECU tuning solution (either a remap via HP Tuners or a dedicated HHO ECU controller) that implements lean-burn and timing control. This combination will strike the desired balance between durability and maximum hydrogen-assisted output, all while keeping the engine within safe operating limits.

Sources: Recent hydrogen electrolysis studies and HHO generator experiments; automotive engineering forums and user reports on HHO tuning (ignition timing and AFR)​

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; and expert commentary on ECU technology for fuel efficiency enhancements​

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