I'm at wits end with trying to squeeze as much mileage out of my 4.0 as possible. Being a college student, the constantly rising gas prices are starting to bite, and at the same time I don't want to sell my XJ because not only does it have so much value to me but also because here in VA a good SUV or truck is nice to have, especially during winter.

So far I've done the CAI upgrade, the Neon Injector upgrade, the electric fan upgrade, and I'm always keeping my engine in stop shape with oil changes, fuel system cleaners, etc. I think I have maxed at about 23-25 mpg highway with my mods.

Now, to my question. Has anyone heard of these hydrogen generator things for cars? Supposedly they're supply-on-demind types that deliever a constant stream of HHO to the intake and have a nice increase in mileage. Any ever used one? Thanks for any input.

 

I've seen crazy good results for them on Diesels but i havent seen anything with the 4L yet.

at 23-25mpg you're not likely to get much better.

As for gas prices, let me know when you're paying what we pay for gas up here. We WISH we had the gas prices you guys have. If I paid what you paid I'd be driving a 1955 V8 Cadillac with 150 lbs of bricks in the back just because I can. lol

 

I wanna know to but for my dd

 

25mpg? How do you manage that? I wish I had my 18mpg back..... I just got back from Ohio where gas was $3.29 and I was averaging 13mpg higway.

 

With everything stock I got about 20 mpg highway and around 15 in the city (these were the values online as well as what I got from driving and checking the odometer). After the mods, I rechecked my values and came up with this result.

 

Its been a long road of testing and guessing. This gen is making 1 ltr/min. So far, so good.

 

That is awesome! Have you noticed any good results? I mean, I am nowhere near expecting a miracle gain of like 50% mileage. I think those "GAIN 70 MPG" things are a joke, but anything small is better than nothing at all.

 

This is a 92 AT daily driven as my service vehicle and tows my little popup camper in the summer. Currently this install only has 200 miles on it. Nothing to brag about yet.

BTW whats a CAI mod?

 

Cold air intake

 

Cold Air Intake. I utilized the stock air box as a heat shield, enlarged the opening behind the headlight with a larger metal tube, and made a filter similair to yours connect to the stock throttle body pipe through the air box. Works well, and since I don't off-road with my Jeep I dont worry about mud or anything. I go on the occasional mud trip or play around in the snow, but I have had no issues as of yet.

The reason I asked how yours held is because I think I read somewhere that an engine similair to the Jeep 4.0 requires 2 L/M to get results. If yours held well I was gonna use a design I found online that produces app. 2.3 L/M.

 

Fact:

Increasing the load on your alternator by imposing a direct short through a brine will not under any circumstances, produce enough H2 to make up for the friction and drag losses incurred by the added load.

If you have a system like on my Buell that uses a voltage regulator to modulate your electrical system by turning excess power into heat, then you have a slightly better chance of outsmarting the laws of physics, but it's still improbable.

Automotive alternators make power as called upon by load. More power required, more load applied and more power generated up to the limit of the alternator. They do not generate "waste" electricity without costing you drag, and therefore lowering your fuel economy.

 

There has been debates on just how much a cell can affect mileage gains from amp draw. Here's a formula to calculate how much horsepower you're losing.

How much horsepower does an alternator pull ? You can mathematically determine the horsepower cost at any given load. (Alternators respond to load. If there is no load present the alternator is basically freewheeling.)


Amps x Volts = Watts
Watts / 745.7 (one HP) = Electrical HP Produced by the Alternator
HP x 15% Efficiency Loss = HP Loss
HP + HP Loss = Total HP Used


Example:
57A x 14.9V = 849.3 Watts
849.3 Watts / 745.7 = 1.14 HP
1.14 HP x 15% = 0.17 HP
1.14 + 0.17 = 1.31 HP Total

The loss is really minimal. You may see a 1-1.5MPG loss depending on how much load the alternator will see with the system. Whether this type of system produces enough extra mpg to make up for the losses? I dunno.

 

The error in thinking is that the alternator is always producing a constant output of electricity which is otherwise going to waste.

This is incorrect. An alternator responds to the load which is placed upon it by increasing the load on the engine to produce more juice. It essentially "robs" power from the engine.

Due to inefficiencies inherent in any mechanical system (ie friction, electrical line loss, environmental loss) the power produced will always be less than that consumed.

The bottom line is that there will be a net loss of mileage, albeit small. Due to various driving conditions and environmental changes this may go unnoticed.

 

A few current pics

[IMG]http://carphotos.cardomain.com/ride_...4004_large.jpg[/IMG]

[IMG]http://carphotos.cardomain.com/ride_...4010_large.jpg[/IMG]

[IMG]http://carphotos.cardomain.com/ride_...4012_large.jpg[/IMG]

[IMG]http://carphotos.cardomain.com/ride_...4004_large.jpg[/IMG]

 

I've read about hydrogen generators and been curious about the effect they would have on fuel economy.

Thinking that the throttle body is rated for approx. 400 CFM and assuming that in normal operation maybe 25% of that 400 CFM is actually utilized, hydrogen production of 1 liter/minute doesn't seem like it would amount to much of anything.

I'd have to see some real world MPG testing before I'd invest in this system.