Has anyone used a Fuel Save Pro chip??

I was watching some videos from GRM and one of the adds was for a gas saving chip you can purchase. fuelsavepro-chip.com

Does it work or just BS? Why not ask the GRM Hive?

Heard of it. It was declared a scam IIRC. 

Complete and utter bullE36 M3. 

Let's see how many red flags I can find on their site.

Claims Big Oil is trying to suppress them - check.

Claims it works with just about any car - check. Compare to how many cars a large reputable tuning shop like Cobb or HP Tuners has figured out how to tune. These guys have gotten even lazier and not bothered pretending they have different models or programs for every model they support - it's one device that can reprogram any OBD2 ECU! And costs only $50!

It works if you want to add a blinking LED to your OBD2 port.

Sounds like the 2022 version of the Fish Carburetor.

My first thought was that it was a hydrogen generator, but a magic computer box is so much better.

BigClive on YouTube is a Scottish gentleman who breaks down electronic gadgets and reverse engineers them. These OBD fuel savers are just an LED light show

They clearly can't be anything else. OBD-II is not a programming protocol. That port is a way to query the status of the On-Board Diagnostics system. Sure, it's also been adopted as a common port design that can be used to connect to other systems, but that's neither a given nor standardized. 

But it has power, so it's perfect to run an LED. 

Next they'll be selling magnets for the fuel line...

Well the algorithm chooses where to play the commercials on YouTube. If there are videos that contradict the commercial I would think that YouTube would not run the commercial. 

Australia's Peter Brock (not the Cobra guy, the King of the Mountain) went from hero to zero in large part due to a "fuel polarizer" he was hawking. 

MyMiatas said:

Well the algorithm chooses where to play the commercials on YouTube. If there are videos that contradict the commercial I would think that YouTube would not run the commercial. 

Ha ha ha ha ha ha ha ha ha ha ha ha

Every time I see these devices being hawked, I get the impression that I'm just not unscrupulous enough to try hustle for piles of money or something.

One German computer magazine did actually "test" a bunch of these devices and the only positive thing seemed to be that they have less impact on fuel consumption than the "power chips" that contain a resistor to try and convince the ECU that the engine is cold. Plus, you can pick the LED color thanks to the choice of devices.

03Panther said:

Next they'll be selling magnets for the fuel line...

Came here to mention magnets, but knew in my heart it had already been said...

I came here expecting grm to deliver, and they did not disappoint. 

03Panther said:

Next they'll be selling magnets for the fuel line...

I’ve discussed that with our fuel expert to see if there’s any kernel of science in there. IIRC, I got a big ole nope from him. (I had to ask of course, though.)

Wasn't it possible to reflash the ecu of diesels - and maybe gas(?) too - to adjust the fuel/air ratio, and that legitimately could give better gas mileage?

I bet that would wreak havoc with the emissions systems long term. But these are probably selling on the hope that people have no idea what is required for a reflash. 

mtn said:

Wasn't it possible to reflash the ecu of diesels - and maybe gas(?) too - to adjust the fuel/air ratio, and that legitimately could give better gas mileage?

I bet that would wreak havoc with the emissions systems long term. But these are probably selling on the hope that people have no idea what is required for a reflash. 

Yes. For a gasoline engine, it would give you a massive spike in various nitrogen oxide emissions immediately; long term the higher exhaust gas temperature could damage the catalytic converter. The EPA would not be amused. You might be able to get around some of the downsides with water injection.

Diesel engines already back down air fuel ratios a lot at light throttle. Boosting mileage there would require adjusting fuel timing instead. I don't know enough about their tuning to have a clear picture of the consequences.

MadScientistMatt said:

mtn said:

Wasn't it possible to reflash the ecu of diesels - and maybe gas(?) too - to adjust the fuel/air ratio, and that legitimately could give better gas mileage?

I bet that would wreak havoc with the emissions systems long term. But these are probably selling on the hope that people have no idea what is required for a reflash. 

Yes. For a gasoline engine, it would give you a massive spike in various nitrogen oxide emissions immediately; long term the higher exhaust gas temperature could damage the catalytic converter. The EPA would not be amused. You might be able to get around some of the downsides with water injection.

Diesel engines already back down air fuel ratios a lot at light throttle. Boosting mileage there would require adjusting fuel timing instead. I don't know enough about their tuning to have a clear picture of the consequences.

Diesels don't require a throttle (although it can be used to reduce certain emissions). They can run at virtually any lean ratio and most rich ones, whereas gas can only be spark-ignited in a relatively  narrow window. Diesels are idling with the same airflow they get at WOT (at the same rpm) when they are unthrottled, so they control idle speed by just giving it tiny drops of fuel. Fuel timing in diesels is really neat; it is done both for reducing noise and for spreading the cylinder pressures out more evenly because they are getting multiple, smaller injections. I think 8 injections per cycle is the most I have personally seen. For diesels, fuel=torque; you can't just lean them out at a given torque demand or else you'll slow down. There may be some tweaks you can do here and there (like timing and quantity of injections), but AFR isn't the way to go. Heck, the ECU code can just take pedal position -> torque request -> fuel quantity.