Aftermarket Retrofit Device Evaluation Program | Cars and Light Trucks | US EPA

Haven't gotten through the bulk of them and to be honest not really sure if what I'm looking at is even applicable to Honda Fit engines.

But it seems they have conducted a substantial amount of testing on various devices and additives that claim to do everything from increase fuel economy to decreasing emissions.

Anyone make heads or tails of anything here?

 

hi,

It's amazing that this thread doesn't get any responses. This is such a useful topic.

Honestly, I don't believe in any aftermarkets products increasing fuel economy, even if they do, it makes very little difference. Example is some types of premium performance air filter or premium fuel, they are proven to only work on high performance cars and may even decrease performance on smaller cars - source mightycarmods videos and some some credible UK car review teams videos on youtube. The reason I use these examples are because they are the 'real' stuff that your engine use, let alone the other stuff that doesn't even exist on your engine yet. Like something that filter your fuel again before it goes through the 'real' fuel filter etc.

I prefer to keep everything to stock and getting genuine manufacturer parts for my diy services.

So my point is no for devices or additives. However, I still use fuel additives on my car and my reason is for it to clean the fuel injectors, or fuel systems. Of course, I won't trust the claims of 'increase fuel economy' written on the bottle (I heard cases where it worsen fuel economy because fuel injectors now inject more fuel - better than injecting no fuel at all). I do trust that fuel injectors inside the engine needs cleaning once in a while for it to work properly, similar to changing oil, replacing spark plugs etc

That's my take on this topic, would love to hear other's opinions.

 

The EPA lacks credibility in many cases not the least of which is claiming our late model Hondas can use 15% ethanol when the manufacturer says otherwise. When it messes up the fuel system and Honda won't cover the repair under warranty who you going to look to for relief? The EPA? Good luck with that.
On the topic of mileage enhancers, I agree with the poster above in that they probably don't work and the best you can do is keep the stock system clean and maintained.

 

I am also highly skeptical of most additives, esp related to economy. FWIW, Lucas octane booster does seems to work as advertised (not that we need to use it). I've heard new special oils like 0w-20 (or Royal Purple) can reduce friction and give slight economy gains, but those are only to be used in engines originally designed for things like that (or race engines with a limited lifespan anyways).