My friend (NOFX) just bought an HF CRX and she let me drive it yesterday. This is probably a question that won't perk anyone elses interest but it makes me curious. How does the economy indicator light work? I thought it was just a simple light that came on when the car hit a certain speed...but it seems a little more complicated than that. It seems like it could be based off of TPS or something along those lines. At lower throttle the light comes on at lower rpms, but when you step on it a little more, the light will go off and then come back on at a higher rpm. Is it tied in with the ecu? Just curious if anyone actually knows.

 

Talking about the shift indicator, right?

I believe its based on RPMS, but I could be completely wrong. Only an assumption.

My Crx HF didn't come with the indicator since its from Cali (cali didn't come with it)
My Crx HF from Texas DOES have the indicator, but its up on jack stands after purchasing it. So I haven't had an opportunity to see how it works yet.

 

the ecu looks at a number of things, including speed, load (vacuum), throttle position and maybe more. then it determines when is the best time to shift to maintain current speed and increase fuel economy. that's why when you go slow, it comes on sooner, when you're driving harder, it waits to come on.
any car with a 'shift' light works this way, not just hondas.

 

Yea, it can't be totally based on rpms because when its under a different load it changes. Thanks for the input. Didn't realize that the "economy driving indicator" of an '88 crx would have that much thought and technology put into it. I realize whar the ecu does, i just didn't think honda would have actually put that much work into it. That's really cool.

 

When I get a shop manual and ETM I'll have to let you fish through it to see if we can get a better idea of how it works.

 

Just goes to show they were ahead of their time. Don't some newer cars and hybrids have a light that comes on when cars are being drive efficiently? People make a big deal about that nowadays, but really it's nothing new.

 

Yea...newer cars do have the shift lights. Sadly the 22 year old hf is getting better mileage than a new insight. Haha

 

I agree, unfortunately new cars are just so heavy because of all the safety requirements, airbags and whatnot. It's nice to be safe, but it sure isn't cheaper or more efficient than how things used to be with small lightweights like the HF and the Chevy Sprints or Ford Festivas.

 

or the geo metro, those arent bad for milage if you can find one that was took care of