Real-time MPG display on an older car

A new post has been added to the Macchina blog: Real-time MPG display on an older car

Comment on it below.


Its nice to see the older protocols still in action. Everything being CAN now, you dont see many projects based on old legacy busses.

Now if only there were J1850VPW libraries available. :confused: :cry:


If I could get my LAB working… :sob:

Spooling up to do some other stuff with my M2 but J1850 might be more of a winter break project at this point… Still tinkering with my lab trying different things to get it working but haven’t quite gotten it going yet. Real busy through the end of the month then finals so after that hopefully I can get some stuff done…

Also want to integrate any protocols such as LIN into m2ret and build a universal driver so it can be accessed via a standard ELM or STN program… (At this point the ELM/STN support will likely be build while doing the universal driver because I sort of need both working together.)


Thanks for doing a quick and simple project for older cars (I have a RAV4 2004) as I suspect most macchina owners are in a similar situation. Just ordered the NeoPixel so will set it up next weekend.

I REALLY like what you did! I just recently bought a 1989 Mercedes Benz and it actually has a eco gas gauge on it. I found it interesting that first that old of a car would have one, but more would actually make a difference and have any accuracy. Putting the car to the MPG test I discovered the same thing as you when yours got to red. If I slightly let off the accelerator I would go back into eco with barely any change in speed. To see a LED gauge that you could have the power to go back into green as I could get the gauge out of red and in the white line of eco and not change much speed, I like yours A LOT more! :slight_smile: I do not like how on some of my friends new cars you do not get to see the change between their cars telling them they are just no longer in eco drive without showing you have surpassed that and at what speed. I also found by putting Car Boss in my oil I actually am still almost getting 33 MPG in this 89 car. I love the LED in compared to a needle gauge!