I want to make an MPG display for my motorbike. Unlike most modern cars it doesn’t have an OBD-II system, so I need to measure the fuel flow directly. I remember reading that SparkFun sold a fluid flow sensor but I can’t find it now, but I also thought it couldn’t do petrol.
Anyone know of a sensor that would be able to measure the flowrate of petrol?
I don’t think Sparkfun has ever carried it. It’s not spec’d for gasoline; in fact, it doesn’t seem to be spec’d for anything other than water, but you can try it. I have a couple and they work very well, but at 1 liter/minute minimum flow rate, it’s too high for a motorcycle. Maybe if you were running a 16-cylinder diesel it would work
Two things Id like to input: First, if you tamper with or add anything into the fuel line, make sure it is safe to do so and legal to do it! If you go and get an inspection with this gadget in there, they might (might!) fail you.
Second is, I found plenty of cheap flow meters on ebay (http://r.ebay.com/NhyieE), but as this deals with fuel and potentially your life, I wouldnt go cheap, and I wouldnt do this myself. Find yourself a good mechanic who would be willing to take the job, and invest in some reliable technology to get the job done right, and not just on the cheap.