I know this is pretty widely known but I figured I would post it as reference for anyone who is not familiar with this trick. If your mazda 3 did not come with a trip computer, you can use these instructions to unlock it. http://www.mazda3club.com/showthread.php?t=44448
I will warn you. I have found my trip computer to be a couple MPG off, my FE is actually higher than the trip computer reads. So, keep track of your gas and miles to be sure. The instant fuel economy is useful.
Yes, not too accurate - especially when it comes to guaging the distance to go on the amount of gas in the tank. It will say I can only go another 10 or 15 miles and when I fill up I'll get barely 12 gallons in a 14.5 gallon tank. I'd rather it be wrong that way. Overall it's still nice to see the instant mpg though.
Mine reads over all 1.5 to 3 mpg low. And miles remaining is not good either. When mine says no miles left Ive got 50 miles or better left depending how Ive driven that tank over all. So I do use the hacked DIS in my MZ3 and the SG1 has been put in the Accord.
I tried this technique on the rental car that I have (single cd changer) and it did not work. Thoughts?
What year is the car? I believe it only works on 06 - 07 Mazda 3's. Mazda disabled it (or at least made it impossible to hack) for 08.
that's too bad that they "fixed" it for '08. When I got it going from the other forum about a year or so ago, it took a couple of tries before it kicked in. If it reads a lower mpg, then mine must be REALLY good since I get 34.3 mpg according to the computer. Maybe I really 36!
Forgive my ignorance but what exactly does this trip computer hack do? I know that my '06 3 has those MPG settings like average MPG, instant MPG, and I can't remember the others so what specific features does this hack do? I've looked at the average MPG thing but I never knew how to reset it or something so that I could see how accurate it is with each new tank of gas. The instant MPG thing is kinda neat but fluctuates dramatically - to the point where I have a hard time believing what it is saying. Sorry for the thread resurrection.
On most models of the MZ3 the DIS/MPG meter are turned off. There is a button hack one can do to make it come on. All you need to do to reset the thing is hold down the set button, of course with the car booted up. The instant mpg read out will move around. You can use the instant mpg read out to see what your getting pulling a hill or on level ground steady load and speed. Its your near real time mpg read out. And it does not update fast enough for me.
