I love my 2004 Subaru STi for its dual personalities and spartan gagets but wish it had a "MPG computer" like the '08 Imprezas (and many other new cars) come with. I'm talking about the display that can tell you current or average mpg. Does anyone know of an aftermarket source for one? It would help in making the best gear selections for the times when I'm driving for efficiency (I can get approx. 30 mpg) rather than speed (160 mph @ about 3 mpg!)
just look around for about 5 minutes... scangauge is what everyone uses
1991 Toyota Pickup 22R-E 2.4 I4/5 speed
1990 Toyota Cressida 7M-GE 3.0 I6/5-speed manual
mechanic, carpenter, stagehand, rigger, and know-it-all smartass
"You don't get to judge me for how I fix what you break"
I think Mega Squirt can control everything on your car and it can be programmed for economy but I honestly think its best to leave your engine management system in place and start tuning for FE instead.
Water is fuel, I just don't know how to make it work yet.
SG is the quickest and easiest way. It also does a lot of other really cool stuff.
For something that will look nicer and be cheaper, see if an upscale model of your car from the same generation offers a MPG gauge, then you can get it from a junkyard and have it look stock.
For ultimate accuracy in choosing gears for a given speed, look at the DIY fuel rate monitor link in my sig. The SG doesn't have access to actual fuel rate measurement data; instead, it has to guess based on air flow and O2 sensor readings.
I use a DashDyno SPD. Besides giving fuel economy, it does data logging and 0-60 performance monitoring + lots of other stuff. I might be way better than a Scangauge, since I heard this turns off during a FAS P & G. But it's expensive at $379.