Originally Posted By: mikered30
How do you use IGN? What are good numbers too look for?
This probably varies from car to car, but the IGN tends to range between 7-40. Generally, the more advanced the timing (which shows as a higher IGN), the more fuel efficiently it is running. With an auto, it takes some playing around on the highway to get the hang of it, but once I hit the merge I use the throttle and the RPM readout to hunt for the sweet spot (when I approach 30 on the IGN I'm getting close to it). Once I've found it, the 4 speed auto is in 4th and turning about 2200-2400 RPM.
When IGN is in the 35-40 range, the car is in the zone: its getting optimal fuel economy as confirmed by the mileage readout, which'll give 40+ mpg (or under 6L/100 km as my display is metric).
Knowing that higher IGN is better, once I found the range on mine, it became the key (with the help of the other settings) to getting optimal mileage at a given speed range. That's the only part of the Scangauge I've mastered pretty well (and quickly), with the help of the feedback from the other displays.
IGN is harder to use in the city because you don't have time to find that same zone before you come to a light, etc.
LOD is supposed to be more helpful there, but that one is harder to master. For city, I'm still mostly reliant on the other 3 gauges as I try and use the LOD.
Different principles for both: with IGN you want to find your range and figure out how to move into it the highest part as fast as possible and maintain it as much as you can.
With LOD, you are using it to accelerate to the target speed as quickly as possible, such that once you hit it, and let off on the gas, the auto will up shift and you'll only be turning 1,500 or 1,600 RPM. Or on a manual, you use it to time the shift yourself to achieve the same end.
These gauges are largely how hyper-milers can beat the EPA rating by 150% and more. Although they also use some techniques that I just don't subscribe to: like coasting engine off on hills or up to lights. I like saving money on gas, but there are limits I'll go to that end. Mostly I'm achieving my best results by simple weight reduction (not toting a trunk full of junk around), some modified driving habits (mainly in them being less aggressive, which is also good for minimizing wear on brakes and such), and feedback from the Scangauge.
-Spyder