Built-in MPG calculators - Is yours as much of a liar as mine?

[slurp812]

My scangauge II is great, if I am super light on the throttle. If I hammer it, its WAY off. It might be that I have a weird ECU also, its a 2002 civic Si.

[whitevette]

Originally Posted by slurp812

My scangauge II is great, if I am super light on the throttle. If I hammer it, its WAY off. It might be that I have a weird ECU also, its a 2002 civic Si.

If you mean "stable" numbers by your term "great" (when you are light on the throttle) and "moving numbers" when you hammer the gas - do you expect the numbers to be steady in their rapid decline and climbs? Remember, this is a digital device...any changes in input ( voltage ) are gonna jerk these numbers around ; ie , a sudden change in a non-digital parameter is going to be reflected in a flashing, jumping digit. And ... pumping the gas / brake pedals drink gas! Perhaps your SC is merely trying to keep up?

Myself, I prefer the analog meter ( with a rotating needle & a numbers
scale ), where the RATE OF CHANGE of the needle gives an indication of what is happening. Digital numbers, on the other hand, cannot reflect the RATE of change ... they skip around and run like a peg leg track star. The tenths go crazy...getting in each other's way as they try to settle down; ie, there is no such thing as "sweep" on a flashing digital display.

Welcome to the 21st century...where bean counters rule. Analog ain't cheap. Chip circuits & LED / whatever these black numbers you cannot see sometimes ... are cookie cutter cheap to make ( not necessarily to buy).

Then, there is always the possibility your SG is more correct than your "butt dyno"....

[slurp812]

Originally Posted by whitevette

If you mean "stable" numbers by your term "great" (when you are light on the throttle) and "moving numbers" when you hammer the gas - do you expect the numbers to be steady in their rapid decline and climbs? Remember, this is a digital device...any changes in input ( voltage ) are gonna jerk these numbers around ; ie , a sudden change in a non-digital parameter is going to be reflected in a flashing, jumping digit. And ... pumping the gas / brake pedals drink gas! Perhaps your SC is merely trying to keep up?

Myself, I prefer the analog meter ( with a rotating needle & a numbers
scale ), where the RATE OF CHANGE of the needle gives an indication of what is happening. Digital numbers, on the other hand, cannot reflect the RATE of change ... they skip around and run like a peg leg track star. The tenths go crazy...getting in each other's way as they try to settle down; ie, there is no such thing as "sweep" on a flashing digital display.

Welcome to the 21st century...where bean counters rule. Analog ain't cheap. Chip circuits & LED / whatever these black numbers you cannot see sometimes ... are cookie cutter cheap to make ( not necessarily to buy).

Then, there is always the possibility your SG is more correct than your "butt dyno"....

I mean if I drive nice, the Scangauge is real close to actual mileage. If I drive with my foot in it, it is WAY off, like 5-7 mpg for the tank, or more. It doesn't seem to "catch" me with my foot in it enough. it should read less when I am heavy in the throttle.

[jsl4980]

The mpg gauge in my Hyundai Tucson is always dead on. I reset the mpg gauge and odometer every tank and do my calculations at every fill up. Its never been off by more than .3 or .4.
Make sure to read up on your built-in gauge. Most of them only measure over a certain amount of miles, instead of the entire time since the last reset.