What calculates the MPG display? + Instant MPG

[LS1GTP]

Curious to know how the car knows the MPG it's getting. Is it from the PCM?

I was wondering if I could mod it to read instant MPG, and if anyone has done it before. Did a search with no luck.

 

[Fivefingerdeathpunch]

Yeah its a instant reading.

On a Aeroforce scan gauge there is a Instant MPG option to view, its the same thing the DIC uses to figure out mpgs and give you a rough avg of what you are getting.

Not sure if its even possible to make it read instant, but who knows.

 

[Tony Mendez]

Typically it's a calculation based on PCM inputs... Engine load, TPS, VSS, etc.

 

[Scottydoggs]

buy a regal, its got instant mpg....:th_winking:

some how im sure it works off the engines vacuum.

 

[addzradd]

I was under the impression that it was injector duty x rpm/ mph.

 

[nos4blood70]

Bonnevilles have instant too.

I'm thinking it uses the MAF sensor.

 

[LS1GTP]

You're probably all correct, lol. Kinda figured it was a stretch.

 

[Timing]

the joys of having an 04 i have instant and average

 

[Fivefingerdeathpunch]

On 04+ only the 5 button DIC has it.

 

[Timing]

yay for me

 

[dazedandconfused]

I was just wondering this very thing today. For a 16 year old car I'm surprised how close my dic reads the avg fuel economy. Its consistently between .5-.8 mpg hand calculated when compared to the dic

Sent from my DROID RAZR HD

 

[coolone]

Make sure your speedo is set correctly... I'm sure that figures in to the equation!
just sayin...