Ever since I installed my 650cc's my fuel mileage meter and distance to empty meter on my car has been way off (43 mpg, 540 mile on a full tank, etc...)...I actually average closer to 19 mpg at about 340 miles/tank

My tuner told me that the fuel mileage/dte meter was calibrated to run with the stock injectors so that's why they're way off....

So that being said is there any way to recalibrate the fuel mileage/dte meter or fix it so it reads the proper mileage/dte?

 

I don't think that's right. I'm running 630cc inj and my gauge reads fine. If I'm not mistaken the sensors in the tank mess up all the time. It may need to be replaced.

See here...
https://my350z.com/forum/forced-indu...ge-issues.html

 

i assume its the same setup (different display) as the G's.

It is a vaccuum gauge basically that does some calculations based on vacuum, throttle position, speed, etc.
So when you go into positive boost it pegs off the chart (i.e. great mileage 40+) which is way wrong........and now that I did the 3.3diff in the 6spd it shows 60+ on the highway lol, and my miles till empty almost never drops below 300miles lol.

tom

 

SO I guess there's nothing that can be done about it?

 

No clue.....I know mine is waaaaay off.....

I just assume a certain mpg depending on my driving style...hasn't let me down yet

Plus when at some higher power numbers you don't want fuel level too low anyway...easy way to go lean on accident......so just fill up sooner

tom

 

Mine is way off as well ('04 G35 coupe). I've always assumed the calculations are based off of IPW at stock fuel pressure.

Besides somehow adding a scaling map to the OEM ECU I don't see any way of fixing the isssue.

 

Well...I'll try and call Performance Nissan in Duarte about it, since they are about as friendly to aftermarket/FI setups as you can get in Nissan Dealerships and I know one of the techs there really well, and see if there is anything they can do to fix such things....

If not, it's really not a big deal...FI is worth it...

 

I thought it was because the o2 sensors were pulled back with the non fouler bungs that are used to fool the stock computer since the cats are removed. This makes the computer think its running much leaner hence the much higher mpg. You can always record your miles and fill up and calculate your mileage the old fashioned way. I personally could care less how many mpg's I'm getting with my FI'ed Z.