MPG 4bar FPR vs 5 bar FPR
09-25-2003, 12:08 PM
#1
Audiworld Junior Member
Thread Starter
Join Date: May 2003
Posts: 54
Likes: 0
Received 0 Likes
on
0 Posts
MPG 4bar FPR vs 5 bar FPR
X Post from Vag-Com Forum
Has anybody reprogrammed the trip computer to adjust for using the 5 bar FPR. I'm pretty sure that the fuel consumption calculation uses injector duty cycle at an assumed pressure, increasing the pressure would underestimate the fuel consumption and the MPG. How much is my question. I thought there was a way to change the mpg calculator on trip computer within a +/- 15% range. My manual calculations comparing the computer calculation to miles driven between fill ups, comes to 26.3 (computer) to 23.8 (manual), about a 10.5% overstatement if my manual calculation is correct. With the 25% greater flow pressure between a 4 bar and a 5 bar, I had expected it to be more like 25% difference. I realize neither of the FPRs flow full pressure at all times. Is it possible the GIAC chip already took this into account?
Has anybody reprogrammed the trip computer to adjust for using the 5 bar FPR. I'm pretty sure that the fuel consumption calculation uses injector duty cycle at an assumed pressure, increasing the pressure would underestimate the fuel consumption and the MPG. How much is my question. I thought there was a way to change the mpg calculator on trip computer within a +/- 15% range. My manual calculations comparing the computer calculation to miles driven between fill ups, comes to 26.3 (computer) to 23.8 (manual), about a 10.5% overstatement if my manual calculation is correct. With the 25% greater flow pressure between a 4 bar and a 5 bar, I had expected it to be more like 25% difference. I realize neither of the FPRs flow full pressure at all times. Is it possible the GIAC chip already took this into account?
Thread
Thread Starter
Forum
Replies
Last Post
kday
Audi Original "S" Cars
9
04-30-2008 08:24 AM
Casey
2.7T V6 Discussion
1
04-06-2005 12:15 AM
