Where does the pid fuel quantity (mm3) get its data from? Would this pid be the best to monitor while trying to obtain the most fuel mileage?
EFILive logging pid's for mpg's
- Thread starter adrenaholc1
- Start date
MM3 is an reference # not an actual quantity. IMO looking at a log to try and tune for mileage is a wast of time.
I'm not logging. I'm watching parameters in real time while driving to try and learn how rpms, boost, rp, pw, *, etc. affect mileage.
I'm not logging. I'm watching parameters in real time while driving to try and learn how rpms, boost, rp, pw, *, etc. affect mileage.
Still a wast of time IMO its to small of test to get any real info. I've tracked my mileage on long trips switching tunes between tanks fulls and still don't always get a consensuses. The best is to keep detailed records over months or if you do the same 60+mile round trip on a regular bases try a different tune each time. Keeping in mind how weather and road conditions are going to affect the results.
Now looking as a log to see what areas of RPM, Timing, Boost, RP, and PW you need to change to affect mileage under normal driving conditions is a must.
Now looking as a log to see what areas of RPM, Timing, Boost, RP, and PW you need to change to affect mileage under normal driving conditions is a must.
GMC_2002_Dmax
The Still Master
I get this question all the time because of the cost of fuel and everyone tries to stretch the fuel out as far as they can.
If you ask a salesman he will tell you what you want to hear, if you ask an honest person they will tell you the truth.
The honest truth is it will take "X" amount of fuel to move "Y" amount of weight at "Z" speed.
So the answer is keep your foot light as an egg on the pedal, advance the timing and try to avoid jack rabbit starts and hard acceleration, short of doing that and driving like an old lady to church you can expect anywhere from 17-22 mpg/LB7, 15-19 mpg/LLY, 18-24 mpg/LBZ and 12-18 mpg/LMM.
Unless you have a 950 lb plow and a 800 lb sander/w 2000 lbs of salt then expect 5-8 mpg with an LBZ........
BTW,
Merry Christmas
:thumb:
If you ask a salesman he will tell you what you want to hear, if you ask an honest person they will tell you the truth.
The honest truth is it will take "X" amount of fuel to move "Y" amount of weight at "Z" speed.
So the answer is keep your foot light as an egg on the pedal, advance the timing and try to avoid jack rabbit starts and hard acceleration, short of doing that and driving like an old lady to church you can expect anywhere from 17-22 mpg/LB7, 15-19 mpg/LLY, 18-24 mpg/LBZ and 12-18 mpg/LMM.
Unless you have a 950 lb plow and a 800 lb sander/w 2000 lbs of salt then expect 5-8 mpg with an LBZ........
BTW,
Merry Christmas
:thumb:
Thanks for the replies fellas. I guess what im really trying to figure out actually has more to do with shift points. With the bigger charger it seems like it lugs and uses more fuel (shown by increase in pw,mm3.) rather than downshifting to get back on the charger a little more. I think the best way to phrase my question is: if mm3 is at 38@1500rpm in 6th@60mph and i drop to 5th mm3 drops to 29@1900rpm@60mph does that mean im using less fuel or does the increase in rp offset this? Also I assumed that a little boost would help at cruising speed (mine=5psi) unless the amount of fuel to maintain that boost means less mpg. then theres always vane pos. I understand that there are hundreds of variables when trying to figure this stuff out it just seems like I could make better mpg between 1000 and 2000 rpms. Is there a way to shut down cyl's at speed that would be sweet. :thumb:Thanks again for any feedback. I love reading your theories and hope you all had a wonderfull xmas. I got some gearwrenches and husky floor liners:woott:
. Is there a way to shut down cyl's at speed that would be sweet. :thumb:Thanks again for any feedback. I love reading your theories and hope you all had a wonderfull xmas. I got some gearwrenches and husky floor liners:woott:
You can do the math to see.
4 (number of event cycles per RPM) * mm^3 (Volume per cycle) * rpm = mm^3 per minute
4*38*1500=228,000 mm^3 per minute
4*29*1900=220,400 mm^3 per minute
You might try upping the speed slightly to see if the engine gets into the power band increasing efficiency.
4 (number of event cycles per RPM) * mm^3 (Volume per cycle) * rpm = mm^3 per minute
4*38*1500=228,000 mm^3 per minute
4*29*1900=220,400 mm^3 per minute
You might try upping the speed slightly to see if the engine gets into the power band increasing efficiency.
sweet formula, thanks. I'll have to get more accurate data and try this on level ground. or i also could log mm3 and rpm for say 5 miles in 6th gear then try the same 5 mile route in fifth gear and check the hi/lo/avg in the log.
IMO, you are on the right track.
Boost is another question that I’m exploring after reading some opinions that lower (1-2 PSI) is better for mileage.
It’s a little complicated but even at low commanded boost levels, my vane position (as controlled by the ECM) is high resulting in associated drive pressure that I think could be detrimental.
So, in cruise conditions < 50mm3, I’ve programmed vane position such that drive pressure is very low and boost is where I want it.
I’m waiting for a long enough trip to get test results.
One thing for sure, it will be hard to go back to the constant whistle going down the road. The current setup sounds awesome – deep exhaust note just cruising and a very faint whistle that gets louder as the vanes close > 50 mm3.
Boost is another question that I’m exploring after reading some opinions that lower (1-2 PSI) is better for mileage.
It’s a little complicated but even at low commanded boost levels, my vane position (as controlled by the ECM) is high resulting in associated drive pressure that I think could be detrimental.
So, in cruise conditions < 50mm3, I’ve programmed vane position such that drive pressure is very low and boost is where I want it.
I’m waiting for a long enough trip to get test results.
One thing for sure, it will be hard to go back to the constant whistle going down the road. The current setup sounds awesome – deep exhaust note just cruising and a very faint whistle that gets louder as the vanes close > 50 mm3.
I need a dp gauge for sure. From the little driving I did today with the turbo vane inoperative at 0% I noticed the mileage in town seemed better light to light but at higher speeds it was terrible cause the charger wouldn't spool at all when on a grade and the egts were cooking around 1100 I'm really curious about setting that vane pos to 10% below say 40mm3. I think there is a fine line where the vane could be open at light throttle to reduce back pressure then close to build a few psi when load requires. I think I said that right