So, the car now gets 30 MPG on the highway.

2004 MT, Pettit Engine, was AP tuned and getting 25 MPG. I had to pull the AP tune because it is going into the dealer to troubleshoot a 610 error. I have a set of D585 coils. It is not the change in the dwell table because my dumb self seems to not have the new dwell map installed.

In the cruise range, 3,500 RPM and .40 Load, the fuel tables are identical between what I think is stock and my tune (Lambda =1). Timing is identical. Dwell is identical. MAF is scaled a bit, VE changes are very minor, only a few percent here and there. All the other tables are the same. MPG is measured on my Ultra Gauge, and the rate the gas gauge is going down mimics the found MPG.

My tune had a LTFT in this range of about 0 (MAF, Injector 1, VE). The factory tune has an LTFT of about +10. Load is about .35 at cruise, same as before, 0.39 with the AC on. All the other tables are identical with one exception, OMP.

My tune apparently has 6X more OMP flow at this point (3 stock vs. 18) and I premix half an ounce to a gallon. Yeah, I am not sure why I did that, I meant to make my changes outside of the cruise zone and let pre-mix take care of that area. I will back it out and test once I run through the new ECU protocol.

The question, can the extra oil account for that big a change in MPG, or is something else going on?

Thanks,

 

How are you measuring this?

The measurement methodology will probably hold the answer.

 

No way.

 

It's like when dying people suddenly appear to be doing better right before dying.

Be afraid, be very afraid.

 

Thanks BigCajun, I appreciate the kind thoughts.

Measuring by Ultra Gauge. It sits on the diag port. But, needle is going down slower on the gas gauge as well. I will know more at the next fill up.

Best I got so far is the brain dead oil rates I had set up.

 

Get a couple tanks through it, calculated mpg's manually....

 

I'm just messing with you.

 

With all that oil, the ECU probably figured you don't need fuel. Add more, eventually you won't burn any gas at all :P

 

That gauge isn't accurate. There is no way you are getting 30MPG. I did some hypermiling of my own years back on the 5 hour round trips (straight up I-35 70MPH) to my parents and the best I got running it to damn near empty was 24.9MPG and 358 miles to one tank. My car was stock at the time with a fresh engine. Just for comparison my GF had a 2010 Mazda 3 at that time and the best I got was 31MPG. She also had a Juke that I managed to get 33MPG on the same trip in ECO mode. Her CX-5 is lucky to get 24MPG. My 335i's best has been 22MPG.

 

I am tracking the gauge the same way I have been tracking it for the the past 10 months, and with Brandy for 5 years before that. Gas gauge needle is still covering the little pump symbol, am just over 200 miles. The new route to work has a lot of 55 mph driving. 65 MPH is down around 27 indicated.

Plan on filling up today or tomorrow to check things out. Driving by odometer for now. Car was down 1/4 tank when I switched tunes.

I think what I have going on is evidence of how well the oil soaks up heat in the combustion chamber. And, this is an injector set I re-scaled, but only a few percent. That may be a part of the number, but again, not much.

More tomorrow.

 

All is wellish...

Drive home from work, first half mile, gas gauge dropped almost a quarter tank. Ultra Gauge is still hosed. Not going to worry about it for now. She goes in for the 610 work on Thursday. But the high MPG was a lie. 9K was right. I got around 23.5 in mixed driving. This is just under what I was getting when tuned. I am going to look again at the MOP settings, think a bit and likely back off some. Also, going to get the right dwell table loaded when I get the car back. So, maybe there was a reason for all of this.

Thanks for listening and suggesting.