what caused my increased mpg?

[kevinkay]

I did a lot of work all at once and now getting better gas milage, not sure what caused it.

start from the beginning......I constantly got 19.5mpg until I got new tires, went from Micheline "energy" to Micheline "primacy" was told by Micheline they are better performance but will get less gas milage. For past year with new tires getting constantly 18.5 mpg.

Did some maintenance work all in a short period and now getting 20mpg

changed transfer case oil
front and rear differential oil
transmission oil/filter change, went from BMW lifetime to Dexron VI
reset Transmission Adaptation values
oil filter housing gasket
DISA O ring replacement (did it because OFG thread said 'good time to replace".
Slotted/drilled brake rotors and new pads

I do mostly highway driving and pretty routine so mpg is not a fluke.
Overall car feels more "peppy".
I am thinking it was reseting transmission adaptation values or I had an undetected vacuum leak at the DiSA valve?

[four.8is]

There's no such thing as resetting transmission adaptation values..it resets itself every time you start the car.
As for increased MPG,my guess is DISA valve or you just use your AC less since summer is over.

[upallnight]

Originally Posted by kevinkay

I did a lot of work all at once and now getting better gas milage, not sure what caused it.

start from the beginning......I constantly got 19.5mpg until I got new tires, went from Micheline "energy" to Micheline "primacy" was told by Micheline they are better performance but will get less gas milage. For past year with new tires getting constantly 18.5 mpg.

Did some maintenance work all in a short period and now getting 20mpg

changed transfer case oil
front and rear differential oil
transmission oil/filter change, went from BMW lifetime to Dexron VI
reset Transmission Adaptation values
oil filter housing gasket
DISA O ring replacement (did it because OFG thread said 'good time to replace".
Slotted/drilled brake rotors and new pads

I do mostly highway driving and pretty routine so mpg is not a fluke.
Overall car feels more "peppy".
I am thinking it was reseting transmission adaptation values or I had an undetected vacuum leak at the DiSA valve?

If I had to guess it probably your slotted/drilled brake rotors. There's less mass spinning so less energy is required to get the car up to speed.

But this just a WAG (Wild Ass Guess).

[TiAgX5]

How do you like the BrakeLabs rotors? What pads did you end up going with?

[kevinkay]

Originally Posted by TiAgX5

How do you like the BrakeLabs rotors? What pads did you end up going with?

My eyes are drawn to the new rotors every time I walk to the car - Copied all your ideas, except wire brushed the calipers with a drill and didnt take off the fluid line. Thanks for the "heads up" on the duplicolor caliper paint - did a nice job. I also painted the hat of the rotor to match. Wish I sprayed the outer shield black while I had the rear rotors off. Went with low dust Akebono pads. Still in break in period but performance is great. Got to get new hub caps now.

Originally Posted by four.8is

no such thing as resetting transmission adaptation values..it resets itself every time you start the car.
As for increased MPG,my guess is DISA valve or you just use your AC less since summer is over.

Forgot about A/C - good point. I thought resetting adaptation values with INPA tells the car to re-learn your driving habits?

[TiAgX5]

Looks good.

[Qsilver7]

Originally Posted by four.8is

There's no such thing as resetting transmission adaptation values..it resets itself every time you start the car. ...

Just for clarification...because the "evolving" technology in BMW's developmental history of adaptive transmission control (ATC) which was first introduced back in 1994 on the e34 5 series is sort of complicated and varied...and can cause some confusion due to its complex engineering and design elements.

You are correct in that some AGS (adaptive) tranny operating principles...specifically in reference to the driver's influenced adaptations...can't be reset because the information is never stored in the TCM (tranny control module) and the transmission shifting pattern starts anew at each restart.

For example, the car will react to a grandma's light throttle manipulation & cause the transmission to have quick shifts from 1st to 2nd gear as it interprets her "granny-toe" throttle manipulations and engages the extreme economy transmission shifting mode. Whereas a driver with a slightly more average throttle manipulation may engage the economy mode transmission shift pattern or a more aggressive driver that presses the accelerator pedal quicker and further will probably engage the adaptive sport mode (not the same as the manually selected sport mode) where the shifts are slightly elongated to take better advantage of the engine's reserve power.

All of the last 3 examples mentioned in the paragraph above are not resettable (because the data is never stored)...thus if either of these types of drivers were behind the wheel for any length of time and then another driver with a different driving style got behind the wheel...the AGS part of the transmission would evaluate and select one of the 3 shift modes (extreme economy/economy/adaptive sport) based on that driver within the first few seconds of driving.

Where it can get confusing is...the mechanical side of the transmission CAN be reset...and this reset is based more on the transmission's adaption to long term wear...but this reset is accomplished with the use of connecting to the car's BUS system though BMW DIS/MoDic/GT-1...or if you have one of the aftermarket software/hardware set-ups that lets you delve into & communicate with the TCM.

Take note of the text highlighted in blue for the tranny adaptations that CAN be reset...vs the text highlighted in yellow which CAN NOT be reset:

I hope this helps clear up any confusion.

[kevinkay]

Thanks!
but to be honest, kinda makes it more confusing......sounds like I should have NOT re-set it after only changing fluid and filter?

[Qsilver7]

Originally Posted by kevinkay

Thanks!
but to be honest, kinda makes it more confusing......sounds like I should have NOT re-set it after only changing fluid and filter?

I wouldn't worry about it...with 160k miles on your tranny...and only this one reset...the adjustment (as you mention) may be noticeable now...but as mentioned in the text...the TCM evaluates the time change in gear ratio...and will begin to automatically adjust the transmission shift pressures to stay within spec.

Again, this one time reset won't probably be an issue...but I would recommend to not keep doing it repeatedly...as some could feel the need to "do it" annually (per se)...but just allow the tranny to compensate for any wear in the pressure clutches as it was designed to do.

The above comments is only my opinion which isn't based on ever having reset my transmission. But since you have the software/hardware...you can decide to do multiple resets (after all, its your car and up to you how you prefer to maintain it)...please keep the forum apprised of the pros/cons of multiple tranny resets despite BMWs recommendation. Hey, weren't they (BMW) the one's that originally said NOT to change the tranny fluid because it was supposed to be "lifetime" fluid?

[TiAgX5]

I did 3 trans drain refills (new filter with 3rd refill), found my trans was flairing shifts (slower/longer engagement). Did a trans reset and shifts were firmer/shorter.