Learning transmission and new tires.

[TheyCallMeTaco]

Put about 2.5k on original tires before having 235x85x16 installed Tuesday. Drove 2.5 hrs on mostly Interstate at around 78/9 mph to get to my hunting area today. It was windy and hilly. That said the truck spent most of its time in 4th and 5th gear. 5th I understand, but it spent most of its time in 4th. Needless to say mpg was terrible. I understand the tires are taller and heavier than original, but not by that much. Is it possible it's going to take time for the transmission to relearn the new tires? Thanks

 

[Biohazard]

Put about 2.5k on original tires before having 235x85x16 installed Tuesday. Drove 2.5 hrs on mostly Interstate at around 78/9 mph to get to my hunting area today. It was windy and hilly. That said the truck spent most of its time in 4th and 5th gear. 5th I understand, but it spent most of its time in 4th. Needless to say mpg was terrible. I understand the tires are taller and heavier than original, but not by that much. Is it possible it's going to take time for the transmission to relearn the new tires? Thanks

It'll attempt to learn, but won't do very well. Try shifting into "manual," and put it in 5th gear, that'll adjust the programming a bit. I had some success with that.

Second, get a tune. I'm using KDmax, but there are lots of options and all are better than the stock engine-tiramisu on tuning.

 

[TheyCallMeTaco]

Thanks for the response. A tune is in the very near future.

 

[Biohazard]

Lol, tiramisu sounds good. But that was supposed to say engine-transmission

 

[Meclizine]

I think resetting the learned values or whatever it's called is SOP when getting a tune. I have the same tire size and all I have is a tune.

 

[jeepnik]

Silly question, but is the ECT turned on?

 

[TheyCallMeTaco]

Silly question, but is the ECT turned on?

No. Got it tuned today and it's a different truck. All is good.