icetime

I don't know how you guys are getting these mileage numbers. The DIC shows a 50-mile best of 28 (not sure how true that is) but my 'city' numbers are around 11s and highway closer to 20 (s. Cal to Vegas) @ 70 mph. I do live in a 'hilly' area. I have a 7-8% grade for 3/4 of a mile just to leave my neighborhood. But even with the hills, I am driving some other flat too, in city. I'm accelerating smoothly and am trying to get better mileage numbers, so I am not lead-footing (not babying it either as I want to train the tranny by my normal driving patterns). Am I doomed here? Is anyone else experiencing these kinds of numbers? Is a 'California' Sierra different than the other states models? 5.3 with 3.08 axle.

Thanks everyone. I will wait and see how the tranny learning mode goes based on your comments here. Good to have the support system here.

Good to know GM is monitoring for issues here. If I run into some enduring issue, it's good to know that someone from GM is 'listening'. Thanks again for the welcome.

It could be something to do with the trans 'learning' mode, as suggested (I hope), but definitely not the tires breaking loose. Has more to do with the uphill grade, than just pure acceleration, it seems. Not sure why it would be the 2nd-3rd gear shift only, and not any others. I guess this is one I'll pose to the dealer on the next service interval. Thanks for the welcome guys (appreciate the comments)!

I am new to the board, have a 2014 Sierra SLT with just 1k miles. Have been driving very conservative while breaking things in, for the most part. Today though, I was driving uphill and decided to put some foot into it, and noticed that coming out of 2nd gear, the shift to 3rd felt like the tranny was slipping before engaging in 3rd (at least that's how I can describe it, even though its automatic). I tried it two other times today (again, on the uphill, say 5-6% grade) and it is repeatable. I think this is occurring about 30mph or so (I'd have to confirm). On lesser grades or the flat, I don't experience this. I have a 3.08 axle ratio. Is this a defect? Has anyone else seen this? Any insight appreciated.