Yeh I bought the 1.8 with manual gearbox.Goes really well for engine size vs weight of vehicle.I attribute to the gearbox.Just couldn't trust the auto..or the turbo from Chev(Holden here in Aust).Maybe try a tune shop for solution if you think it is really worth it.
Our 2018 Trax LT is very definitely underpowered when compared to my last Chevy. That old blue beauty was a 325HP 1969 Chevy Camaro with the 396 engine's output tweaked to at least 360 HP wth some surgery that I did with it.
While the Trax is no hot rod, my wife is happier with it than the 2005 Pontiac Vibe (Toyota Matrix in disguise) which the Trax replaces.
I kind of thought for an 81cid engine, it runs pretty good. Will squeal the tires from a take off and will run up to 90 + on the highway if you're not paying attention (**** we needed to get a model with cruise). Saying that, I wished the 158hp engine was available in the Trax like it was in the Buick.
I have a Diablo tuner for my truck. It made a noticeable difference of an increase in BOTH power available AND MPG. Any time you can get more power and better gas mileage it is a no brainer. They do have tunes available for the Trax 1.4. If our Trax was not a lease I would have probably already tried it. I still might.
The only issue is the takeoff from a dead stop with the engine at idle. It takes a bit for the turbo to spool up to give it some acceleration. If you know you will need quick power like when you are waiting at a stop sign for a gap in traffic to squeeze thru, it helps a bit to hold the brake and give it a bit of gas to slightly increase the RPM and get the turbo to start spinning. The computer will not let you hurt the engine or trans by giving to much gas. But this will get you a bit quicker of a "launch" (If I can use that term with a Trax).