My 1.4t in the Cruze, same as the sonic engine took 5w30. Speaking of which how do you feel on 30 vs a 40 weight in the 1.4T? Did you just switch with "higher" mileage or do you think no matter what, its a better choice for a 1.4t? My dad has a 13 Cruze Eco auto with 60k or so and he asked me about maybe switching to a 0w40 due to the turbo/heat. I was telling him how reading on here over the years from UOAs that the 1.4t absolutely shreds/cooks oil. I think most synthetics were done at 7500, which is why he asked if a 0w40 would be better.
Anyway, the 1.4 NA calls for 0w20 instead of a 5w30 that the 1.4t does which also makes me wonder how different they are or why, other than just a play for extra MPG.
Also...Are you referring to an AT or a CVT? The Spark has the CVT, which I've read is super important to get changed at 45k or so, then you wont have issues. I did that and am going to maybe have them use Amsoil CVT fluid. My dad's Cruze is probably due for an ATF change, are you referring to the standard auto that I'm assuming is the same between the Cruze and Sonic, or the CVT in the Spark?