[Iamantman]

Super short trips like that are murder on gas efficiency. I'd bet that's your #1 culprit like Maven and blackburn have said. You've checked obvious things like making sure your tire pressure is good right?

To test, I'd take it out on the highway and drive 20 or 30 min. If you're not getting 30-40 mpg there then you might need to take it to the dealer to check it out. If you're not throwing any codes though they're gonna send you on your way most likely and tell you what we're telling you here.

I find my sweet spot for gas mileage on the highway is around 65-70 mph. I can approach 50 mpg there. If I'm up in the 70-80mph range I'm usually in the low to mid 30s.

 

[Iamantman]

Yeah I mean these are small, lightweight cars with very efficient direct injection engines. If you're averaging in the 20s for mpgs there is either something wrong w the car, or you're driving too aggressively. Not much of a grey area there honestly.

 

[Iamantman]

I believe Redline, Premier RS, and maybe Hatch RS come with 18s.
The LT sedans, at least 2016-2017, came with 16s, Goodyears on most, Hankooks on RS, except my fleet ordered 2017 RS has Goodyears.

My 2018 Hatch RS was an LT model and came w 16s. I plan to upgrade but will probably only do 17s because I'm terrified of driving it around the city with 18s. Philly potholes are real man... haha

 

[Iamantman]

Ride quality sucks on the 18's. I went up a sidewall size when I replaced my tires and it helped a bit, but the 17"s are probably an even better choice.

Haha yeah I figured. I think it's just something people get used to. Personally that takes a toll physically on me and the car so I'd rather not risk it. Plus like you said below, it adds even more the mpg game.

That said I think if I lived in the suburbs or down south with pretty open flat roads, I'd definitely go oversize like that. It just looks so gooood.