When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Hello all. Did not really think I would have to come to a forum to help find answers about my car but here I am I suppose. I have a 2018 Civic LX with the NA 2.0 and a 6 speed manual transmission and over the past few months I've been noticing my gas mileage get worse and worse. When I first got the car I would get around 28-30mpg in the city and now I'm sitting around 21-22mpg. At first I thought it was nothing but there's no way there's nothing wrong with it. I haven't done much to the car at all, new battery, new air filter, and new tires. I also noted that while I'm taking off from a stop the little MPG gauge pretty much drops to 0 no matter how I drive it. My car has 65k miles on it. Any help or advice would be greatly appreciated!
did you notice it when temps started to drop? Lower air temps have a 2-fold affect on cars.
1) tire pressures tend to lower if you don't keep pressures up, giving more rolling resistance and thus, lowering fuel economy (you also tend to feel a bit more power as a byproduct)
2) denser air entering intake stream and the ECU putting more fuel in
I mean, it shouldn't have that drastic an effect on fuel economy like you're seeing, but it definitely contributes. I recently ran into the same issue with my '18 sport hatch 1.5T CVT. Got new tires (which were stickier than OEM), and temps started to drop. I took a road trip to Salt Lake City from Vegas (and back down to Vegas), and, when I used to average 36-42mpg on road trips, it dropped to 28-32. Now I'm sitting at like 28-30 with 90% city streets which is still low for my liking, but I'm content with it.
