I am having the same problems with poor gas mileage. My buck is a 2016. Must be just the way it is with this model. I have been to dealership they did a fuel injection cleaning and that did not help. Now they say we should look at spark plugs. Buick only has 30,000 miles on it.
Your vehicle is rated at up to 28 city and 34 highway , the key part is up to not guaranteed. What are you actually getting and what type driving do you do. I suspect you really don’t have a problem .
If you took a 100 mile trip at 65 MPH with proper tire inflation you might get over 30 MPG and might get 34.
Based on the mileage, I’d say you probably don’t do much highway driving. I get at least 20% better gas mileage going to work in the morning that returning home in the afternoon. The main difference is no traffic in the morning and heavy traffic going home. If you only do city type driving, the gas mileage may be a lot lower than you expect. What is your gas mileage and how do you measure it?
A faulty engine thermostat is a common cause of lower than expected mpg. Ask your shop to verify the engine is running at the correct coolant temperature.
To what are you referencing? Also what kind of fuel economy are you currently getting, and how are you arriving at that figure? What kind of fuel economy are you expecting?
Not surprising. It’s unlikely a newer vehicle would have clogged/dirty fuel injectors.
True. I had the original plugs replaced at 110K and didn’t notice an improvement. One possibility is low tire pressure. Have you checked your tires lately?
… as are the way that the OP drives his/her vehicle, and its typical driving patterns.
Unfortunately, none of us have any insight regarding those potential issues.