2018 Chevy Equinox Gas Mileage

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70srocker

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I bought a used 2018 Chevy Equinox, LT, front wheel drive about nine months ago. I've averaged around 25.8 miles a gallon driving in town. The last month its dropped to 20.2, then 19.7 and now 17.8. I've had it in for service and the spark plugs were changed and they put something in the fuel line to clean it out. Nothing has helped, it's getting worse. They ran a diagnostic test and everything checks out fine. It is winter now, but the drop started before it got cold. Air in the tires is fine. At a loss and can't understand this. Vehicle just turned 54,000 miles.
 

ricklack

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I would hope they looked at the engine air filter and cleaned the throttle body. i would run it by an auto parts place that advertises free code scans and see if they find something.
 

70srocker

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I would hope they looked at the engine air filter and cleaned the throttle body. i would run it by an auto parts place that advertises free code scans and see if they find something.
I will do that. Thanks for the reply.
 

RIT333

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In the northeast, come winter, they switch to a winter grade of gasoline which has less BTU s and will decrease your gas mileage. Also, do you remote start your car ? That will decrease your gas mileage to zero during that time period.

But you are seeing a huge decrease in mpg. barrios says that changing your O2 sensors can improve gas mileage, but I have never tried that. He says that they get lazy, I believe.
 

PoManNox

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You can't go by the vehicle's information center readouts. The only number that matters IMO is your fuel economy average over an entire tank of fuel. Some trips might me 17mpg per the vehicle and some might be 29mpg in the winter months.

It's been awhile since I did a hand calculation for avg fuel economy, but with my driving with my 2021 LS AWD 1.5L, the vehicle tells me I get ~32mpg avg in the summer and 29mpg in the winter. I'm like 90% straight hyway use.
 

70srocker

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I found the issue. Yesterday I typed in Google, “can gas mileage go down after an oil change”. The answer was yes, if the wrong oil was used or too much was put in. I checked the dipstick and it was an inch over the full line. I took it back to the Chevy dealer who changed the oil and they figured out they thought I had a AWD. It takes almost a full quart more than a 2 wheel drive. They drained the oil and filled it back up. Now getting 25.8 mpg.
 

RIT333

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I would expect some type of financial compensation for an error like that. If you didn't catch it early, you could have done engine damage. I would try to get in writing what they did...just in case.
 

Autoworker 74

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I bought a used 2018 Chevy Equinox, LT, front wheel drive about nine months ago. I've averaged around 25.8 miles a gallon driving in town. The last month its dropped to 20.2, then 19.7 and now 17.8. I've had it in for service and the spark plugs were changed and they put something in the fuel line to clean it out. Nothing has helped, it's getting worse. They ran a diagnostic test and everything checks out fine. It is winter now, but the drop started before it got cold. Air in the tires is fine. At a loss and can't understand this. Vehicle just turned 54,000 miles.
Are you calculating your mileage yourself based on miles driven divided by gallons or are you relying on the number the car shows when you look it up. If it's the latter maybe it's the system that calculates it for you. My milage can change quite a bit if I go from all local stop and go to local stop and go plus a couple of side trips that put me on the road even for a couple of short trips.
My 2018 will give me 40 MPG with strictly highway driving and using the cruise control.
Try topping off and immediately hit the highway. Do steady speed for 25 miles and return to the pump to fill up. Then calculate your MPG. Seems like a lot of work but it shouldn't cost more than $5.00 depending on your price for gasoline.
 

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