LTZ Turbo - Poor Gas Mileage

[nkaufman]

Hello,

Recently got a 2015 Sonic LTZ Turbo for my wife.

She's been complaining that she's filling up gas like crazy, car seems to be giving extremely poor mileage.

Car is CPO - Certified Pre-Owned and we have 12K/12mo warranty.

I'd like it to take it to the dealer and was wondering what should I ask them to look at.

Thanks for your assistance.

 

[Maddmatts]

Check to see what the trip computer is showing for fuel economy. Note that this only shows the average since it was last reset. If it has never been reset, do so. This way you'll get a more recent average over the next few drives.

You can also use the trip odometer and some easy math between fillups to determine actual fuel economy. MPG = mileage since last fillup / gallons needed to fill tank.

 

[Blue Moon Sonic]

I would also make sure shes just not mashing the gas like an NA vehicle to get places. Anything turbo requires different throttle control habits. There is also winter blend gas also making things pretty dismal. How many miles are on the vehicle?

 

[JTee2017]

Hello,

Recently got a 2015 Sonic LTZ Turbo for my wife.

She's been complaining that she's filling up gas like crazy, car seems to be giving extremely poor mileage.

Wow. . that is bad.. .

 

[Natesriv]

she needs to reset the trip odometer and then figure her mileage over 2 or 3 fill ups...
lead feet will result in lower mpgs!

 

[66roadie]

I would also make sure shes just not mashing the gas like an NA vehicle to get places. Anything turbo requires different throttle control habits.

True.. that turbo is a real gas hog, If your car is quiet, you need a boost/vacuum gauge to help keep it out of boost and get decent gas mileage.

 

[Blue Moon Sonic]

The fact these cars don't have a boost gauge from factory is really pretty ****ty. It's a pretty important tool for a FI vehicle.

 

[MaD]

I avarage about 25 mpg here in Seattle area, but when I was in AZ it jumped almost 10mpg... as for gas, winter blend can knock it down, as for driving, I drive mine like I stole it and still get 25 mpg min...

Sent from my SM-G900T using Tapatalk

 

[66roadie]

I avarage about 25 mpg here in Seattle area, but when I was in AZ it jumped almost 10mpg... as for gas, winter blend can knock it down, as for driving, I drive mine like I stole it and still get 25 mpg min...

If you actually drove it like you stole it, you'd get pretty good mileage.

 

[bluejay]

I drive it like I stole it and I’m getting pretty good mileage. But I have the rs manual. I can’t speak for the auto’s , but I would assume they are worse. I have noticed the mileage getting worse since the winter blend gas . Maybe that’s part of the problem.

 

[Blue Moon Sonic]

Mine is an auto with the RS final drive(transmission swapped). It's modded and I drive mine like I stole it regularly. Currently averaging around 30MPG on winter blend.

 

[MaD]

Out here in WA we have these things called mountains... and any car out here will get lower mpg because of that. That's why I said when I was in AZ I got a lot better mpgs. [emoji41]

Sent from my SM-G900T using Tapatalk

 

[gnonne]

I own 3 Sonics. Two 1.8 and one 1.4 Turbo, all with the same 6 spd automatic trans. The mpg is the BEST on the 1.4 turbo sedan, 39-40 highway, next 1.8 sedan, 35-36 hwy, dead last, 1.8 hatch, 31-32 hwy. We drive them all pretty conservatively in town and at 73 mph on hwy with cruise.

Driving slower (like 63 mph on a two lane rural) makes them all go UP by at least 4-5 mpg. Air resistance is the mpg killer at high speeds, especially on the hatch.

 

[JTee2017]

I own 3 Sonics. Two 1.8 and one 1.4 Turbo, all with the same 6 spd automatic trans. The mpg is the BEST on the 1.4 turbo sedan, 39-40 highway, next 1.8 sedan, 35-36 hwy, dead last, 1.8 hatch, 31-32 hwy. We drive them all pretty conservatively in town and at 73 mph on hwy with cruise.

Driving slower (like 63 mph on a two lane rural) makes them all go UP by at least 4-5 mpg. Air resistance is the mpg killer at high speeds, especially on the hatch.

I have a 2017 Sonic HB and experience about the same for MPG. In mixed city(15%), semi rural (50%), and some state highway (35%) driving, we are getting about 30.3 MPG. The best so far was a couple 150 mile round trips to the city on state roads going 55 to 60 MPG. This included a dozen or so stop/traffic lights.
The worst so far was 28 MPG which was mainly city and cold starts what with temps in the 25F to 30F winter weather.

Wondering, if on the HB some aero type spoilers along the rear spoiler would help?

 

[nkaufman]

Check to see what the trip computer is showing for fuel economy. Note that this only shows the average since it was last reset. If it has never been reset, do so. This way you'll get a more recent average over the next few drives.

You can also use the trip odometer and some easy math between fillups to determine actual fuel economy. MPG = mileage since last fillup / gallons needed to fill tank.

Thanks, had no idea about that feature.

Checked the manual and have set it. Let's see what the results are.

Plus I filled up the gas this time and noted odometer reading and noting miles every couple of days (since DW refuses to do so )

 

[nkaufman]

I would also make sure shes just not mashing the gas like an NA vehicle to get places. Anything turbo requires different throttle control habits. There is also winter blend gas also making things pretty dismal. How many miles are on the vehicle?

About 45700 miles, not much

 

[nkaufman]

Car is mostly driven in city, rarely on highways.

Perhaps that could also account for low mileage, though the Yaris gave much better mileage in comparison (not Turbo of course)

 

[nkaufman]

Have some metrics.

MPG shows approx 28 mpg.
Miles driven 129 miles

But fuel indicator has gone down from Full tank to below half (one less indicator than half).

This does not make sense.

MPG and Miles driven suggests 4.6L of gas used. Where is the rest?

Could the mpg not taking a/c, heat, lights etc.? i.e. similar to how car manufacturers calculate mpg

 

[nkaufman]

Someone mentioned lead foot etc.

But it is the same driver that drove a Yaris and now a Sonic and for one car to be giving a much higher mileage was just surprising.

Yaris gave a much higher mileage and that is what caused us to look into this issue.

 

[Ponchoguy]

I use the EPA guide on the sticker as a baseline. If I'm getting that for city/highway, I figure I'm in the ballpark (generally) of what the car should get. For the most part, I get the 25 mpg in the city and 35 mpg on the highway like my 2012 1.8L sedan was rated for.

I usually do better on the 50+ mile run each way up and back to my sister's in NJ to visit as it's all straight highway driving on Route 78 (for those that are familiar with this neck of the woods). Through the boroughs of NYC during the week, I usually get 23/28 depending. Overall, not too bad. I try to keep my tire pressure maintained and go with the flow of traffic.