Fuel Efficiency Decrease Following Vehicle Repair from Back-End Collision

Hi Everyone,

About three months ago, I bought a new 2014 Santa Fe Sport with the Technology Package. At that time, I was so surprised and excited that I was getting 28 mpg average. Three weeks after purchasing the car, I was rear-ended on the interstate. The frame was damaged and the bumper, back panel, and door had to be replaced. Also, when I first went to pickup the vehicle, the alignment was way out along with the steering wheel. I had to take it back to the repair shop to be aligned, and they said they calibrated the steering wheel.

Since the final repairs, my vehicle has had an average fuel efficiency of 24 mpg. Three questions - what could be causing this, how can it be repaired, and if it cannot be repaired - can I recover my losses from this?

It sounds like something is adding drag to the rolling of the car down the road, but with only average mileage to go on it’s impossible to guess what. It could be powertrain damage, wheel bearing damage, an alignment problem, a brake problem, or something else.

One thing you can do yourself is jack up each wheel one at a time with the tranny in neutral and the wheels fully chocked and try spinning each wheel by hand. If one wheel seems noticeably harder to spin, that might provide a clue. If that happens you could have them look at that wheel and its brakes. Other than that or an evaluation by a competent independent chassis shop, I can’t think of any other ideas. If I do I’ll post again.

Your car is still out of alignment. If that “calibration” of the steering wheel was to adjust the front tie rods until the wheel is straight, you are likely “crabbing” down the road. In alignment terms, you have significant thrust angle.

So either take it back again to the shop that fixed it and tell them to do it right, or find a good alignment shop that can fix it properly. I would be concerned at this point that the frame shop did not fix the car correctly and now they can’t align it properly so find a good alignment shop in your area and have it checked.

Simple brake test: After at least a 10 minute drive, feel all 4 wheels. A hot one means it’s dragging. BTW, I don’t believe you ever averaged 28 mpg with this vehicle.

The MPG likely got reset during repairs and you are getting your current average.

When the repairs where being performed the battery was probably disconnected.

When a battery is disconnected the Keep-Alive memory is lost to the computer. This means the operating parameters in the computer were lost and the computer has to relearn it’s operating parameters again.

Driving the vehicle for a while under different conditions allows the computer to relearn it’s operating parameters.

So drive the vehicle and see if the fuel mileage returns to where it was before the accident.


I will just address the alignment part. If the steering wheel was off-center there’s definitely an alignment problem and that problem is because something in the suspension and/or steering has been bent in the collision.

“Calibrating the steering wheel” sounds like hokum for adjusting the tie rods to center the wheel or removal of the wheel and rotate it on the splines to center it. Neither one is the correct answer to the problem.


This vehicle has drive-by-wire steering. And when doing an alignment on a vehicle with drive-by-wire steering the final procedure is to calibrate SAS, (Steering Angle Sensor) in the steering column.


Three montha ago it was warmer, that alone could account for the difference.

I understand the part about drive by wire but still think something is whacked. The OP said the frame was damaged which I assume to be in the rear and that can affect the front.

This might be even more worrisome if the repair costs were in the 5 grand or better range.
The shop might be a little iffy also because they’re the ones who ran it out the door and handed it over to the customer in that condition.

The most frugal Santa Fe Sport was is only rated for 20 MPG City and 27 MPG highway.

The vehicle is also unibody, it doesn’t have a separate frame.

24 MPG is exactly what this vehicle should be getting. There’s no losses on that front to recover.

I’d make sure your brakes are not sticking, but that’s about all you can do.