If you have poor gas mileage and no check engine light, you might not know what parts to inspect to find the cause. In this video and article, our mechanic Sue shows what suspension parts you’ll want to look at if you notice the fuel economy dropping in your car.
Suspension Parts That Can Cause Poor Gas Mileage and No Check Engine Light
Parts to check if you have a vehicle with poor gas mileage and no check engine light
- Check the Tires
The tire tread can tell you if you have a suspension problem contributing to poor fuel economy.
Turn the wheel all the way out and listen for any noises that could indicate a problem, like squeaking. Look at the outer edge of the tire, and the inner and center tread.
In this example we have wear on the outer edge. A bad outer tie rod end can cause the wheel to wobble enough to wear the tread but not cause more noticeable symptoms like a difference in how driving feels.
Run your fingers over the tire and look and feel for feathering and listen for a paper sound. Feathering is an indication the tire is not aligned properly.
More tips on inspecting a tire
- Check the Front and Rear Suspension Parts
You may have received an alignment recently but you can still run into problems with fuel economy if a part goes bad or you hit a big pothole.
Bad suspension parts can cause tire wear and that causes the car not to drive straight down road and will give you poor gas mileage. As you accelerate, the tires are fighting against the road, and this wears out the alignment of the wheels and the resistance wears on gas engines.
Bushings can wear and shift the differential if a car has them on the rear, and that makes resistance. For example, the car could have been in an accident and the rear end shifted but no one noticed. There could also be a problem with the bushings, like dry rotting, on parts like the control arm. If the bushings are worn, the part will need to be replaced.
Jack up car with a jack and jack stand. To test the tie rods, grab the tire from the 3 and 9 o’clock position and press in and out, feeling for play and listening for noise.
To test the wheel bearing, grab the tire from the 12 and 6 o’clock position and feel for play/looseness.
More tips on inspecting suspension parts
More How-to Videos and Tips
Check out our other articles and how-to videos. Find out what other parts can cause poor fuel mileage and find out how to fix the problem yourself with step-by-step instructions in our how-to videos.
- MAP vs. MAF vs. IAT Sensors
- Are Brake Pads Universal?
- How to Test the Fuel Pump Relay with a Multimeter or Test Light