Q: i put 91 super in my car and is says use 87 premium now my battery light is on. what is going on? 2009 Kia Sportage

asked by on

I put 20$ worth of super 91 fuel in my vehicle before i realized it was super. I had a quarter tank of regular 87 gas in it from before. This is what my car calls for. After i realized it i paid for the gas and started my car and now the battery light is on. The owners manual says using plus fuel can really mess up my car and transmission. What did i do to my car?

My car has 170000 miles.
My car has an automatic transmission.

Hello - you did nothing harmful. Your car may have a small level of performance improvement for this tank of fuel, but nothing extraordinary. Long term use of fuel with a higher octane level, MAY lead to increased levels of unburned additives in the exhaust and catalytic converter, but we’re talking about 10s of thousands of miles here for any "damage". The engine simply burns the premium fuel as-is, and doesn’t really use the additional anti-knock additives in the fuel. No harm, no foul. The battery light may be a slipping or broken serpentine belt, a failing alternator, or voltage regulator. I recommend a charging system inspection performed by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, diagnose this problem, and give you an accurate assessment of damage and cost estimate for repairs.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. i put 91 super in my car and is says use 87 premium now my battery light is on. what is going on? 2009 Kia Sportage

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Radio makes a static noise after making a right turn

Are you having a problem with a noise coming through the speakers of your audio system? It is possible some of the audio components got wet before the window seal was replaced. You should have a speaker amplifier mounted inside...

Q: Check engine light on and the P0128 code is showing

The P0128 code is most likely caused by one of the following three issues: a faulty thermostat, a faulty engine coolant temperature sensor, or a processing error in the ECM. The coolant temperature needs to measured using a temperature gun...

Q: Ran out gas and put gas back in but car still won't start

Hello. When the vehicle is completely drained of gas, the pump and related fuel system components can be stressed to the point of failure. This will cause the vehicle to not start Start by checking the easy components like the...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.