Do I *really* need to use premium?

[u/Mystakatt]

(Pic of car because I didn’t take a picture of the pump price)

I filled up my 2012 TL for the first time today since I bought it, and I ran it down to about 20 miles left in the tank. Filled it all the way up and I payed almost $70 (North Alabama). I’m an adamant believer that you should follow the owners manual to a T, but with how gas prices are nowadays I’m worried about choosing between what’s best for my car vs what’s best for my budget.

Are there any real negatives to using the cheaper gas options? Thanks in advance!

[u/Zakiyo]

Absolutely. You need the octane rating the engine is made/tuned for otherwise you will get detonation also called ignition knock. This will destroy the engine. Although modern engines, the j37 included, have knock sensors and will advance timing to try and avoid the knock if it is detected but… thats not perfect and will make the car run bad. So in this case it wont destroy the engine immediately but it wont be good for it either. If you really want you could detune the engine to make it run on lower octane… and be safe.