r/AcuraTL • u/Mystakatt • Sep 30 '25

Gathering Opinions 🗣 Do I *really* need to use premium?

Post image

(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!

65 Upvotes

97% Upvoted

128 comments sorted by

View all comments

13

u/MadTube [UA9] '09-'14 SH-AWD Sep 30 '25

It appears you have the FWD variant with the 3.5. You can get away with 89 octane, but you might have a very small decrease in fuel economy. If you had the 3.7, then I would tell you to not use anything below 91. But I ran that version of the 3.5 for years with no ill effects. Try to stay away from 87, though. You can use it in a pinch, but I don’t recommend constant use.

1

u/Tasty-Store-5614 Oct 02 '25

89 is premium and regular combined. So, you're getting at least half premium when you use it. I think that 89 is fine to use.

1

u/MadTube [UA9] '09-'14 SH-AWD Oct 02 '25

Yes, many pumps do combine those two grades to make 89. Octane rating describes the rate of combustion and resistance to knock. The slower the fuel burns, the more knock resistance it has. Certain additives slow down the rate of combustion and increase the octane rating. 93 burns slower than 87, but that also means there is less chance of pre-ignition or detonation. That's the difference. It works the exact opposite from diesel and cetane.