phenom78

well my momma borrowed my car, and decided to be nice so she filled it up for me, i always fill it up with 91 premium (CA) but she filled it up wit 89, which is the middle one, super unleaded i believe, will i notice anything different, and will it mess wit the engine n what not.. thanks for yo time.. adios

Blk03S

Don't sweat, the engine will be fine. Any loss in performance will be negligible. Once you run the tank down a bit, put some more 91 in it, if it makes you feel better.

-Jon

phenom78

all right, great... thanks man for the quick post

gavriil

No issues with engine damage. Just performance losses at higher rpm, especially during hot weather. That's all.

And the performance loss is happening from the ECU which is doing that to protect you from pinging issues.

goldmember

Isn't octane rating a linear value?

Is a 4.5% higher octane rating worth an extra 20 cents a gallon to you guys?

Performance and practicality are completely different.

pimpscls

my dad used to fill it up with 89 thats not bad is it?

BEETROOT

if you want to be practical go buy a kia or a hybrid. its like 2 bucks a tank difference.

goldmember

You're right, Beetroot, but I'm talking in terms of real difference vs. what the car + oil companies would love to have you believe.

I had this discussion with a friend lately, who doesn't know much about cars at all (just like me =) and in any case, he was telling me about the mileage advantage of putting 91 into your car, but his facts were fuzzy (even he didn't remember).

So I'm here asking questions, not stating shit. Neither of my two questions were answered. I'd appreciate if someone with a good amount of automotive knowledge would inform me.

SpeedyV6

The CPU will automatically retard the ignition if it detects detonation. The engine may run slightly hotter under those circumstances but unless you're leadfooting it there shouldn't be a detectable difference. The '04 Accord 3.0 L has similar compression but takes 87 octane. Fuel mileage s/b unaffected.

BEETROOT

goldmember...didn't mean to sound like an asshole before, sorry if it came out that way.

I filled up on 87 for two weeks during our little gas crisis out here in the desert, I couldn't tell any difference

thealliance15

i was fillin 87 the whole time i have had the CL (5k Km) till about a month ago, when i started putting 91, the first time i did the car burnt the gas so fast and i wasn't even givin her that often. but no i can feel an imporvment in top end a little better gas miliage, point is lesser quality gas is ok if u don't drive hard.