Just drove my new BRZ home... on the wrong octane.
 

So I just drove my new BRZ off the lot. The salesman filled it up with a tank of gas (it was only at 1/4 tank.) I know for a fact that he put 89 octane in it. I then drove it 90 minutes home. I'm now reading the owner's manual and it says never to use less than 91, and there are lots of posts on the forums about how 89 will cause damage.

This is a brand new car (had less than 10 miles on it.) Is 89 octane "safe" in the sense that you just don't want to do it long term, but that the car will just adjust timing and run poorly until I use up this tank, or are there larger forces at play here and should I be doing something else...? Will it cause even MORE problems due to the fact that I'm breaking the engine in with the wrong octane? I'm really hoping it's one of those things that's really not a big deal and that I shouldn't worry about causing damage.

From my prior experiences and past vehicles, I've also found out that many dealers put less than what's recommended, and that's why I've specifically written on paper of 'no fuel up' for my ordered BRZ. It doesn't make much of a difference however I'm just very OCD.

You should be just fine, I'm sure. As others would mention, go ahead and follow the break-in process and burn the fuel as you normally would so that you can focus on your next fuel up with the correct octane.

No worries, partner. :)

Yes, no worries at all.

You'll be fine. Just get some 91 in there asap :)

Oh no! That's all bad!!!

ITS TOTALED

My dealer did the same and then argued with me when I said minimum 91. They thought that 91 was only recommended. Showed them the manual and they were rather embarrassed.
Not a huge problem as the ECM will adjust for it for the short time the tank will last.

And then you posted, in the WRONG FORUM... No BRZ's allowed in here :paddle: lol just pulling your leg.

But really you'll be fine! You were (hopefully) driving her easy as she is new. The car is factory tuned for 91, and that's how it will perform best, and make it's best power figures. On 89 you'll see poor power and poor fuel economy. Just fill up with premium min 91 and you'll be fine.

post like this should be automatically deleted.

it'll be fine, go out and enjoy your new brz!!

Thanks guys. Yeah I realized this was in the wrong forum when I couldn't find it after I posted, lol. I'm definitely following the recommended break-in procedure (under 4k, no heavy throttle) so I haven't ragged on it at all. I kind of figured it was probably okay. I texted the sames guy and he said he asked their mechanic and the mechanic said 89 is fine, lol.

There's a knock detection sensor that will make the ECU pull timing until you refuel with 91 or better. Most likely as previously stated, mileage and power will be marginally reduced but absolutely no harm will be done. The person who fueled up is a moron. And sadly it could have been the sales rep. They sometimes know the least as this doesn't deter their overall ability to close deals.

As soon as there is any room in the tank start putting in the highest octane available. They'll average out.

I'm going to wait till it gets to half and then put 93 in it. That should bring it to 91! :P

And 93 from here on out!

You shouldn't be so salty and learn to take a joke.