nhi

Got a 2017 IS200t in July. Love it! Sales guy said regular could be used, but would just burn quicker. I’ve filled it up with regular 4 times so far (I don’t drive a lot- work remotely), haven’t seen much of an issue. However, I’m reading that premium should be used or the engine will become damaged. I plan on using Premium from now on after I use the full tank I have. Would the engine have any damage yet, given I’ve used regular 4 times already?

Note- Please spare me the “You’re too cheap to buy premium?” question. I did regular because I was told it would be fine. Had they said to use premium, I would have done that instead.

Sybaritic

No, your engine will be fine. Don't sweat it. It has a knock sensor that could slow the timing if it detects engine knocking (which could be caused by low octane).

Especially on a turbocharged engine, I think premium is a good idea since they run hotter. A premium car like ours deserves premium fuel anyway. You'll likely notice better fuel economy too moving forward once you use 91.

Sango

iTrader: (10)

Your engine is fine. The manual saids use premium so give it what it is designed to use.

For emergencies, yes you can use the regular if that is only available, it will not hurt it. If you do it regularly or to the extreme, yes there could be some implications.

nhi

Whew! I was worried after reading about the potential engine damage. I wish the sales guy had just told me to use premium, but the fault is also on me because I didn’t really pay attention to the car manual either.

So, premium it is from now on. Thanks for the info!

premier3IS

You are correct, you should be using 91 premium. Your engine is fine, don't worry but moving forward stick with 91 for best performance and to prevent possible engine problems in the future.


Min Octane Requirements

Sango

iTrader: (10)

You can also look at the fuel cap as well. I believe it saids premium fuel required.

nhi

That would’ve been the simplest thing to do, right? Except I totally ignored it and filled with regular anyway. Huge fail. LOL.

Any risk to me putting premium in before all the regular gas is gone? Or should I burn it all until I get the gas light, then fill it up? Asking as I am taking a long trip next week and wanted to fill up beforehand, but not sure if I’ll be on empty at that point.

Magellan

Just what we need—another regular versus premium fuel thread. They come along every month, like the full moon.

premier3IS

You'll be fine. It won't be a issue.

Jyk

I live in NJ, where people fill up gas for you. Twice now the gas attendant filled up my is300 w regular 1/4 of the tank before I caught it and yelled @ him. Filled the rest w premium - had no issues. ymmv though.

Sango

iTrader: (10)

You can do either or. Probably use most fuel up and fill it back with premium if you can.

nhi

Magellan, I do what I can to keep things repetitive. Otherwise, you wouldn’t be able to complain!
Although there is a process called keep scrolling and move on. Maybe you should give that a try, because clearly the whining from you isn’t working. I hope more and more folks post about this topic. ☺️

Thanks to those who answered without sarcasm.

arentz07

No, this isn't about that. OP was just concerned they might have already messed up the engine.

FWIW the person at the dealer who said that it should be fine to use regular is just wrong. I would be upset with him/her if I were you.

nhi

I am upset, for sure. I had already bought the car so it wasn’t as if it would deter the sale by telling me to use premium.
I’ll definitely be contacting the dealership.