My wife filled our 2003 GS430 with low octane gas. Would it be OK to put a can of octane booster in with the cheap gas to boost the octane.
Best Regards,
Bob

 

Your car should be OK as long as she doesn't do it regularly. Just remind her to fill the tank with premium the next time or she gets to 1/2 tank this time. Cheer

 

Don't even have to put octane booster in; ECU monitors knock sensors and adjusts timing accordingly, essentially instantly. Unless you drive WOT, you aren't (usually) running into load conditions that require all the octane that we normally put in our cars.

Net result: you'll be slightly down on power in full throttle situations, maybe slightly worse gas mileage for this tank. No damage, though.

 

Here in Mexico City, people use Bardahl Octane Booster all the time. I would not dare touch the stuff. However, the supposedly 93 octane here is actually 91, so people boost it up.

If you want to do the car a favor, fill it up with Chevron since it has Techron.

I too have put in 87 octane here, horrendous Pemex gas, when Premium was not available in the middle of nowhere. No harm once I got across the border, I just put in some Techron and it fixed the problem.