For 2 days I have been forced to fill my Lexus LS '99 with 87 Octane- Is okay? Today, added octane Booster??

If l were you, I'd just keep putting 87 octane in it. It is definitely not going to hurt it. It is cheaper than the premium stuff.

l really think that the octane boosters are a wast of money.they do help a little, but not enough to make that big of a difference. l would just stick with what your putting in, or jump up to the premium.which you should probably be putting in the car anyways. The higher end autos should be using a better fuel.

Chris

Octane booster brings up octane by .1 points per tank of gas.

Keep adding if you want to go that route.

Two days should not harm ur engine. You will get mixed feedback regarding octane rating & ur ''Premium Only'' Lexus. Most Lexus shops would tell u that u need to use premium because ur car is designed to run on it. You might think u r getting away cheaply, but it is really worth anything happening to ur LS? Also, u certainly do not want to give the manufacturer any reason to void ur warranty. Highly unlikely, by why risk that over small savings.

l hope this helps.

Generally speaking, most vehicles that run on premium can handle reg unleaded in a pinch. The engine computer will adjust for the fuel. Your fuel mileage will likely decrease, though.

Higher octane just means ur vehicle will not ''knock'' through the RPM range. It does not mean you're getting anything better than regular if the engine performs fine.

Did ur engine knock, bump, hesitate etc. during these two days? If not, then it is not doing ''harm'' to ur engine. What it might do it reduce ur fuel mileage somewhat because although it does not knock, u could lose some performance because some manufacturers base their HP rating on running on premium, so u usuing regular u might get some performance loss. With that said, this hold more true for performance engines & sports vehicles, than the LS l would imagine.

Anyway, if u want, play it mid level & get the mid-grade fuel. No need to baby ur car anymore if it does not need to, because it is just waste.

l guess you're in an area that still has gas shortages from the recent hurricanes. l hope that ends soon.

l put mid-grade in my Mini most of the time, & have not noticed any problems. The computer controls the fuel mixture in ur engine, so it probably wo not cause u any trouble. Those octane boosters r really just a waste of money.

The biggest problem u will probably have is with using fuel mixed with ethanol. Ethanol provides less energy per gallon, so ur gas mileage will decrease, & u will end up having to fill up more often, thus ultimately using more gasoline.

l probably would not add octane boosters if l were you--my 03 GS manual specifically warns the user against using octane boosters, specifically those containing MMT.