amf1932

Does the Owners Manual for the above car mention anything about using 87 octane fuel(Regular grade)? I know that other model Lexus's say that you can use regular with slightly reduced performance. I was wondering whether this holds true for the GS's also. Thank you.

LS4fun

I do not believe you can use regular.....i have always used premium and I think that is what is required.

rominl

iTrader: (4)

you can most definitely use 87. i think the computer will just retard the timing for the lower grade gas. you will lose some power and probably get some pinging as well. but the car will still run

granted though, i don't see any reason why you want to use 87. it's not like 91 is a lot more expensive

kissbang

Yeah, it says use 91... but gas rated as low as 87 MAY be used if 91 is not available.

Bigmojo

Try this experiment:

Use 91 for 2 tanks. Drive normal and figure out the average MPG.
Use 87 for 2 tanks. Drive normal and figure out the average MPG.

Now, If you take the MPG from using the 87 and compare it to the MPG when using 91, you should find (as I did, as well as a few others) that there is marked difference. Take the MPG and divide by the cost per gallon to figure the cost per mile. You will find that cost per mile of 87 oct offsets the increased cost per gallon of 91 oct.

Bottom line. Use 91. I am going to make the assumption that you are asking just for the sake of knowing..But if not...If can afford the car but not the gas you got BIG problems.