kojakrx

Which gas do you use to fill up your RX: Regular, Plus or Premium?

Husker4the

Whatever's cheapest ... which around here due to subsidy is usually ethanol mid-octane (generally 89 octane).

HarrierAWD

The "corn" gas is cheaper, but the gas mileage sucks with it. I normally get 24-25 mpg on the highway, but I could only manage 20-21 in Kansas and Nebraska. So I fill up with regular. (Regular is actually more expensive than mid-grade in the corn states, but I get more miles per dollar.) From what I hear, ethanol has less energy content than gasoline.

NeverSatisfied

How's that?

I used to put in premium in my IS (when prices were decent), but for my RX it's all plus. Regular gas on Maui is $2.69, plus is $2.79, premium is $2.90

HarrierAWD

'cause the mid-grade contains more "corn", which is relatively cheaper than gasoline. Therefore, some stations in the corn states have the same or lower prices for mid-grade compared to regular. It's not worth the saving because the corn gas gives lower gas mileage.

Rx900

amen to that! unless they drop the prices to less than $1 a gallon, i'll think about going premium but since it's not required (only recommended), forget it. I used regular gas all the way with my RX300

parula

A salesman at a local dealer told me he personally spoke to an engineer at Lexus and was told that regular is what the RX was designed to use.

Husker4the

I don't get any less gas mileage using "corn" ... it's cheaper here b/c the gov't encourages its use to help out the local farming economy.

bizzy928

Yep, thats right. Its also stated in your owners manual.

parula

Yea and we are saving money at these prices - glad I don't have a Beemer - don't they require premium?

jaydunn

You may think you don't get fewer mpg. but the chemistry involved says you must. Ethanol has roughly half the energy per gallon that gasoline has. Therefore, if your fuel is 10% ethanol, your mpg. must be reduced by 5%.

CarsFreak

Is that true? That means the 3.3L was designed to run on regular? Than what's with the premium recommendation?

I'm trying to figure out the ugly milege I'm getting with the 3.3L. Maybe it's because I'm using regular.

HarrierAWD

That's good to know, unfortunately my RX300's computer says otherwise. I monitor it as I drive.

jaydunn

The owner's manual for my RX330 says to use 87 octane or higher-that means regular is just fine.

NeverSatisfied

I'd better go read my manual...