rikkus256

2011 ES 350 now officially recommends 87-octane and drops horsepower to 268 with the SAME EPA Fuel Ratings 19/27
I guess that ends the debate

If you want that extra 4HP (which I doubt anyone can feel the difference), go for 91+ octane, otherwise just use 87 and save some cash. To a lot of us it's not about saving money but about not wasting money on something that we don't need

vetkilr

89 octane...here for me. I know it can run 87, but like alot of people do, I run higher octane for piece of mind. Its no different then some do, when they run synthetic oil, the car doesnt need it, but it is extra protection/insurance for an extreme condition that might come up.

2008ES

Here's my take on the octane question. I haven't read all 21 pages of this thread, so I may be echoing other posts. My perspective comes from driving a 6-cylinder Avalon daily for more than 15 years, averaging 29K miles per year, and keeping track of mileage for long stretches -- months or years at a time. Between 1995 and 2008 my Toyota never saw a drop of gasoline that was not premium (91 or higher octane). In 2008 I switched to 87 octane and used that exclusively for the next 2 years until I traded for the Lexus. My average using premium -- and again this was over long stretches of time, not just a tank or two -- was consistently between 28 and 29 MPG. My average using regular unleaded, driving those same roads at the same speeds (granted the engine was older but in excellent condition), was between 26 and 27. So you are looking at around a 7% difference between the two.

Now look at the cost of a gallon of gas. Right at the moment in my area of Georgia we're looking at $3.35 versus $3.65 between the two grades. This is about an 8% difference. You can see where I'm headed with this. Although it's not razor-sharp accurate, if you take the average annual miles driven of 29K and work the math, I used 1,094 gallons of unleaded per year versus 1,017 gallons of premium. Given the current prices, this would translate to $3,665 of unleaded versus $3,712 of premium. A savings of $47 per year. You have to decide for yourself whether the benefits of running premium in your Lexus are worth $4 per month.

I attribute the longevity of the Toyota partly to religious oil changes and lots of gentle highway miles, but also to the use of premium gasoline which was strongly recommended in the manual. As it stands right now, I haven't used anything but premium in my '08 even at the inflated prices. And I don't believe I'll start any time soon.

And of course, YMMV.

Richard95

It looks like you have done your homework.

Blueshark

I did a 6 months test on my ES350 08 and regular gas does less mileage than premium. I drive montly the same distance from one city to the next with cruise control and the premium average is 8.5 liters per 100km vs 10 liters per 100km with regular.

LexBob2

On a % basis that's a big difference.

OTOH, in the U.S., the EPA rates the '07-'10 models at 19/27 mpg (22 mpg overall) on premium gas, and the 2011 the same 19/27/22 on regular.

Go figure. As mentioned earlier the conversation goes on.

amf1932

My window sticker says 21 City 30 Highway. This is on a '07 ES350.

LexusES3505-12-06FullSizenovin.jpg?t=1300047702

LexBob2

I like those numbers better! My early build '07 (4/06) had them too.

The EPA revised their proceedure for establishing their ratings since then.

amf1932

That's why I'm bringing my car back to the dealer and get my money back!!