This is taken right out of the ES350's Owners Manual on Page 394!

 

Yup, just as I said. Regular unleaded is as acceptable in the ES350 as it is as in the Camry V6. Premium fuel is only needed if you demand the best possible performance, the difference of which so far cannot be actually felt by owners who have posted about them having tried using the two grades of fuel.

 

I agree the car runs just fine with 87 octane. We have been using that for some time now. A couple of other members said they expected fewer MPG using the 87 octane fuel which could negate the savings. Has anyone been testing to see if this is true?

Several of us tested with the 2005 Avalon when it was first out and we didn't measure any significant difference in MPG between 87 or 91 octane. Of course the ES350 is using a much better tranny than the Avalon and the computer profiles must be very different.

 

I recall several posts in the past regarding putting regular 87 octane unleaded gas into the ES350. Overall i am under the impression it makes no difference in the short run. Two days ago, I was in a rush and accidentally put 87 gas into my ES350. I normally put in the 91 flavor, and this was the 1st time this car ever had anything lower since I got it last July. So far I don't feel a big difference. MAYBE slightly slower acceleration...but that could be my imagination.

Has anyone ever heard of engine damage due to lower rated gas used? I highly doubt the car will break due to one tank of 87, but I feel kinda paranoid so I want some expert advise. Thanks.

 

The ES350, Avalon, Camry, RAV4 V6's and now Sienna, all have the same engine. The ES350 is rated at 272hp on premium unleaded and Avalon/Camry @ 268 on regular unleaded. Not to worry, it won't hurt your engine to run 87 octane, you just won't get that 4hp. Premium is recommended (for the advertised hp), not required.

 

I've been running 89 in mine for the better part of a year with no issues. And my gas mileage is still 25 around town and an astounding 33 on the highway. Simply unbelievable for a car with this much power!

BTW, those are real numbers as the computer is typically optimistic by about 1.5 mpg.

 

Is 89 octane considered mid-range in your area? At the bp station I frequently use, their grades go 87, 89 and 91 octane. Just curious. I use 87 or 89. I'm satisfied with my mileage, it's running about the same as yours.

 

If you are at higher altitude, an 87 octane would be better due in part because of oxygen content/engine timing/combustion.

If the 87 octane had less sulfur content, I would be using it instead of the 92 octane I am using now at 7,000+ feet. In my case, due to high sulfur there would be damage.

With U.S. gas no worries. Keep in mind that if you switch from one octane to another, don't go back and forth stick to one.

 

What are gas prices averaging in Mexico City?

 

For the 87 octane Magna, around $2.90 USD per gallon equivalent

For the 92 octane Premium, around $3.40 USD per gallon equivalent.

 

The 87 seems pretty cheap there. It is because it has that high sulfer in it? 87 is about $3.30 or so here, with 92 generally being about 20 cents higher at about $3.50. Kind of surprising to see a 50 cents difference between 97 and 92 where you live in Mexico.

 

I get the best gas mileage when using 91 octane. My car runs sluggish on 87. And I only use TopTier Gas http://www.toptiergas.com

 

I've used all grades of fuel across 10,000 miles and have settled on 87 octane. I haven't noticed a difference in performance or mileage.

 

Same here. I'm at 20,000 miles and have used 87 octane for the last 18,000 without any performance or mileage penalty.

 

Yes, very high sulfur, well above 400 ppm minimum (Mexico City) and higher in the rest of the country.

The Premium used to be 220 ppm minimum (Mexico City), but now ranges between 30 and 80.

One time I had to use magna out in the boonies (and when I mean boonies, I mean boonies, really rural area), and a precat went on the fritz (both since removed to prevent a repeat).

Pemex is losing its output out in the big reserve it has out in the Gulf, and soon will have to find either additional deposits or use land based ones that aren't connected like one giant swimming pool, but all over the place near Tampico.

In addition, there always refinery issues and we import most our premium fron the U.S., where Mexican crude is processed in Texas.