Last post on Mar 16, 2011 at 6:03 PM
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Lexus ES 350, Fuel System, Sedan
#68 of 73 Fuel Type: 87 vs 91 for 2010 ES 350
Oct 27, 2010 (12:37 pm)
This is kind of a repeat of a previous question. Any input from the experts is greatly appreciated.
2010 ES 350 requires 91 octane fuel. On this forum heard some use 87 octane. Further, I understand in the 2011 ES 350 the manufacturer might recommend 87 octane. Given this:
1) Is it ok to use (from an engine perspective) 87 octane
2) How might that impact the manufacturer warranty
#69 of 73 Re: Fuel Type: 87 vs 91 for 2010 ES 350 [ansjoe]
Oct 28, 2010 (4:21 pm)
I have the same question and have a little more information but not much. The Lexus folks are telling me that the engine will compensate and should not knock but that fuel economy and performance may suffer. I'm wondering if anyone has tested the fuel economy impact.
Also, it is my understanding that what they changed in 2011 is the ECU and its software to accommodate the 87 Octane. And, no, there is no way to make that change to a 2010 car.
#70 of 73 Re: Fuel Type: 87 vs 91 for 2010 ES 350 [lucidrealty]
Nov 19, 2010 (6:59 am)
>The Lexus folks are telling me that the engine will compensate and should not
>knock but that fuel economy and performance may suffer. I'm wondering if anyone
>has tested the fuel economy impact.
As a matter of fact, I was told the same thing about my 2001 Lexus RX300. Discussing this recently with my dealer, I told him how happy I was that it ran just fine on regular unleaded. He said that the engine would compensate, but that I would get ~10% better mileage if I switched to premium unleaded.
So, I switched for 5 full tanks (the dealer told me it could take 2-3 tanks for the oxygen sensors to completely recalibrate). I ran each tank down to about 1/8 full so that I would change the fuel mix as completely as possible. I tried to not change my driving habits to the extent possible.
The result? I get better mileage with REGULAR (87 octane) unleaded than with premium (93 octane). I noticed no difference in engine sound or feel. With regular unleaded I consistently average ~19.5 mpg, but with premium I was around ~18.7. This was, as I said, over the course of 5 full tanks, or about a month.
I have since switched back to regular unleaded, and my mpg has rebounded accordingly.
So, I will stick with regular for my vehicle. But this is one of those times when I can quite literally say, "Your mileage may vary."
#71 of 73 Re: Fuel Type: 87 vs 91 for 2010 ES 350 [delegator]
Nov 19, 2010 (9:37 am)
Subsequently my mechanic told me I would need to clean some fuel device in the car periodically if I burn a lower octane gas. Not sure if I believe him.
#72 of 73 87 octane in 2008 lexus 350 ES and mpg
Dec 23, 2010 (11:29 am)
I have a 2008 Lexus 350 ES and use 87 octane gas. It runs quite well on this octane and get great milage with hway use, 30 mpg. At 70-75 mph the engine is only turning at about 2000 rpm. The engine is hardly working ! That's part of the reason you get great milage.
#73 of 73 Re: Real World Gas Mileage for a 2008 ES-350 [turbobill]
Mar 16, 2011 (6:03 pm)
You are getting great gas mileage. I get an avg of 22.0mpg and it is most city driving. With gas closing in on $4.00 a gallon for 91 Octane.... ouch