does it require premium gas
No you do not have to use Premium gas, you can use Mid-grade but never use Regular on a Luxury performance vehicle. You will get better performance and MPG's with premium gas.
having had two ES350's a 2007 and a 2012. Between the two cars i totaled 100,000 miles. I used regular gas in the car, got 31-32 miles to the gallon on highway trips (65+ mpg) and 24.7 avg on mixed driving. The car never pinged, started on first button push and made me happy every day. If it was AWD i would have a 3rd one. Always fast never hesitated and gave me a smile each day. I simply LOVED these cars. The knock sensor on the car always performed perfectly and the cars never so much had any engine or performance issues. As an engineer, frankly all the discussion is nonsense, the cars ran great. I bought regular fuel today for 1.49 gallon, Premium as 2.55 you have to be kidding if you think that is worth the extra money to make you feel a little bit better.
I can only say i bought a 2007 es350 out of the showroom and never put in regular, only premium as they reccomended and got 235500 before the torque converter went, im now in a 2012 and am a little confused as to what to use
I believe they said i should use regular but cant remember
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