Please excuse if this is a repost:

In the 2012 C&D new model preview they say this about the RX350, "the premium fuel requirement has been dropped, and an appearance package includes 19" Superchrome wheels.

The premium requirement was dropped on the 2011 ES 350.

 

My 2011 owners manual says to use premium but my salesman said it would run on regular 87 just fine. That's all I have used in 9,000 miles and it runs fine with no knocking or pinging. 25 mpg on the road.

 

yeah Lexus did that on the ES to attract buyers. I am sure they dont have to do anything to the engine since it is smart enough to know what type of fuel is in the tank and adjust automatically. This just lowers horsepower by like 5.

 

It was a matter of time. Too many competitors are recommending regular fuel for their vehicles.

 

So is it ok to run regular in a 2010? I don't think they changed anything in the engine so that the 2012 could run on regular.

 

The premium fuel recommendation was to achieve the adverstised/published hp rating. As mentioned above look for the 2012 to show 4-5 fewer hp using regular.

 

My salesman informed me to use mid grade which I did. I recently filled up with regular unleaded and noticed a drop in mpg. I was averaging 20-21 in mid grade and now I'm at 18-19 mpg in mixed driving. Car runs fine (no knocking or pinging). By the way I'm driving a 2010 RX350 AWD. I think I'll fill up with super unleaded instead get the most mpg.

 

i did the exact same thing and had exact same result. its really tempting when price goes up but I have learned my lesson and only premium as it was designed. Lexus is following suite and detuning the engine to run regular [87] on selective 2011/12 so I would still use 91+ for 10/11 models.

 

No doubt results vary by vehicle, but the EPA rates the 2010 ES350 on premium and the 2011 on regular the same 19/27 and 22 overall. It will be interesting to see what happens with the RX.

 

I currently have a 2000 RX300 (45K) and a 2011 RX450H and have previuosly owned a 2006 RX330 and a 2009 RX350. I never burned anything other than 87 octane and never had a problem.

 

My 2007 Cady V8 runs great on the recommended regular. Why do the big imports all call for hi-test?

 

You shouldn't notice a MPG change based on premium vs regular. It's probably within the margin of error, unless you hand calculated a bunch of times.

http://www.cartalk.com/content/featu...ths.html#myth1

 

I bet they still recommend it. Unless you want carbon,and cat. problems down the road.

 

We traded a 2001 RX with approximately 97,000 miles on it. The first two years we used premium gas the last eight we used regular 87. We never changed the mileage indicator and it was always between 18.5 and 20 mpg. On trips it would do much better. Never a problem with the engine of any sort.

 

I agree. Toyota has been using the non DI 3.5 V6 in about 6 different models since it came out always recommending regular fuel with no issues.