The mileage stats I posted were from actual measured mileage and fuel pumped, not the monitor. The 26+ MPG was on trips from Wisconsin to Florida and back. I-39. I-57, I-24, and I-75. Cruse set at 70-75 mph.

The 04 RX330 calls for premium but can run on regular according to the owners manual. For the most part, for the stations I hit, the price for premium is typically 20 cents over regular. 30cents seems too high IMO. Glad I don't live in MA.

I also should point out that I did not see much difference in MPG in city driving. I did feel the difference in performance. Less downshifting and faster pick-up with premium but no better city MPG.

FWIW, BP is not a TOP TIER seller of gasoline.

 

An 05 RX330 doesn't require premium, the manual says regular. Why use premium? Studies have shown, using premium in a vehicle that doesn't require premium is just wasteful spending.

 

Per the owners manual...
As I pointed out earlier, for me, it is less expensive to use premium than to use regular.

 

A HUGE change... a 3.5 replaced the 3.3, the new 3.5 is tuned for 91 Octane. About 40 more horsepower and torque, and 1 mpg better, win win situation.

 

"the price for premium is typically 20 cents over regular. 30cents seems too high IMO"
The best price between grades is .13 that would be .26 from regular to premium and at the shell stations it is .20 from regular to mid-grade and another .10 to premium. .30 total
Most of the rest of the station here have a .14 between grades. The days of that .10 is going away very fast.

 

I was getting 91 octane at a World station but experienced hesitation. As soon as I did a fill with Shell 93, hesitation vanished. Difference between top tier and bottom tier, I suspect.

Certainly if I hear knocking or smell carbon I will switch back to 93 but a local mechanic told me should be okay as long as I keep up with the 3k mile oil changes, which I was doing pretty religiously, anyway.

 

For a motor that doesnt benefit from higher octane, yes it is a waste. I.E a chevy cavalier for example. However, the 3MZ-FE And the 1MZ-FE do benefit from using premium hence the manual stating for improved vehicle performance the use of 91 or higher is recommended.

 

So... Lexus114, you are stating definitively that the Lexus engine is different from the Camry engine - as others on this forum dispute? If that is the case, this would seal (in my opinion) the argument in favor of the higher octane.

 

The Lexus Vehicles are tuned for Premium. My Dealer service manager verified this as well.

 

I am sure we will never agree, but I don't interpret our '04 RX330 owners manual that it calls for premium.

— FUEL
Fuel type Only UNLEADED - Octane Rating 87 (Research Octane Number 91) or higher

"Select Octane Rating 87 (Research Octane Number 91) or
higher. For improved vehicle performance, the use of
premium unleaded gasoline with an Octane Rating of 91
(Research Octane Number 96) or higher is recommended."

I will have to admit, for a 230hp vehicle, you guys have amazing butt dyno's. We have tried both 91 and 85 (due to Colorado altitude), I could never tell any difference. We roll with 85 ... as usual, YMMV.

 

cdnewton - I thought I read somewhere that high altitudes do better with lower octane. Not sure why...

So far on this one tank of 87 octane i am not hearing any knocking, or experiencing any hesitation. But will be monitoring it for awhile.

 

Wait till the second tank, I dont know about the hesitation thing, but you will feel a difference.

 

Thanks, Lexus 114... will be interested to see how this goes, as the car has had 5.5 years of premium only.

 

To give it a fair test, I would reset the ECU.

 

cdnewton - I guess for the emissions and mileage re-adjust? Not sure how to do that -- is it a big deal to do, e.g., any downside risks? Thanks.