GoodRevs

Four RX's?

TorontoIS

Only premium gasoline goes into my Lexus.

Johnny

I run regular once in a while. I haven't noticed any difference in either performance or consumption. I did the same with my previous cars...

Doing this on lower end cars does make an audible difference (engine knock), but Lexus powerplant ECUs sense the change and adjust the timing accordingly.

Perfectly safe!

LexBob2

The '07-'10 ES350's recommended premium. For 2011 it's been "re-rated" for regular. Advertised hp drops from 272 to 268 which is in the same ballpark as the other Toyota models that use the non DI 3.5 V6. I wonder if they'll ever do that with the RX?

Joeb427

iTrader: (1)

The RX350 is rated at 275 HP so there might be a a slightly different tuning ,mapping or something.

LeoDLion

When not in a hurry, I would mix half and half 87 and 93 octane to get as close to 91. These are the only two octanes available around here.

socalJD

Not another 'holy war' thread - its always either regular vs premium gas or conventional vs synthetic oil and pops up in every forum every 4 months or so. Here's my take, if you plan on owning your RX for a long time, you're better served to stick w/the mfr's rec of premium or 91+ octane fuel. Primarily using 87 octane for engines 'tuned' to run 91+ will, over time, leave carbon buildup on your valves and heads, which will affect performance. The RX engine will automatically retard timing when it detects conditions that lead to pinging or knocking, but I'm not willing to save .20/gal in the short term in exchange for a future valve & head job . . .

kitlz

I assume the 4 RXs comment refers to the introduction of the 350 during the 2nd gen.

I use Shell 93 octane in mine and will not go any less. Like socal said, short term savings for potential long term repairs down the road is not a chance I care to take. Can we put this to a rest already?

LexRexBlue

I use Shell V-Power on my new RX and my 2008 IS, but regular on the '99 RX and RX400h until recently when it started not running as well. Don't know if the ethanol had something to do with it.

harleydjce

1 x rx300
1 x rx330
2 x rx350

klopez3709

I put in regular by mistake last fill-up. I won't be doing this again. Whoops!

VET4LES

My dealer told be 87 is okay and will not cause any problems. Just a few extra hp with 91.

GrandSedanFan

iTrader: (1)

My dealer told me regular is fine too, but I'm fairly heavy with the throttle and I'd really rather not put 87 in a 10.8:1 motor. Honestly, I'd rather spend the extra 5 dollars a week.

Dong99

I read somewhere (sorry do not remember where) that premium gas will get you around 10% more MPG for a high end engine like in RX, i.e. tightly tuned and with high compression ratio. I have not done the experiment myself, but this was on my to-do list. Since the the price difference between regular and premium is about 8%, I am sticking with premium for now and waiting for someone who is more scientific to do the experiment...
Frankly, I am more worried about 10% ethanol in ALL grades of gas sold in NJ than choosing regular or premium. Ethanol does not help the environment but does hurt mpg - this is pure political, both planet earth and we (tax payers) end up being the victims here.

billy44bo

The 450 has a 12.5:1 motor in it and was told buy a dealer that 89 work well with it in LA(lower Alabama) no hills on the coast.