Lexterious

Yes, I do know of and have read the numerous threads on the type of gas for the RX.

My question is re: the RX330 specifically and I'm looking for the official Lexus "position" on this. I'm confused by the Lexus manual's statement that Premium fuel is "recommended".

The 2004 Toyota Sienna uses the same 3.3L VVT-i engine as the RX330. Yet it is supposed to use regular.

Is there some additional tuning for the Lexus version of the engine that would make it work better if I use Premium?

I have been taught time and time again that use of a higher than the required octane in your cars gas does absolutely nothing.

And here in Canada, Premium costs 13% more than regular.

So I'd rather not pour money down the drain by using a level of gas that doesn't buy me anything?

On the otherhand, I have driven an Acura where Premium was required. There were knock sensors in the car that retarded the timing if you put in regular gas. Thus, it was detrimental (performance-wise) not to use Premium and using anything less was to be done only if you were in dire straits and no Premium was available.

If this is not the case, I'd seriously consider switching to regular.

...or continuing to use Premium BUT alter the engine computer programming to TAKE ADVANTAGE of Premium and get me another 5 or 6 HP [does anyone know how to do this?]

Does anyone know the official Lexus position on Premium vs. regular?

There some other possible advantages of using Premium. Various companies claim they put more cleaning additives into their premium than their regular. Does anyone know if this is true? Can the same effect be gotten by occasionally adding a commercial fuel injector cleaner to your tank of gas? The savings in using regular should more than cover the additional expense and perhaps the commercial additive would work better(?).

Lexmexico

I laugh whenever I read these posts. Come to Mexico where I shall extol upon you all the great benefits of never even touching regular, much less looking at it.

They sell additives here by the boatload at every Pemex station, yet all of them hurt your car just as much. I buy only Premium and put in Techron, which fortunately they sell at Costco.

And the Sienna, it is sold here, and the salespersons told me me specifically, "si usted no desea daņar su coche, utilice solamente premum." They already have a couple of cases involving Camry's getting clogged injectors. Pemex uses no additives whatsoever, and it is highly sulphuric. The only difference is the Premium is much, much cleaner.

Squid88

According to the specs, the engine has a compression ratio of 10.8 to 1. That seems very high to be running on anything less than premium. Generally any motor over 10 to 1 compression usually requires premium fuel, or the timing will have to be backed off to avoid detonation. With ignition backed off, you're not getting the most from the engine.

The HP and torque ratings are probably made by using 91 octane fuel. They want the best numbers, so they use the best fuel. I don't think you could retune the engine for premium bacause it probably already is. What they are saying is you won't ruin your motor if you use regular because the computers will adjust timing to compensate.

It's all about marketing. If you compare all the SUV's in this category (RX330, MDX, X5, ML, XC90 etc..) they all specify premium fuel, except the RX. Why? It's a selling point. "Hey, buy our SUV, it uses the cheaper fuel, you'll save money" But what they don't say, is what performace numbers you'll get with regular gas. I would love to see true HP and torque numbers with regular 87 octane.

I too am in Canada, and the extra $0.11/litre is tough to swallow if the RX truly runs efficiently on regular gas. Without performance numbers comparing 91 versus 87 it's tough to say if it's worth it. For me, I see 10.8 to 1 compression, and cringe at the thought of using regular.

Larry99

An extra 5 - 6 hp is really hard to feel.

Have an 82 Corvette and its amazing how much people will spend for that extra 5 hp, which is hardly ever noticed, even in 0-60 times - and that is at WOT.

5 hp is a 2-1/2% gain (approximately). Cost differential is, what, 15% or so.

What am I missing here.

You can build a high hp, high compression motor that will run on street gas if it is designed right.

Just my .02

o8yb

It doesn't matter if we feel that extra 5HP or not. Its what we suppose to get. If we need 91 gas to get 230HP, we shall complaint to Lexus or BBB because Lexus mislead us. If I buy a car and follow everthing they suggested, I should get what I suppose to get. I should expect getting 230 HP with 87 gas. However, on the other hand, if RX330 doesn't get better performance with better gas why they say it in the owner's manual?

Please don't get into 91 gas is better/cleaner than 87 gas debate, its pointless. if your engine don't required higher octane gas, more expensive gas will only cost you more. Now will I pump 91 gas? I will pump 91 gas during hot summer days or when my car is getting old. I know after spending $45000 on a RX, extra 20 cents per gallon on gas is nothing, but I will not waste money on thing I am not sure. I don't want to waste my hard earned money. If you really think higher octane gas is better, please pump 105 gas to your car and I beleive you car will be much faster

Again I don't think Lexus can do that, if they use better gas to get the result, I am sure some lawyers will go after them.

I guess RX330 will get 230HP on 87 gas(major/good brand gas), the timing setting for RX330 is not agressive like other sport cars so that it can run 87 gas on a 10.8 compression. They recommend to use better gas so that
1. if you use non-brand name/poor quality gas, 87 gas will not get give you 230hp, 91 may.
2. They programmed the computer to get more than 230HP if you use 91 gas

I wish #2 is true. BTW 2003 Honda Accord V6 use regular gas and get 240HP on 10:1 CR.

Sam

Squid88

The Honda Pilot gets 240hp on reg gas, but the MDX (same motor) gets 260 hp on premium. More agressive timing with better gas=more performance.

Sure you can tune an engine with a compression ratio of 10:1 to run on 87 octane, but you can bet the computer is retarding timing under stress to prevent detonation. I used to have a 92 Integra, which I originally used 87 octane. Under most conditions it ran fine, but during stress, like going up a big hill under load, it would start to ping slightly (and this is with quality Chevron 87 octane). A newer car with a computer that has the ability to retard the engine timing, would do so under load, preventing the pinging. At the point you need the full power the most, like going up the hill, the last thing I want is the computer backing off the timing (and power) when I need it most. I switched to premium and never got a ping again from that Integra.

unlike the Integra which pinged, you won't know when your RX is backing off the timing to compensate for the cheap gas, so you'll never know when your power is being robbed from you.

That Honda V6 you referred to will run on 87 in most situations, which is the way Honda likes it. Everything they do is about efficiency and durability. The masses want fuel economy, which is why they tune them for regular gas (but the computer will compensate for stressfull situations), and put ****ty tires on them that don't handle or brake well, but they last an eternity.

o8yb

That is why I will use permium gas during hot summer days or when my car is getting old. I did some research on the timing issue (not on RX but on my Miata). Agressive timing not necessary get you more HP, you may get better throttle response instead. eg Miata with 14 BTDC has higher HP than 18BTDC, but 18BTDC have noticible faster throttle response. 14BTDC does increase HP vs 10 BTDC (stock) timing but you may need better gas. May be that is what lexus referring to better performance (same HP but better response).

Again anyone work for Lexus/Toyota could clarify what better performace means in Lexus RX330 owners' manual?

Sam

tbrian

87 vs. 91 as it relates to HP don't mean jack...

Horsepower sells cars, torque wins races. Can you get the sameTORQUE from 87 as 91? If so, use it.

lspower

i hear rx330/300's all the time u can tell just by listening if they use 87oct it sounds like its going to detonate lol tick tick tick tick tick tick constantly hit the gas and ticks faster. i wouldnt use anything less then 89oct, i dont think it sounds like a timebomb if u use 89, 93 is best, its no ford escape here people??

KeysRx300

I have had my 2001 RX for almost a year. And I always use 87 octane regular. Except for 4 or 5 times this summer when only premium was available. Because of the hurricanes. When I did use premium I noticed no difference in performance.

LexFather

No, regular gas won't destroy the engine but you will get less fuel economy, knocking and less power. There is a reason PREMIUM is what they tell us to use. These are PREMINUM vehicles. We calculated the cost of savings in the GS forum once and you may save $500 a year.

You want to save gas, sign up for a RX 400H hybrid.

HarrierAWD

Read the owner's manual. If it says "premium gasoline required," then you must use premium. If it says "premium gasoline recommended," then you can use regular. You may get less power or fuel economy as 1SICKLEX pointed out, though most will hardly notice the difference in everyday driving.

With typical driving (12,000 miles a year,) you may save about $120 a year using regular gas. (Assuming average 20 MPG and 20 cents price differential.)

Ironically, the new Sienna makes 240 HPs with regular gas, while the RX330 makes 230 HPs with premium. What was Toyota thinking?

Rx900

the owner's manual, i think, says "Premium recommended" so that means you can use regular if you wish!

jaydunn

Did we get different owner's manuals? I have an RX330 purchased in Sept. of this year. My manual clearly says to use 87 octane gas OR higher.

Rx900

yeah, that's what i meant. I read that in the owners manual in one of the new loaners i got a few months ago (because i was curious on what to fill it up with). i think the "only premium" vehicles are the LS and LX, and maybe the SC (not sure)