ES330 premium fuel

If you spring for the extra 2 or 3 bucks the next time you fill up, you can find out for yourself, which is much better than taking someone else's word for it.

Let us know what you conclude.

umm as far as i know the transmission is a closed system independent of the combustion chamber, i dont see how gasoline quality would affect the transmission.

NYLexSC; You are correct. "The transmission is a closed system independent of the combustion chamber." I'm just looking to see IF premium gas has had an effect on anyone who tried it in thier car. I am planning on trying it myself but thought I'd throw the question out to the newsgroup. Matt

View this thread: 0627>

using an octane of fuel not recommended by your owners manual in most cases will cause your engine to knock after some time despite the current modern engines that can retard the timing to counter the knocking, as well as decreased performance and decreased gas mileage overall...but i don't believe there is any link between using different gas and excess transmission wear.

The ES330 also has VVTi which will increase engine performance and fuel economy in response to the higher octane, which in turn also affects how the transmission performs.

Although the transmission is mechanically independent of the combustion chambers, they are linked electronically.

Ray O; just the person whose reply I was looking for... So as per your statement...then it IS possible for premium gas to improve the tranny lag/hesitation problem?? At almost $200/year more in cost, I want to be sure this works, especially since one of the buying points for me was a premium car that used regular gas. Thanks...

Engines with a higher compression ratio or with lots of advance on ignition timing need premium fuel. Higher compression ratios and lots if ignition timing advance generally produce more power than a similar engine with a lower compression ratio or with less advanced ignition timing. Vehicles with a distributor-less ignition system like your ES and a knock sensor can electronically reduce the amount of ignition timing advance if it detects knocking, which is how they are able to burn regular fuel instead of premium fuel.

The savings from using less expensive regualar fuel are not as great as they seem. For example, I usually use premium fuel in my LS 400, and get around

20 MPG around town. At $2.50 per gallon for premium, that is $2.50 per 20 miles, or 12.5 cents per mile for fuel. I have experimented with mid-grade fuel and get around 18.5 MPG, and at $2.40 per gallon, it costs 13.3 cents per mile for fuel. It seems counter-intuitive, but at least for my car, it actually costs less to use premium fuel than mid-grade fuel.

I have not personally experienced the transmission lag that people have complained about so I can only provide my guess about what is going on. That guess is that the "learning" part of the transmission control program places extra computational demands on the computer, and the delay is caused by the computer trying to do all the calculations and then activate the shift solenonids. If my guess is correct, then the reflash would probably be an attempt to make the code more efficient or program more default modes for the transmission under a wider number of conditions.

To answer your question as to whether it is possible for premium fuel to improve (reduce) the transmission lag, I would guess that the answer is yes for 2 reasons.

First, the transmission electronic control module (ECM) and engine ECM use some of the same information like throttle position, engine RPM, transmission output shaft RPM, engaged gear, torque converter status, individual wheel RPM, and coolant temperature. If the engine is burning premium fuel, the ignition timing would be closer to the default ignition timing and so the engine ECM does not have to make adjustments for retarded timing and the transmission ECM does not have to "wait" for results from the engine ECM.

Second, using premium fuel will produce more power for a given throttle position than with the use of lower octane fuel, and if the engine is producing more power, the transmission will not have to decide whether to downshift and take action.

Bottom line, I personally use premium fuel because it costs the same or slightly less per mile to use, with the added benefit of a more responsive engine.

I think it would be worth trying 2 or 3 consecutive tanks of premium fuel and see if the transmission lag is reduced.

The ES trans "problem", that Lexus does not recognize as a problem, has been addressed by Lexus TSBs, and the latest (At least I believe it's the latest one) trans TSB has included a note specifying premium fuel should be used.

At my last service visit the Service Advisor told me that, and I doubted it. He couldn't produce the TSB that day, and so I was virtually certain it was BS.

I have, however, since seen the TSB, and it DOES state the requirement of premium fuel. It's stated in a note on the TSB. I've yet to try several successive tanks of premium to test it. I'm just so used to telling the guy to give me "regular" over the years, It never occurs to me to say "super".

I have a ES 330, 2005 year. It has the jerk and lag. After I bought the car (new), I brought it back to the dealer for the jerk problem and they told me to drive it for about 2000 or so miles and it should improve. Something did seem to improve a bit, but I'm not sure if the car adjusted to me, or I adjusted to the car. When I bought it, they told me it's OK to use regular, so that's what I've been using. However, on a trip to Florida last year, I tried two tankfuls of premium mostly highway driving. I noticed no difference, and the mileage didn't seem to get any better (but wasn't bad - about 27 to 29 mpg. On the highway, you don't get as much lag and jerk as in slower city or suburban driving, so I really don't know if that improved with premium. I will try premium then next few tankfuls and see, but I'm not too hopeful. I took the car back to the dealer serveral months ago and complain about the continuing jerk and lag condition. I asked that they install the software update that is supposed to improve this condition somewhat. They check the car and told me that it was installed before I even took delivery of the car.

Frankly, it's not a terrible problem! If it was, I would have filed a Lemon Law claim. However, at the same time, I don't appreciate the way Lexus has handled it. They even told me that's the way the car is designed and it's supposed to run like that. "It's set exactly to factory specs." I was under the misconception that people paid extra for a Lexus mainly to avoid these kind of problems. It's sort of disappointing to realize that even with Lexus, you might not avoid those kind of problems. Frankly, my wife's

2004 4cyl. Camry runs smoother, without a jerk and lag, than my ES 330 (which is really a fancy and more expensive Camry).

In any event, I still have the car, and I'll give the premium another try. I only have about 17,500 miles on it. I can afford to give it 3 tankfuls. Hope it works. Al

"njbok" wrote in message news:C1AB9385.33BF5E% snipped-for-privacy@nospam.com...

I also owned a 2004 RX330 (which has the same platform as ES330, Camry), I experimented with 87 Octane and 89 Octane. With 87, I noticed that the responses was awful. With 89, I noticed significant difference in driving, where the engine responses better with a slight tap on the pedal and the throttle responses was awesome.

It did not noticed the same difference between 89 and 93, thus I am going to stick with 89. Did no check mpg though.

V.

---------------------------------------------------------------------------------------------------------- Al wrote:

--------------------------------

Go ahead - spring for the good stuff that costs a little more. When the speeding dump truck is bearing down on you and you are trying to get out of the way with that wonderfull hesitating tranny, it helps to know YOU did your part! At least someone did if you burn the best! Remember the Lexus motto ENGINEERING FOR SHOW, NOT GO!

With all due respect , I don't understand that . I never thought Lexus was that stylish a vehicle . I didn't think you bought a Lexus for good looks . -Dana

>

It is NOWADAYS, the new GS and IS and LS are some of the most elegant looking vehicles on the road. Lexus always built for QUALITY first and foremost, performance and looks always came second to that.

/Nick

Engineering is for show, not go. For example, the reverse looking radar to avoid collisions - only 4 sensors vs 6 on the front and a cheap little display hidden on the central dash with a nearly silent beeper. This is not well engineered for actual use. But it is there. So the engieering shows it is there, but not usefull. Hence the "for show, not go" designation. And I can quote a few more instances of that.

If you hate your Lexus so much, why don't you just get rid of it?

I concur... I asked a sensible question, and I get mostly sensible and helpful answers...and a few editorials.