Why do you say that your 2000 RX 'requires' premium?

 

Lexus puts it a nicer way...They recommended it. It`s their way of saying you should use premium. I know people say; "well the Toyota Highlander has the same engine, and they recommended 87" The Lexus motors use a different ecu map.

 

In the U.S. you wouldn't have an issue running 87 octane. I can't speak for everywhere else in the world. If the only difference were octane fine, but I have been places (Mexico included) where there were other difference besides the octane (quality, sulfur content, etc.) and to this day it kind of still bothers me every time I see 87 at a station, though we have an 06 4Runner V8 that eats it just fine and gets about 17 mpg.

 

x2. Lexus doesn't want to tell you to use JUST Premium. Because, when people are shopping for a car they don't want to have to be limited to one type of gas, they might choose another car over that small difference.

And, yes exactly! The highlander has a different ecu , it's programmed differently. Same with the Camry, etc.

 

I have noticed a slight "tick" in my 05 ES330 and when it is cold and first started up it almost sounds like a knocking sound. I use the cheap gas 87. If I were to upgrade my fuel do you think this would correct the problem. My car has 120k on it and the timing belt was changed at 97k. Thanks.

 

99 RX300 AWD w/150k miles. I used to burn regular until they started putting ethonol in the fuel year round and destroying my mileage. On the advice of my gas station attendant I tried "plus" grade and noticed an immediate improvement in power and fuel economy. I then tried premium and didn't notice any addtional improvement so I have used "plus" grade ever since. I get 19mpg in the city and 25-27 on the hwy. My wifes ES330 had similar results.

 

hmm i never felt any difference in driving between each octane ratings. i also tried different gas stations and still nada . But i do get good mpg. Like 20.8-21 on city. I just do regular main and cleaned IACV and MAF and drive "properly"

 

Your experience is what all the science supports. There is no additional "power" in higher octane fuels. If your car is running fine without knocking it will not benefit from higher octane. Not my opinion, this is what the science supports.

 

There is absolutely nothing wrong with using 87 octane, I don't want spend extra money (no need to use it) .

 

Yeah keep right on believing that one.

 

some people man

 

I'm not sure what you mean by that comment. I have a 2000 that has never had anything but 87 in it from the dealership. This is what the guys at the Lexus dealership said they put in theirs and that is what I put in mine. 160K miles and still runs like it just came off the lot.

 

And if you ran the recommended fuel it would run even better. I really dont understand you guy`s, you buy a Lexus, and you want to skimp out on fuel? Why?

 

this has nothing to do with what we can afford. This is all about science. I also have an SC430 and a couple of years ago some guy said his SC rode so much better with nitrogen in the tires. This is right up there with that. I have a background in physics and engineering and you have no idea what you are talking about. I will comment no more. Over and out.

 

X2
Use premium because you want the performance, not because you engine needs it.

Why waste your money on high octane if you don't need to? I'd invest in more frequent oil and transmission fluid changes.