murphysf

Hello

I just purchased a 2000 RX300 AWD.

Have read mixed messages with respect to the grade of fuel to run in the vehicle.

Should I use 87 89 or 92? I am located in the San Francisco bay area and do a 50/50 combination of highway and city driving.


Thanks!

AKBimmer

The owners manual states minimum is 87 but higher grade fuel will increase the performance. So I guess it's really personal preference. You could always try all the grades and see if you can tell a difference, and pick a grade that seems to work best for the car.

I'm probably going to use 87 for now, since it's cold and higher octane isn't as important. We only have 87. 89 and 90 here anyway and 90 is 20 cents a gallon more than 87....

hypervish

Do a search, there is so many threads on this topic you will be online reading for days and still not get an answer your heart desires.

tmic0723

I was also wondering this too. I previously had a 2002 Audi A4 1.8T and only put premium fuel in. But the first time I filled my RX300 up last week, I put in regular. With the price of gas, it's difficult to justify paying 3.80$ at the pump instead of 3.18$ when the research I've done says so many different things.

ATLs460

With any forums I frequent (Bimmer forums, Merc forums, and here) I always say....If you can afford a premium vehicle...you should be able to afford 15 more cents a gallon for better fuel.

Check www.toptiergas.com to find the absolute best gas quality near you.

salimshah

Owner manual lists the acceptable range of gasoline grade. You can try all acceptable grades and brands to find which matches best to your driving habits/pocket-book.

Salim

djchan

I've always thought you should use high octane gas for high compression engines ( for best performance). But as far as the Rx goes, you should use hi test gas to advoid excessive vibration which leads to early knock sensor failure, which doesn't sound like a simple 5 minute job.

bob2200

I have been using "regular" 87 octane in my 2002 RX300 since new. I have 128,000 miles on it. I haven't noticed any gasoline-related problems.

maxSteel

I used only regular in my 1999 RX300. I had a knock sensor fail at 227,000 miles.

I have not tested out the more expensive grades to see if the gas mileage improves enough to justify the cost difference.

Bax

My last fill up with 87 In SC was 18MPG miles\ gallons manually not the CPU . It was 1 hour or so drives to and form school in town. And that is probably with winter blend fuel.

310,000 miles. I just got the car a few months ago.

Bax

lexus114

Your not doing your Lexus any justice using the 87 octane fuel. I don't use 87 in anything, not even my lawn mowers.

maxSteel

It has been my understanding that you should use the least octane necessary to avoid engine knock. How does more octane make a difference, especially in a low compression engine like a lawn mower?

salimshah

Guys, please make your point and let the other person decide what is good.

This thread has a tendency to go out of control.

Please play nice!

Salim

kalali

It cuts the grass twice as fast....

maxSteel

Is this one of those religious war things?

I'm always willing to learn. I didn't know anything about the knock sensors. When my car started knocking recently I thought I was getting bad gas. Then I got the CEL. I also hadn't noticed until then what the manual says about using regular and possible performance loss.

The FTC said in most cases there is no benefit:
http://www.consumer.ftc.gov/articles...ctane-gasoline.

Exxon says the same thing:
http://www.exxon.com/usa-english/gfm...y_gas_faq.aspx

California energy center too (they quote the american petroleum institute)
http://www.consumerenergycenter.org/...s_premium.html

This article from the Economist is kind of schizophrenic:
http://www.economist.com/blogs/babba...octane-ratings
The author still feels he should use a higher grade, even though the article ends with: "As for those who earnestly believe (and quite a few do) that filling the family Toyota with premium will somehow make it go faster or deliver more miles to the gallon, all one can say is don’t bother. As one wit noted, the only thing it will make run faster is money from your pocket."

I did find some information that indicated two-stroke engines might benefit from it. And other information that said it could damage them.

In the end it might be best to follow the most common advice from all the articles: Use what the manufacturer recommends.