Jump to content


Recommended Posts

Posted

which gas do you put in your rx300? Does it really have an effect on things such as fuel sensors etc going early? How about performance? does higher compression with premium fuel = more power?

I put the middle range gas in mine; seems to be fine but wondering if premium will prevent anything from breaking as early.

I know the engine is the same as the camry, so does the fuel really need to change as well?

thanks

Posted

Since gas prices are extremely high. I put midgrade for now, nothing less and make sure that has a good octane rating. Heres a good link to find out Good Gas prices and octane ratings.

http://www.utahgasprices.com/index.asp

(Change the state in the web address to were you are eg: utah to newmexico or what ever state you live in)

Posted

93 octane isn't going to do you any good in a car not designed to run on 93 octane. You should be able to use 87, try a few tanks and see if you notice any pinging or decreased performance. I use 93 also, but its not neccisary unless the car has a lot of compression, which this motor really doesn't.

Posted
which gas do you put in your rx300? Does it really have an effect on things such as fuel sensors etc going early? How about performance? does higher compression with premium fuel = more power?

I put the middle range gas in mine; seems to be fine but wondering if premium will prevent anything from breaking as early.

I know the engine is the same as the camry, so does the fuel really need to change as well?

thanks

When I purchased my RX300 the dealer recommended premium. However, after many services they "retimed" my car and the service manager recommended regular. He said if I had any problems to just give it a couple of tanks of premium and then go back to regular.

Posted

retimed?

it is controlled by the computer for advance and retarded timing not ever to me changed manually which would be by moving the timing belt one spline

Posted
which gas do you put in your rx300? Does it really have an effect on things such as fuel sensors etc going early? How about performance? does higher compression with premium fuel = more power?

I put the middle range gas in mine; seems to be fine but wondering if premium will prevent anything from breaking as early.

I know the engine is the same as the camry, so does the fuel really need to change as well?

thanks

When I purchased my RX300 the dealer recommended premium. However, after many services they "retimed" my car and the service manager recommended regular. He said if I had any problems to just give it a couple of tanks of premium and then go back to regular.

Retimed? :chairshot: Never talk to svc managers. Gary if you read this, sorry but you know I'm right. They know profit/loss on excell thats about it. You cant retime a car with no distributor. What did he tell you they did, slot the mounting holes on the coils and rotated them? Reflashed the ecu to wash out the short and long term fuel trim memory yes, retimed no. Whatever. I belive the question at hand was fuel grade and it's benefits. Look in the owners manual...probably says 89. Run name brand 89. Pemium is slightly less volitile, reduces ping in high compresion car like my IS(especialy a blown IS). It can (and does localy) cause hard start after hot soak....long cranking times after you drive 20 minutes to the store, go in for 3 minutes and attempt a restart. 87 in an 89 car MIGHT ping. Many variables here. Washington has some of the highest fuel prices in the US, and I have run chevron 91 since mile 1. I pay more than anyone I know since the old gall will no longer get 18-20 mpg with extra timing, injector durration and a 7th injector. It will not save sensors or extend thier life. You WILL have to clean your MAF every 40,000 miles. You WILL burn out a heater on O2 sensor B1S1, You WILL be plagued with evap codes, you WILL develop valve cover leaks where the #1 cam cap meets the head....

Posted

Have owned an RX since 2000. Have never run anything other than 87. If it doesn't ping on 87 don't waste your money on higher octane fuel. The extra few horsepower you MIGHT get out of the computer advancing the timing curve after input from the knock sensor really isn't worth the money. If you want a car that is faster, don't buy an RX.

Posted
Have owned an RX since 2000. Have never run anything other than 87. If it doesn't ping on 87 don't waste your money on higher octane fuel. The extra few horsepower you MIGHT get out of the computer advancing the timing curve after input from the knock sensor really isn't worth the money. If you want a car that is faster, don't buy an RX.

Many years ago I used to work for Shell Oil and was responsible for octane testing of fuels for engines in automobile, aircraft, chain saws, large trucks, etc. I found the web site below dated 7/30/2003 to be reasonable regarding octane requirements and gas mileage for engines with knock sensors.

If the Lexus engine sensors, timing, etc. are set such that no knock is sensed with 89 octane at a given load on the engine but will sense knock with any lower octane, then using a fuel with higher octane at this load will not give more power unless something is changed (e.g., the timing).

Can anyone tell me if the Lexus electronics will "advance" the timing and if so, what type of sensor is used?

http://www.usatoday.com/money/autos/2003-0...remiumgas_x.htm

Posted

Lex/toy/scion cars are not capable of timing advace (only !Removed!) unless you have a preprogamed stand alone ECU or a progamable Greddy e-man like I do. Agreed there is no gain to be had from the up-octane of a car as long as driving styles don't cause a ping. I have to envy the East Coast boys with 93 avaliable to them, but I ride in a different boat than most.

Posted
which gas do you put in your rx300? Does it really have an effect on things such as fuel sensors etc going early? How about performance? does higher compression with premium fuel = more power?

I put the middle range gas in mine; seems to be fine but wondering if premium will prevent anything from breaking as early.

I know the engine is the same as the camry, so does the fuel really need to change as well?

thanks

Owners manual says 87 and that is all I ever used in both my RXs, except for a short test to see if there was any performance or mileage advantage for a higher octane and there wasn't.

Posted

87 all the way here also, never any problems.

Jeff

Posted

well i think i'll go down to 87. I can't find ay reason to continue using mid-grade and the increase in money isn't exactly fun to pay. Thanks for the info; your saving me a lot.

Posted

I have been using 87 octane in the CPO RX300 I purchased last June and have driven 20,000 miles with no problems. I average almost 22 mpg on my 90 mile round-trip to work each day.

B.

  • 1 year later...
Posted
which gas do you put in your rx300? Does it really have an effect on things such as fuel sensors etc going early? How about performance? does higher compression with premium fuel = more power?

I put the middle range gas in mine; seems to be fine but wondering if premium will prevent anything from breaking as early.

I know the engine is the same as the camry, so does the fuel really need to change as well?

thanks

Owners manual says 87 and that is all I ever used in both my RXs, except for a short test to see if there was any performance or mileage advantage for a higher octane and there wasn't.

I was a happy 91 guy before reading all these posts made me re-think and I tried Costco 87 today. Guess what :cries: 15 miles later my CEL came on and my "very rare" IACV problem is back for good i.e. the car won't IDLE at all. I had this issue before but it was very rare and hard to reproduce so that I could not really make a claim through MBI insurance (although they cover the part)

LSS ... I think going to 87 from 91 has caused the CEL to come on and made the IACV problem worse. NTS, I will take my car to my mechanic first thing Monday :(

Anyone having similar experiences in the past and/or suggestions how to tackle this situation?

Posted

ive been using 87 octane for quite some time no and have had no problems whatsoever regarding knocking...mileage i get is also prett good..about 19 mpg on the highways...so no complaints so far..

hope this helps..


Posted
which gas do you put in your rx300? Does it really have an effect on things such as fuel sensors etc going early? How about performance? does higher compression with premium fuel = more power?

I put the middle range gas in mine; seems to be fine but wondering if premium will prevent anything from breaking as early.

I know the engine is the same as the camry, so does the fuel really need to change as well?

thanks

Owners manual says 87 and that is all I ever used in both my RXs, except for a short test to see if there was any performance or mileage advantage for a higher octane and there wasn't.

I was a happy 91 guy before reading all these posts made me re-think and I tried Costco 87 today. Guess what :cries: 15 miles later my CEL came on and my "very rare" IACV problem is back for good i.e. the car won't IDLE at all. I had this issue before but it was very rare and hard to reproduce so that I could not really make a claim through MBI insurance (although they cover the part)

LSS ... I think going to 87 from 91 has caused the CEL to come on and made the IACV problem worse. NTS, I will take my car to my mechanic first thing Monday :(

Anyone having similar experiences in the past and/or suggestions how to tackle this situation?

Does it idle when you slightly depress the accelerator?

I cannot see that the octane rating of the gasoline you use would have any impact whatsoever on the idling performance of the vehicle or the operation of the IACV.

Posted
which gas do you put in your rx300? Does it really have an effect on things such as fuel sensors etc going early? How about performance? does higher compression with premium fuel = more power?

I put the middle range gas in mine; seems to be fine but wondering if premium will prevent anything from breaking as early.

I know the engine is the same as the camry, so does the fuel really need to change as well?

thanks

Owners manual says 87 and that is all I ever used in both my RXs, except for a short test to see if there was any performance or mileage advantage for a higher octane and there wasn't.

I was a happy 91 guy before reading all these posts made me re-think and I tried Costco 87 today. Guess what :cries: 15 miles later my CEL came on and my "very rare" IACV problem is back for good i.e. the car won't IDLE at all. I had this issue before but it was very rare and hard to reproduce so that I could not really make a claim through MBI insurance (although they cover the part)

LSS ... I think going to 87 from 91 has caused the CEL to come on and made the IACV problem worse. NTS, I will take my car to my mechanic first thing Monday :(

Anyone having similar experiences in the past and/or suggestions how to tackle this situation?

Do not use Costco gas! It pretty much ruined the injectors on my Acura TL and only after extensive fuel injector cleaning is it any better. Costco just buys whatever the cheapest gas is on the market (hence their gas is cheaper) so it can be anything BP, Shell, Arco, whatever. I have heard of many problems with their gas especially with Japanese motors.

As far as the octane grade, I could be wrong but I'm pretty sure my 2001 manual calls for 91 octane in my RX300. Using a lower grade will not harm the motor, because it has knock sensors to !Removed! timing if it senses ping. It WILL affect performance and MPG which in my opinion negates the advantage of spending 10cents less per gallon if you loose 2 MPG with a lower grade. All I can say though is try a tank of premium, check MPG then try a tank of lower octane. If it works for you than fine. I'll stick with premium.

Posted

Well, Im going to try a few tanks of the Premium and see if there is any differance in MPG in my 04! I do run mid-grade all the time now cause it does make the car run better than using 87--Im positive on that.

So we will see if my MPG creeps up a few or not?? Ill let you know

Posted

Well, Im going to try a few tanks of the Premium and see if there is any differance in MPG in my 04! I do run mid-grade all the time now cause it does make the car run better than using 87--Im positive on that.

So we will see if my MPG creeps up a few or not?? Ill let you know

I use 87- have no problem get great MPG 21 - 24 average have done caculation by hand and using the NAV system. Mine is a 2004 AWD...and in owners manual it says 87 or higher...

I have used premium and notice no performance or MPG gain at all. :blink:

Posted

The tricky thing about pinging is that it can be hard to hear sometimes. I've had pinging on my car before and didn't realize it until I accelerated next to a jersey wall on the driver's side. I couldn't really hear it even if all of the windows were down if there was any traffic around me. I had to be in a quiet place that would echo.

Posted

I've been using 87 Costco in my 2000 ever since I bought it and never had a problem. I only use Costco gas in all my cars and never had any problems with any of them. I was getting 19-20 MPG until I got new tires now getting 17-18.

Jeff

Posted

I've been using 87 Costco in my 2000 ever since I bought it and never had a problem. I only use Costco gas in all my cars and never had any problems with any of them. I was getting 19-20 MPG until I got new tires now getting 17-18.

Jeff

Well hopefully you do not have a problem with Costco gas. All I can say is my wife was running it for about 1.5 years and it started have real hesitation problems. I finally took it into Acura and the service manager said there had been a sudden jump in the number of fuel injector problems in the last six months and most if not all were running Costco gas. $185 for FI cleaning later I learned my lesson...

Posted

I've been using 87 Costco in my 2000 ever since I bought it and never had a problem. I only use Costco gas in all my cars and never had any problems with any of them. I was getting 19-20 MPG until I got new tires now getting 17-18.

Jeff

I've been pumping premium gas ever since I got my car. I've stuck with mostly V-power shell or Chevron with Techron and haven't had any problems, however with the recent spike in gas prices, I am seriously considering downgrading to regular or midgrade. It costs me $65 freakin dollars to fill up last time. That's painful!!

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


×
×
  • Create New...

Forums


News


Membership


  • Unread Content
  • Members Gallery