JorgeGVB

With tires, safety comes first for me. Michelins sound great to me too. I would never buy cheap tires.

JorgeGVB

Best quote of this thread!

All this talk about what you can or cannot afford and luxury vehicles has nothing to do with anything folks.

umpalumpa

you know 87 will work, but i usually thow a tank of 91 in my wifes rx every once in a while, or even 89. probably 30% of the time. never had a problem. i remember with my es300, 91 DEFINITELY made the car drive quieter than 87.

Bongos

Actually, I think it has everything to do with luxury vehicles... Because it is a luxury vehicle, you pay extra premium for all of the engineering, workmanship, and design that goes into a Lexus, otherwise a toyota highlander would be just fine. To each his/her own...I'll just pay for peice of mind, which in this case is about $0.30 more per gallon

CK6Speed

iTrader: (1)

You have you take my posts he quoted in context. I didn't say use the cheapest gas to save money. I said if you find there is no difference in power or MPG after using the diffrent grades of gas then use the cheapest one. That is just smart shopping. Personally, I can tell the difference and I can see the diffference in MPG, so I use Premium. Not because I have money to burn but because it makes a difference. On my 94 ES300 it makes little to no difference so I use regular.

JorgeGVB

My comment about luxury vehicles was meant in relation to using 87 to 91 octane only.

JorgeGVB

I agree with you 100%. Several of the others are interjecting their "feelings" into this topic, which has nothing to do with if it is safe to use 87 or 91 octane. If they want to think of it as buying cheap insurance or piece of mind to spend the extra money, the more power to them. But lets not pretend it something its not.

I can't recall if I read it here or on another car forum, but in tests run on this subject, the only measured difference between using the 2 grades of gas is that with some vehicles there is about 6-8 HP and as much as .5 MPG difference in performance. Most vehicles run the same on either grade. In either case, it really doesn't make much economic sense to spend the extra money on 91 octane.

If your engine runs better on 91 by all means use it, I would do the same without hesitation. However, it runs the same, it doesn't matter one way or another.

gopherhock

Personally I have encountered quite a bit of knocking when using lower grade gas. I haven't been scientific about it, but on average before switching to premium I seem to get 1-3 mpg less for city driving.

Maybe its the gas we get in Minnesota...

It *feels* like it performs better with premium... but that might just be my mind telling me I put in premium so it must translate into better performance... but hey, if that works for a few $ a month then why would I switch back.

I've spoken to a number of my more mechanically minded friends who all say to stick with the fuel recommended for a vehicle. Even putting premium in a tank not meant for premium can actually be the wrong move.

lvn098

There was an article on USA Today 10/13 regarding the ES350 (I believe this has same engine as RX350).

The article said "per user manual, 87 octane is ok, but it won't reach the maximum performance as listed, if max performance is desired, 91 should be used". The phrase is similar to that, I don't have the article right now.

cjbey

Here' what I got from Lexus Canada after repeatedly trying to pin them down on this issue:

"The warranty covers failures which are a direct result of a manufacturing defect during the warranty period as detailed in your Owner's Manual; therefore, if you do not use a gasoline that meets the requirements in your Owner's Manual and a failure occurs which can be attributed to the use of a non-recommended gasoline, this would not meet the criteria for warranty coverage."

Sounds like if a problem developes they will blame it on the gas if they can.

lvn098

Had my RX350 in for a rattle noise, a lead technician took a ride with me so I can show him what I heard.
I asked him about fuel octane, he said for an "old man style" 87 octane should be fine, but if someone who likes to "put the pedal to the floor", then 91 or higher should be used, once again, he said if pings or knocks are heard, then should go with higher octane.
About first oil change, he said just do at 5000 miles which is recommended by Lexus.

Kan-O-Z

The first point I would like to state is that I usually always see about a 10 cent difference between each grade. I don't know where these people are seeing a 30 cent difference between each grade! I have never seen that and I live in the Washington DC area which is expensive. Please be honest when making these comparisons.

I do think that if 91 is recommended, it should be used. I think it's a misconception that people think they are saving money by putting in 87 instead of 91. Lets use a simple example.
----------------------------------------------------------------
Lets say a RX does a 600 mile round trip (300 miles each way).

The first 300 miles are on 91. The RX averages 21 mpg on this part of the trip and gas costs $3.20/gallon for 91. Lets calculate total cost:

300miles / 21mpg = 14.29 gallons
$3.20/gallon X 14.29 gallons = $45.72


The next 300 miles are on 87. The RX averages 20 mpg on this part of the trip and gas costs $3.00/gallon for 87. Lets calculate total cost:

300miles / 20mpg = 15 gallons
$3.00/gallon X 15 gallons = $45.00
----------------------------------------------------------------

As you can see, there is a a whole 72 cent difference for 300 miles! This example just assumed a 1 mpg difference just to be conservative.
Some cars can see as much as a 2-3 mpg difference when using regular v. premium gas. If an RX saw a 2mpg difference, a 300 mile trip on premium 91 gas would cost $43.64 which is actually CHEAPER than regular 87 gas!!!!

So people, please be smart when deciding which grade. According to my example, you pretty much don't save money using the cheaper gas.

Here is the moral of the story:
Use the recommended premium gas! It costs the same as regular gas. It saves mother earth by using less gas. It increases the performance and efficiency of your car. It also gives you peace of mind that your engine isnt being damaged in anyway.

Please note that all of the above holds true only when a manufacturer recommends premium gas (such as the RX 350). If premium gas isn't recommended then none of this may be true.

Kan-O-Z

jfelbab

It never ceases to amaze me that people who value a quality vehicle and are willing too pay for that quality are all of a sudden so cheep when it comes to spending an extra $2-3 for a tank of gas. I mean it's not like the typical Lexus owner is in the poor house.

JorgeGVB

Kan-O-Z you put a lot of great thought into it, but I would respectfully disagree with your final conclusion. I thought you actually made a better case for using 87 octane. Since in your example your extra .72 cents really only bought you a warm fuzzy.

Not to be picky, but if I understand you right your MPG numbers are fiction and not factual. How about actually running 5 tanks of 87 and 91, and then report back on your findings? Just out of curosity I decided to do this myself, so I will report back in a month or so. However, it would likely be more helpful if several people did the same thing.

So far I have run the 5 tanks of 87 octane and just 1 tank of the 93 octane (no 91 octane in my area). Still too early to tell to be fair, but no real improvement in performance or MPG with 93 octane so far.

JorgeGVB

It has nothing to do with being cheap, if it did I would drive a Kia or and old used car. I have no problem spending money on good quality, but I can't justify it when I am getting nothing in return. With gasoline, there does not seem to be any proof at all that there is any value in buying premium gas.