rominl

iTrader: (4)

no i wasn't specifically talking about the gs. Infamous3 talked about 50k car, 2k down/500 a month, so i am avging it out to no down monthly payment.

i don't know the ongoing lease deals on the gs but i would expect it to be between 600-700 max?

sgmstr

hmm...

this makes me wonder what Lexus puts in for you either when you get into a new car or get your service/warranty work done at the dealership.

Each dealership should at least have two gas tanks - regular and premium for different models.

SW17LS

Most dealers here actually no longer have their own tanks. The cost, insurance, environmental, etc was so high they just have agreements to fuel their cars at a gas station nearby.

I remember when I was a kid the dealers having their own pumps in the back, but those same dealers nowadays the pumps are gone.

rominl

iTrader: (4)

i thought all lexus vehicles recommend the use of premium?

SW17LS

The ES, RX & CT specify regular nowadays.

rominl

iTrader: (4)

really? wow, time has changed

SW17LS

Yup. They reduced HP figures on the ES and RX in 2011 and started specifying regular fuel.

GM11

I always use 91. Owners manual says 91 "or more". What happens when one puts in "more" than 91 then I wonder? So I pump in a tank of 93 and..... WOW!!!!

Underwhelming. There is no apparent difference in power or fuel economy, only real difference seems to be I'm 10 cents a litre poorer.

Anyone else done a proper test or persevered with higher than 91 with any success? I'm assuming there's little point but there's still this niggle: why the manual says "or more" ?

Schmexus

You're not going to "feel" any difference. Your timing *might* be slightly different, but you're most likely not going to notice any difference when accelerating.

CincyBrad

Different regions have different octane grades of fuel available. Example, here regular is 87, mid-grade is 89 and premium is 93. " Or more" is a catch all to account for these geographical differences, mostly.

mrpartsman

in CA we used to have 93 octane also until they changed it to 91, but anything is 91 or more is better, as long as u dont do 89 thats where ur knoking of the engine will start.

FishBike

The manual says "or more" because somebody at Lexus determined they would get X number of additional phone calls asking if 93 is OK too.

But seriously: octane rating is just a measure of detonation resistance. 91 is what this engine needs to run normal ignition timing without detonation. Higher octane ratings don't improve the situation because you can't have any less detonation than the "none" you get with 91. Lower rating however will require retarding the timing to avoid detonation, so 87 or 89 will cost you some power and efficiency.

Kayman

91 all the way. Had same issue with my BMW 5 series whenever I loaded up on cheap fuel my engine performance went to crap. Have to keep timing on or you will notice it.

sambb

I know the manual says to use premium, but numerous sources say it isn't necessary in most cars, if not all. They say there might be a slight performance decrease, but I don't track the car.

Is there any objective evidence of necessity in using regular or mid grade gas instead of premium?

Thanks so much for your commentary.

And let me clarify, i did do a search and there seem to be strong opinions, but I am wondering if there is objective evidence on which I could base a decision. In my previous BMWs I used the middle grade, and never had an issue.

IS340

In my experience using lower octane gas caused extended crank and poor performance in mine!! In the northwest we have poor fuel quality anyways. I switched back to Chevron premium from Costco premium, big difference no extended crank and better performance. Never used mid grade, no opinion on that. Plus with the direct injection system, did not want to compromise pump, etc.. Based on my opinion and experiencing the conditions. My two cents