Joelseff

Amen Brother!!! You are Absolutely on point... I used to use regular even on my RL before I bought the Lex but after thinking about it I was only saving 4 bucks a tank.

I mean c'mon you guys, if you are sweating 4 bucks on your luxury automobile, cut back on the Grande Latte or something... i read posts here on people spending much bucks on things like car wax jeez

ZY97COACH

I live in West Texas so I am not going to complain about oil and gas prices! sorry, just cant go there. I just bought my first Lexus last month! A 97 ls400 Coach Edition, just hit 51,000 miles. I absolutely love it and am glad I didnt buy the IS that I THOUGHT I wanted. My last car was a hot lava Scion #2097 out of 2100 I believe, so I am definately at the other end of the fuel spectrum. Growing up around the whole NHRA scene I remember throwing a gallon of VP RED in my old hot rods tank with the rest being regular fuel about once a month. The Truck had a pretty mean BB454 and never seemed to have a problem burning the 105 octane leaded fuel. Although the 110 was available I was worried that I might damage my engine somehow, and my dad would have been pissed if he had caught me. I have a Drum of VP REd and am wondering if adding a half gallon in the mix would be a mistake or not. I have been buying premium and will continue to do so, I just want more!!!!! But I dont want to hurt my new toy!!!

BigManne

iTrader: (3)

93 octane Shell for me. i think i get a little better gas mileage with higher octane which equals out to be about the same as buying 87 with a little less miles to the gallon.

Lubs

I fill up with 91+ octane gas 95% of the time. The last couple of tanks I kept track of gas mileage and it clocked in at 17.8 and 18.2 mpg, so it's safe to say I get 18 mpg.

After seeing this thread I put in regular on Tuesday or Wednesday. I'm going to see how it affects my gas mileage. My first impressions with regular are the car seems a little more sluggish, but it's not terribly noticeable unless I'm really trying to push it.

I doubt I'll be putting in regular again any time soon. I just wanted to experiment for my own curiosity. If I really wanted to save a buck on gas I would be better off taking it easy on the throttle more than anything.

VipDout

iTrader: (4)

So true ...I made the mistake of pumping the Mid octane in my car at time of purchase ... and it ran really bad m, Never did that again

KRGS4

I did some testing on my GS400:

Trip: Chicago to Ohio (99% HWY Speeds)

87 octane got 442 miles 22.1 mpg ave
93 octane got 442 miles 22.2 mpg ave

Trip: City driving Chicago (99% stop and go)

87 octane 310 miles 15.5 mpg ave
93 octane 342 miles 17.1 mpg ave

* I guess on long trips with the use of Cruise it won't matter as much.

Billh2

A good example of the “Law of un-intended consequences” is the knock sensor. When these little jewels sense spark knock, they tell the computer to retard the ignition timing. Years ago, spark knock was the absolute killer of all things internal combustion. To over-simplify it, spark knock is caused by the ignition timing being excessively advanced for the load and temperature of the engine. Left to itself, spark knock turns into detonation and will destroy an engine. Knock sensors retard the timing and save our collective bacon. The engine is not as efficient or powerful. Just because the knock sensor will let us get away with lower octane fuel does not change the fact that the engine was designed to use Premium fuel. The sticker on the fuel filler door of our cars says “Unleaded Premium Fuel Only.” Using premium fuel in a car designed for regular is a waste of money. Using regular fuel in a car designed for premium fuel is being penny wise and dollar foolish.

LEXUS_KID

iTrader: (4)

use premium gas only....

Bill_GS3

That's some good info, thanks.