daryll40

What is the minimum octane I can get by with? I realize I probably cannot run my new '03 LS430 on 87, but am wondering what would happen if I did 89 or even a mixture of 93 and 87? I generally fill up when it gets to just above half a tank, so doing an alternating mixture would keep the result around 90 or so. Of course, if I started with a half tank of 90 octane and added 93 to full, I'd have 91.5. Then when it went to half a tank again, I'd add 87 and the result would be 89.25. Next time would be 91.125 then 89.125 then 91 .0625 then 89.0313 then.....at some point it would be about 90 octane.

Before you all start *****in' to me about driving a $58,000 car and cheaping out trying to squeeze a few buffaloes on gas...I fess up! I just HATE paying for premium gas. What can I say?

mooretorque

You can run 87 octane, at least in theory, w/o problem. Your knock sensors and engine ECU should keep any knock from occuring by retarding timing anytime knock is detected and are virtually instantaneous in their action.

You'll likely get slightly worse gas mileage (offsetting some of your cost "savings") and your V8 won't make full power since those numbers were almost certainly obtained with the 93 octane for which your motor is designed. Some folks over on the GS forum say that they feel like their V8s have not been as smooth.

Since you don't want anybody to rag you about pinching pennies, I won't. I'll merely point out that the $0.20/gal difference (average) between 87 and 93 octane works out to $200/year on the assumption of 15k miles/year at 15mpg. Gasoline costs are the LEAST significant portion of actual cost of ownership of a car in this segment. But if it makes you feel frugal, so be it. (You could, ahem, save far more by merely raising your collision deductible to, say, $1k.) Or you could take the spare and the back seats out (to save weight) and never run the A/C...................

daryll40

I already DID raise my deductible to $1000...and would go higher if the savings was significant (it's not...they won't even write it higher than $1K).

Taking the spare and rear seats out....now THERE'S an idea!


Daryll40, age 43 and more "value conscious" ("cheaper") than I've ever been...except for cars!

VQT

The computer will retard the timing so your engine won't knock, plus the car won't be as quick but do you want your car to be 0.01 second faster with premium gas by racing from stop light to stop light?
To check on the diffenence between premium and regular gas for gas mileage. Fill up with premium about three full tank and average out the mpg on your usual ravel route, then check it with regular gas. If it is no significant difference in mpg, I'll go for cheaper gas. Not just with Lexus, other cars owner like to put premium gas in their cars too. Some like Mobil some like Chevron or Texaco or 76. I can't tell the difference in performance in any of my cars on these gas.
If you're one of those owner that alway like to put the ETC on all the time and don't want anyone to pass you on any surface road, then yes put the highest Octane rating you can find. For me, I don't want to race any body. I drive my Lexus SC400 and LS400 because it nice and quiet. When I want to feel the excitement of fast acceleration, I drive a real sport car where the ride is rough, noisy because the car has no sound insulation to speak of. Lexus wasn't build for quick acceleration anyway

None of my cars has broke down because of cheap gas.

daryll40

Good reply. I guess I drive like an old man...I don't care about gaining a second from red light to red light either.

Daryll40

daryll40

It seems that VQT is saying that he runs 87 octane in his LS400 all the time. I am curious if that's safe or not?

Overclocker

a) Your question has been answered in this thread. Yes it's safe, the computer will adjust everything for you.

b) Your sig is too big by ClubLexus sig rules.

daryll40

Sorry about the big picture. While I am not a TOTAL moron, I cannot for the life of me figure out how to downsize it. Any tip would be appreciated and I'll attempt to fix the problem.

mooretorque

Daryl, it's just you. I'm 49...........

Other weight savings (and therefore mileage enhancing) ideas: remove the back doors and trunk lid. Since the seats are gone, nobody's going to be sitting back there anyway. The hood is superfluous, too, now that I think about it.

Of course, if you lose too much weight, the car WILL be that much quicker, more agile, and stop better. As Colin Chapman said, "Add lightness."

daryll40

Yeah, I know I am an cheap SOB...and sometimes pennywise but pound foolish. I'll buy the premium gas if I have to, but since I don't give a rat's derriere about performance (hey, my first car was a 6 cylinder Volare') I'd rather save the scheckels if it won't hurt the car for the 45,000 to 60,000 miles that it's likely to be mine.

Daryll40

VQT

daryll40,

Where in PA do you live? I just moved from Northeast Philly. (Bristol Township) to Vegas 5 months ago. You should see the gas price here in the West

daryll40

Pittsburgh....93 octane is $1.81 today here.

Overclocker

I don't have Photoshop here at work, but if you post this in the Photoshop forum somebody should be able to fix it.

Do you have anything like "Crazy Tuesday?" On Tuesdays, certain parts of the town have all 3 grades of gas for the same price. It's a freakin' mad house, but I get gas every Tuesday so if they don't do it one week I can skip it and get gas next week. And another tip is gas prices typically go down on Tuesday and go up on Thursday.

edit: Gas was $1.46 for me today.

daryll40

Yeah, there is a place that has premium 6 cents off on Monday's and Wednesdays. Sometimes I have to go by there, sometimes not. It's not worth going out of my way but if I have to go there anyway I'll arrange things so I can take advantage of it.

Funny, my health insurance goes up hundreds of dollars every year, yet there is nothing I can do about it so I pay. Yet to save $200 on gas, I'll bob and weave. Go figure.

Daryll40

VQT

Las Vegas gas price just came down from over $2.09 for regular before Sept. 1 to $1.79 today. Just add 10 cent for mid and 20 cent for premium gas.

Los Angeles is $2.09 still for regular.