LScowboyLS

premium fuel will not affect the mileage on your 2001 Corolla because it is designed for 87, its mileage is not improved by higher octane, for the reasons stated in post #253

PureDrifter

iTrader: (10)

LSCowboyLS and Python both exit this thread.
Next one of you who starts taking pot shots at the other gets a week-long suspension. I'm sick of this schoolyard crap.

RA40

iTrader: (6)

An interesting article relevant to this thread:

Part 1
http://www.autoblog.com/2014/02/19/h...nology-center/

Part 2
http://www.autoblog.com/2014/02/21/s...ier-gas-video/

jbatton

Response to LSCowboy: When I go on a trip part of the pleasure of the trip is working the numbers--mpg, miles traveled ect. When I fillup I fill all the way up into the neck to make sure I get a proper reading. I actually got 31 mpg one time on my LS400. The lowest I ever got was 25.5 but usually around 27mpg. I usually hold it around 72mph and I use the cruise when I can. I don't know if my car is unique or it is the way I drive it but I consistantly get around 20mpg in the city--no fast take offs. I had automobile dealers license for 33 years. It was mostly a hobby but it gave me the opportunity to own several thousand cars. My 97 coach edition LS400 is without a doubt the best car I ever owned. Placing the starter under the intake manifold scares me but is seems to be mostly bullet proof.

jbatton

I have been a car nut since I was a child. I am 72 years old now. I had dealers license for 33 years which enabled me to own at least a couple thousand cars. When I take a trip part of the pleasure is working the numbers--gas mileage, miles driven etc. Every tank full I top it off until a little is running out. This is to insure that I am getting an accurant check. It could be that this mileage is unique to my car but I suspect it is the way I drive. I drive for fuel economy and I just baby the Lexus. Unsually on the interstate of hold it around 72 mph and use the cruise whenever I can. In town there are no "jack rabbit" takeoffs from stop light to stop light. When I was a young guy I drove Studebaker Golden Hawks and Avanties. I got all of that out of my system. The worst mileage I ever got was in Oklahoma and New Mexico. It could be the gasoline in that part of the country. Of all the cars I have owned my 97 LS400 coach edition is the best car I ever owned.

tsarge5

I am considering purchasing a 1994 Lexus LS400 with 144000 miles that is in MINT condition.

I know the manual says you should use premium fuel but that if you have to, you can use reg. unleaded for a short time.

Would it hurt the engine if you used reg. unleaded on a reg basis?

Or would it just hurt performance, like pick up, etc.

Also, could you use Mid-grade on a reg basis?

Anyone have any thoughts on this?

Also, what kind of gas mileage should i expect, city and hwy?

Thanks!

aomdedude1

I get around 360miles per 20gal tank fill up at an $80 a tank price tag. I've used premium fuel since I bought it last summer. I also drive mostly city so that does not help the gas millage.
It is horrendous coming from a V6 Honda accord, but its a love hate thing because the car is so reliable and I absolutely love the smoothness of the ride quality.

RA40

iTrader: (6)

Welcome to Club Lexus.

The UCF 2X FAQ has many of the basic discussions about these cars.
https://www.clublexus.com/forums/ls4...questions.html

What octane gas:
https://www.clublexus.com/forums/ls4...er-thread.html

Gas mileage:
https://www.clublexus.com/forums/ls4...er-thread.html

charlesw62

I use premium exclusively. Once every six months I throw in a few gallons of 110 octane fuel but at 7.99 a gallon I use it mostly for my motorcycle

dicer

I just thought I'd add a few things to this.
1 If its in the manual, one main reason for it is for the manufacture to cover their self. And if during the warranty period, you blow the engine, and the wrong grade of fuel is found. Then they don't have to honor the warranty.
2 Since as far as I know all Lexus's have knock sensors, that covers any worries about using a lower than recommended octane fuel. As any detected knock will be dealt with via the engine control unit. And will derate the engine to accommodate the lower octane fuel.
Octane is inversely related to Cetane. The higher the Octane the harder it is for the fuel mixture to self combust under high pressure and temperature, unlike diesel fuel that desires a high Cetane, easy to self combust under those conditions. I think I saw mention some place in this thread about premium fuel burning hotter. In experiments in the past I've actually seen it run cooler. The power increase is from the ability to start the burn sooner and develop more pressure sooner. If it truly ran hotter then the detonation tendency would be higher and would require more spark retard.

stopdrpnro

my mileage suffers with 87 and 89. i use 93 and 0% ethanol when i can find it

xspsi6

iTrader: (31)

I run my 98 on 87 only no problems and average 20.5 mpg so I will continue to run 87 in it also I ran my last ls400 on nothing but 87 and not a single issue.

sushiboiii

iTrader: (1)

My parents been using 87 for the longest time in their LS and never had any issues.

peterls

That's an invitation to flame:

- How long is the "longest time"?
- What are the conditions of their driving? Do they floor it often? Never? What is their average speed?
- What are "issues"? How can anyone know that there are no issues developing as we speak? They have no means of knowing what goes on every time they put wrong octane gas in the car, but it is certain that ECU adjusts timing and everything else to compensate for the lower octane rating, giving them slightly less power, and therefore less MPG.
- And finally, if it were all the same, Lexus would not recommend we all gas up with higher octane gas. Lexus and Toyota do not sell gas, its all the same to them, except no engine runs better with lower octane gas, only worse. In the worst case, engine knock may happen (what if the knock sensors fail just as they are running low octane gas? Or what if that happens at the same time as they buy some cheap gas which is even below the stated octane rating of 87?), and they can then kiss that engine goodbye.

timmy0tool

iTrader: (7)

solomon? you better not be trolling lol! you know better.