LScowboyLS

an LS400 getting 27-30 on the highway has its A/C off and is tailgating a large semi!

dveneman

...and has 45psi tire pressure.
I just averaged 28.2 MPG on my last tank.
But it wasmosty hiway miles <75mph with no A/C.
Just cleaned TB, MAP. New CST.

LScowboyLS

yikes, that would pound my spine to death!

and I don't want to be riding in your car in an emergency braking situation on a wet road, 45psi is just asking for hydroplaning!

python

iTrader: (4)

If higher octane produced better mileage..i could go to infineon raceway which is 10 miles from my house..put in sonoco racing fuel...then put in some 104 octane boost and get awesome milage..higher octane is more stable and does affect the pre-ignition but does not produce better mileage.

PureDrifter

iTrader: (10)

You can get 12mpg on Premium and 26-28mpg on Regular in a '98-00. Driving habits and ambient conditions have a far greater effect on economy than octane.

python

iTrader: (4)

abso-friggen-lutely..correct
on a side not I am not telling anyone to run low grade or cheap gas..as a rule I never run 87..its ur money and ur car,do as u see fit.

sha4000

iTrader: (1)

When I used to make my NY to Atlanta runs I would Just put the regular in there since I would be burning all the gas in one run and I still got upwards of 460 miles before the low fuel indicator would pop up consistently. I would average 75-80 mph since I timed my trip around traffic. Never had a problem passing slower vehicles either. Other than that I generally fill up with premium and try not to go too far below half a tank for my own psychological benefits.

dveneman

This is from yesterday.
When you are this low on gas, I discovered the miles range will display "low fuel", letting you know that any more estimates are over and you are on your own..

OMAHA

does anyone know the exact fuel left in the tank when the "low fuel" light comes on? i have a '94 LS400......

python

iTrader: (4)

about 3-5 gallons?

Greg5OH

a littel off topic, but I find it hilarious how quiet the LS is when flooring it. I have the two rear mufflers removed and its still quiet accelerating. Its just a different tone, but loudness is the same. Feels like your in one of those driving sims that has the sound behind your ears. Im used to a hi compression SBF that really talks at high rpms.
Took mine for a spirited drive on a closed road to 115 mph yesterday, doesnt stop pulling, cool!

Stereorob

87 is sluggish and my 95 runs like dog**** with it. 89 is okay and thats what ive been using lately. last week i put a tank of 93 in and holy god it feels like a totally diffrent car. i can do burnouts again lol.

LScowboyLS

I average 11% better mileage with 92-93 octane vs. 87 octane, and it only costs 7% more for 92 octane at Costco vs. 87, so 11% saving vs. 7% savings, it's really a no-brainer.

I have tried until I am blue in the face to explain to some of the members here that when lower octane is used, the ECU has make adjusts to ignition timing, fuel trim and other factors to compensate for the low octane to prevent detonation (i.e. ping, knock) and after these non-optimal adjustments are made, the result is sub-optimal fuel mileage, performance and emissions quality.

Toyota didn't specify premium fuel ONLY, just for fun, it actually hurts them in cost of ownership comparisons! - I do not understand the folks who have decided that they are wiser than Toyota Engineering

that is not the way octane works, once you get the octane rating high enough to prevent detonation (knock, ping) no additional advantage is gained by increasing the octane rating

also, you are confusing the terms detonation, and pre-ignition, two very different phenomena - a certain octane cannot cause or prevent pre-ignition (aka dieseling)



here is a good book on the subject from MIT to help the good folks here at Club Lexus understand all this detonation/pre-ignition business as it relates to octane and internal combustion.

sha4000

iTrader: (1)

^^^^ I believe most people here understand what your saying.

python

iTrader: (4)

my mom lives 650 miles away..been traveling to Washington from California in my ls 400 for 7 years..back and forth..1300 miles round trip..ive used 87,89 and premium..the whole trip..both ways for SEVEN YEARS! 23 mpg avg on all grades..no knocking..no difference in mileage..if u think for one second that premium produces better mileage...then u just keep believing what u want to,blue faced or not. I have a 2001 corolla, I travel 26 miles each way to work...had the car for over year...used all 3 grades..no difference...31-33 mpg depending on conditions..driving habits..tire pressure(the biggest factor in mileage! your tires! including the brand). read up right here..this is an article from the government..who do u think im going to believe here..my own tests and everything ive read..or someone on this forum who seems to think he might know more than everyone on earth?!
http://www.consumerenergycenter.org/...s_premium.html