Premium Fuel....not Good For Me

[Lexus Envy]

The second time I filled my my 90 LS400, the fuel door said "premuim fuel only". I didn't notice it on the first fill up, and got 350 mi, mostly city before the low fuel light came on.

To makle a long story short, I ran 3 high octane fillups through my car with very poor results. Never got more than 280 before the low fuel light came on. :(

I think it is because the Fuel in the premium tanks at the gas stations are old. The regular gas is fresh, anyone else have this problem?

Jimmy

[93LSOwner]

After you put in the premium, did you go back and test the regular again to see if the MPG from the last time (regular) were consistent?

[my ls430]

gas doesn't get old..and when it does get old it turns to laqur..

its been around for a million years and we use it in 50

my ls430

[Lexus Envy]

The last 2 tanks I used regular gas, and it runs great, and I am back to good mileage. Oh well, I tried.

Jimmy

BTW

Thats a very Nice Acura you have for sale, had I seen that car before I bought this one.....

[93LSOwner]

The last 2 tanks I used regular gas, and it runs great, and I am back to good mileage. Oh well, I tried.

Jimmy

BTW

Thats a very Nice Acura you have for sale, had I seen that car before I bought this one.....

Thanks for the nice words about the Acura.

Oh well, regular it is then. Whatever works out, thats all that matters. ;)

[92Lex]

Youre right about gas not getting old but if it sits long enough (3-4weeks) without any movement it'll start to seperate. Gas = hydrogen + carbon (HC). If it sits without some kind of device that "mixes" it then the hydrogen will seperate from the carbon molecule. If this happens then there will be 2 layers in that tank...Im not sure which is heavier Im assuming the hydrogen but one will sit at the bottom and the other on top of it (kind of like when you pour oil into water). Maybe you didnt get a good mix.

[SKperformance]

Ok here is a diference that may explain the problem,

reg gas is lower octane so it i easier to burn compared to premium

So you may have your timing slightly off or in need of a new cap and rotor which makes it harder to burn on top of the gas.

Check them also.

As well premium gas has better cleaners which maybe dislodging dirt causing bad milage for a bit, also how old is your plugs

[jzz30]

you can get 350 miles on a tank? :o man thats alot!!! i can only get 270 max maybe a bit more like 280- if i dont rev it as much but thats still alot.

[TallTimber]

I use the "Middle" Grade of Gasoline in my '04 LS430. It works fine. When the Gasoline Prices first went up and up, I was driving a Cadillac that was Specified "Premium Fuel Only". I asked the Dealership Service Manager what would happen if I used something other than Premium. He said a lot of People were using the "Middle" Grade with no Problems.

The Car Automatically adjusts the Timing and there's no Real Problem UNLESS you're getting Preignition (Pinging). There MAY be a slight loss of Power but, if that's True with either the Cadillac of the Lexus, it's not obvious. I was also VERY pleased with the "Mileage" on BOTH Cars.

Loss of Power? The '04 Lexus has SIX Forward Speeds. The Engine also has a LOT of Torque. I can't even imagine a situation where I would need MORE Power. Even if I hadn't put Most of my Hot-Rodding Mentality behind me, LONG ago, I would be more than pleased with the Quick Acceleration of the Lexus, and it does it SO Smoothly and SO Quietly.

[my ls430]

middle grade is just to get you to pay more for regular...but you *think* your getting something better. FYI

my ls430

[SKperformance]

look at a tanker truck when it loads new gas at a station.

Their are only 2 tanks.

Why because their is only 2 types of gas the middle is a blend of regular and premium ,in a perfect world it might be even ,with fluctuating gas prices of the oil companies do you really think you would get the best you could or just enough to satisfy the basic requirment.

[GSsoldier]

never thought of that... dang

[Lexus Envy]

you can get 350 miles on a tank?  man thats alot!!! i can only get 270 max maybe a bit more like 280- if i dont rev it as much but thats still alot.

Yes, last tank was 348 when the low fuel light came on. It comes on when there is only 4 gallons left in the tank. I use the low fuel light, and my millage trip metter to track when I need gas due to the fact my fuel gauge doesn't work correctly.

I think Premium fuel would be the best to use but I am leary of old gas, and contamenants. With gas prices the way they are now, I am afraid premium is not being bought anymore. If I lived in a very upscale part of town it might be different. You would be suprised at how much of a cheap skate the "wealthy" among us can be though :whistles: , so even if I went to the local millionares club gas station, it might not be any better.

I guess I could buy an additive for my gas, havn't checked into that though.

Jimmy

[SKperformance]

Sunoco 94 gas never sits as many performance minded owners and turbo owners won;t use anything else