Ls400 With Improved Gas Mileage

[mann777]

I have acheived on a full tank 517 miles on full tank that is filling 19.8 gallons of fuel. This was done when the refuelling was done at early morning. I would recommend to all to buy fuel at the coolest time of the day - early mornnig or late evening is best. During these times the gasoline is the densest, keep in mind gas pumps measure volume of gasoline not densities of fuel concentration, you are charged volume of measurement. Avoid filling to the top And never fill gas past the first click of fuel nozzle.

As said by SRK the a/c continous on has not made a considerable difference to me, i would say there was a reduction of 5% overall, I still acheived 26 mpg. Yes on the tank pre-warn amber light i have gone 33 miles to the nearest gas station. All i would say is dont over accelerate , just maintain speed , avoid jack rabbit starts and accelerate slowly when moving from dead stop. You will get peak efficiency in the fuel mileage.

[Phucanese]

i check my milage everytime i fill up the tank.

and i usually average around 19-20mpg with 60% freeway.

so my guess is that if i just drove freeway all the time, id get 23-25mpg.

cool thing is i still need to do a tune up on the car, so the milage will

be a bit better once i get off my lazy butt and do that!

with the light issue, ive noticed that it turns on when there is 4-5 gallons left.

usually around the 18gallon point. ive driven 60-70 miles with the light on before.

with 4-5 gallons left and a car that goes 20mpg, you could probably get

around 100mile on the fuel indicator light on.

[LRP_LS400]

how may gallons it is at the halfway mark? is it 10?

[931turbo]

I have a 1991 Lexus LS 400 and perhaps I need to get the spark plugs replaced because I get only about 15 or 16 m.p.g. around town and about 23 m.p.g. on the freeway. It could be the way I drive or something else.

Has anyone heard of an alternator going out in less than a year in one of these things? I got my power steering pump, alternator, and starter replaced last October, now it is the beginning of September and the damn alternator will not charge the battery. I bought a new battery, new battery terminals, and checked all connections - nothing. I know a common problem is for the power steering pump to leak fluid onto the alternator but my power steering pump is less than a year old and does not leak. I am getting frustrated because this was a brand new alternator from the dealer.

If anyone has some advice before I go buy another alternator and get it replaced, that would be greatly appreciated.

Thank you.

Tom Palmer

-Fellow Lexus Enthusiast

[OmarG]

i just got back from a long trip and i have some numbers.

24mpg over 225 miles all highway but stuck in bad traffic for about 30-45 minutes. Ac on 75-80 the whole way. Empty car. Just me.

then 28.5mpg over 335 miles ac/ off, full trunk , 55-65 whole way, sunroof open, window occasionally open. I really feathered the car to get 28 mpg. When i saw 320 miles and still half a tank left, i was proud of what i accomplished.

When I'm more aggressive with the gas i average 22-23 with ac on. Hmm is it worth it to drive like a granny?

City mpg can be as bad as 15, or as good as 22. all depends on my foot and ac... i think.

[JLP93LS]

I have a 1993 LS. I currently drive about 200 miles a day, 85% of which is on the interstate at ~ 75 mph. I average 23.5 - 24.0 mpg.

[Lst400]

I own a 2000 LS400 with a little over 194,000 miles. My daily commute in New England is roughly 150 miles round trip. My general MPG range on this commute is between 26-27. My tank average has reached 28 for some of the trips but it is never under 26 unless I'm dealing with holiday traffic. I am very pleased with my mileage.

[Keldarr]

I have a 95 LS400 with 120000 miles and had a buddy recently replace the air in my tires with nitrogen and my mpg went from 18/20 to 23/25 no joke. i put off doing it for a month thinking it wouldn't change anything but my friend finally convinced me and i have to say it works, something about the bigger molecule and less heat expansion blah blah blah it works. He said Sam's Club and Costco along with Walmart are going to be changing over to nitrogen soon for this reason. I found a Sam's club in my area that already does. ohh just a FYI if you have those paintball tanks or welding equipment with nitrogen in them don't go hooking them up to your tires w/o a regulator. My friend told me a buddy of his tried it and damn near lost his arm after he put 1800psi in his tire ^_^

[SRK]

The purpose of using nitrogen is to prevent corrosion of the wheel and degradation of the tire by removing the oxygen. Keep in mind that air is 80% nitrogen, and 20% oxygen, so using pure nitrogren is simply taking the 80% up to 100%. Not a big deal. Oxygen and nitrogen are elements, so they are atoms, not molecules, and if you look at a periodic table sometime, you'll see they are very close together, oxygen being slightly heavier.

The fuel mileage increase you claim in not the result of using nitrogen, if it is present at all. A 20% increase in mileage is more than substantial and some other factor is no doubt responsible - like mathematics.

[Keldarr]

Thanks Mr. Wizard for the science lesson, atoms are cool... Fact remains for me I was getting 18/20 MPG a month and a half ago when I last checked and now after 2 tanks with nitrogen in my tires I'm getting 23/25 MPG. With the only change done to my car being the nitrogen, and its the same route I've always taken with the same travel time as always and the same amount of leisure driving as well.

[tedhop]

Mileage on LS 400 Here in flat Indiana I get 28 mpg on the highway with ac off using hi test gas of course

[ferrarifreakout]

I live in North Carolina drive about two miles to and from, in city driving and am getting 9-12 mpg. I was getting 12mpg with a horrendously dirty air filter, changed it, and now I'm getting 9 mpg. Is there a problem? I don't have a lead foot, or at least I don't think so.

[Warhawk]

I recently purchased a '99 LS400, running around the DFW area partially on surface streets and partially on freeways, I'm getting 22/23 mpg.

On the highway I'm getting 26/27. I think it'll even do a bit better when I take really long trip with it.

[pishta]

Thanks Mr. Wizard for the science lesson, atoms are cool... Fact remains for me I was getting 18/20 MPG a month and a half ago when I last checked and now after 2 tanks with nitrogen in my tires I'm getting 23/25 MPG. With the only change done to my car being the nitrogen, and its the same route I've always taken with the same travel time as always and the same amount of leisure driving as well.

Im wondering if they finally got your tire pressure correct with the N, 9 around town sounds like my old '57 Ford Hotrod with its Predator 1 barrel.

[GKLCPA]

I'm routinely getting 20 to 21 mpg in combined city and highway driving. On the highway I'm getting 25 mpg.

Good fuel economy is one of many features I like about my LS

[Vern Dias]

Just got back from another 4500 mile trip. DFW to Denver to Billings to Salem and back to DFW via SLC.

2004 LS430. Total trip average 28.5 MPG. Using cruise control, mostly on interstates with speeds from 65 MPH to 85 MPH. Last year, I got around 30 MPG on my 98 LS 400 on the same trip.

When I started my trip, I noticed I wasn't getting very good milage (25 MPG) using premium fuel from Costco. I noticed a gradual but significant increase in fuel economy and throttle responsiveness throughout the trip. I suspect the difference may have been that I was only using Phillips, Chevron, and Shell premium gas on the trip.

When I mentioned my experience to my salesman at Park Place Lexus, he said that several of the techs there had made similar observations based on customer complaints of poor fuel economy and recommended staying away from the discount gas outlets. Particularly here in DFW where ethanol is added to the gas. I don't know if the cheaper gas is affecting the MAF and other sensors or what is happening, but I do know that there has been a significant increase in my LS430's fuel economy and throttle responsiveness during and after the trip.

I am going to stay away from the discount fuel places for the next 6 months or so and see what happens.

Vern

[Warhawk]

Just got back from another 4500 mile trip. DFW to Denver to Billings to Salem and back to DFW via SLC.

2004 LS430. Total trip average 28.5 MPG. Using cruise control, mostly on interstates with speeds from 65 MPH to 85 MPH. Last year, I got around 30 MPG on my 98 LS 400 on the same trip.

When I started my trip, I noticed I wasn't getting very good milage (25 MPG) using premium fuel from Costco. I noticed a gradual but significant increase in fuel economy and throttle responsiveness throughout the trip. I suspect the difference may have been that I was only using Phillips, Chevron, and Shell premium gas on the trip.

When I mentioned my experience to my salesman at Park Place Lexus, he said that several of the techs there had made similar observations based on customer complaints of poor fuel economy and recommended staying away from the discount gas outlets. Particularly here in DFW where ethanol is added to the gas. I don't know if the cheaper gas is affecting the MAF and other sensors or what is happening, but I do know that there has been a significant increase in my LS430's fuel economy and throttle responsiveness during and after the trip.

I am going to stay away from the discount fuel places for the next 6 months or so and see what happens.

Vern

I too am in the DFW area, I've noticed about a 10% drop in MPG with ethanol fuel, in any of our vehicles (2 Harleys, an '07 Honda CRV, an '01 Tacoma, and a '99 LS400). I've made a mental note of stations that sell ethanol and plan to avoid them. I don't believe Quik Trip has jumped on the ethanol bandwagon yet, and we buy a lot of gas from them.

[ko90ls]

I live in North Carolina drive about two miles to and from, in city driving and am getting 9-12 mpg. I was getting 12mpg with a horrendously dirty air filter, changed it, and now I'm getting 9 mpg. Is there a problem? I don't have a lead foot, or at least I don't think so.

sounds like you need some fuel injector cleaner or a tune up. 9 mpg is horrible. something is wrong under your hood. should be at lease 18-23 city-hwy.

i noticed my fuel tank lasts longer now that i have upgraded to a Injen Intake from the SC400. unfortunately my car is a 90 and doesn't display any readings like avg mpg, but i did notice that longer trips don't hit the tank like they used to! I may fill up and do some simple math to see the real Avg MPG.

[boogieman]

On a recent trip from DFW to the mountains of NW Arkansas, about 800 miles total, I got 24.5 MPG running the posted speed limits (as always) with the A/C set on auto, 32PSI(cold) in the tires, no load, and no passengers. Considering my '95 has 103,000 miles, original plugs and wires, it still runs great.

Driving locally with the heavy traffic volume here 24/7 I get around 16MPG running the A/C.