WHITEGS400

Hello everybody I am a new member of this club, and a very proud owner of a really nice Pearl White GS400.

I very much appreciate for any answers to my following question.

Is there a way for me or anyone to improve the gas mileage of a 98 GS400? I am pretty sure there isn't, but I did read on the board the following and it got me thinking "K&N - Good choice...you might even get some better gas mileage... "


please help?

Thank you, and I love this site, I practially live here now

Mr Johnson

Keep your foot off the throttle?!?

Seriously, given how hard I drive this thing I'm amazed at the mileage I do get (~17 MPG). Enjoy the car and don't worry about the mileage.

Peter

theanimala

Hell, I drive like an ahole, lots of stop and go, ALWAYS in power mode, use eshift to download a lot, and I average around 19mpg. I'm pleased.

RealMarty

WHITEGS400,

You've got a basic problem. You bought a 300 hp car and it requires fuel to run. I assume one of the reasons you bought the car is BECAUSE IT HAS 300 HP. No way to get 4-cylinder mileage from a 4.3 liter V8.

If it really concerns you then never put it into power mode and "feather foot" your driving. You know... 0-60 in 20 seconds. No late braking. No aggressive driving. No e-shift. You'll save gas. Maybe 1-2 mpg. You may also fall asleep from boredom.

OK, let's look at buying the K&N as an option. BAD IDEA if you're looking to save gas money. Figure out the cost of the K&N and divide it by what you'd save in gas. Even if you save 1 mpg -- how many years will it take to pay for the K&N with what you'll save on gas!!

Bottom line. No BS.
Figure out what that 1-2 mpg is going to save you over a year and don't spend that much on other junk. Use the $$ you'd **** away on other crap to buy the gas.

WHITEGS400

WoW you guys rule, I really appreciate your honest opinions and I totally agree with everything you all said. But, I am still truly amazed how this 300 HP Machine gets such GREAT mileage. I mean, take the gs300 and gs400, it's practically same gas mileage, rite?

Also, is there really a difference in performance of the GS400 & GS430 I know the 430 has the new 4.3 L and 400 is 4.0 - so does that mean the 430 gets more power? and also, is there a difference is fuel economy between the two models? Any other interesting facts about the GS400 that someone wishes to share with me?

I just got the car last week and still getting used to it, I guess it takes time, the drive is very smooth even on the 16's.

Thank you very much!

Presario

welcome whitegs400
Putting a K&N filter will give you better gas mileage, like realmarty said but there are other gains from changing the air filter. For example, you will get more horsepower (a little) and it will sound better, imo. So it could be something that is worth the money.

-Andy
white gs300

RacingAristo

Maybe adding SRT's intake/ecu? According to Mo, it increase 2 - 3 mpg. You get the power while having a better mpg. Not bad.

nanotech

iTrader: (2)

The K&N air filter does increase gas mileage. But like someone has said, it increases hp by a bit and I think helps the car breathe just a teeny bit better !

BUT, you can get the SRT HFI/ECU, it will let your engine breathe better, give your more hp, and you can buy it as an excuse for "increasing gas mileage". Atleast that's what I plan to tell my dad when I purchase the SRT HFI/ECU !

RacingAristo

U 2?

bitkahuna

iTrader: (20)

Welcome to the world of GS!

Yes, the 300 and 400 get the same mileage apparently, which was surprising to me.

430 has more torque than the 400, but the 430 got the 4.3 because that was what was developed for the LS430 and SC430. The 430 engine is also detuned compared to what it could do to get ULEV status.

I have a K&N drop in filter by the way, and I don't think it made any difference in gas consumption.

Math time again...

If you got 27 instead of 17 mpg, you'd save about $900 a year if you drive 20000 miles a year. That would be nice of course, but the only way you're going to get that kind of mileage is to drop about 1000 lbs of weight in the car and probably at least 100 horse power. If that's what you want, get a Camry. Otherwise, get over it. You've got a luxury car, and they're not cheap to insure, maintain, or repair.

David GS400

iTrader: (1)

The SRT HFI / ECU kit boosted my mileage considerablly on the highway. I recently drove down the the Carson Meet with a 400 plus mile round trip. I averaged around 80 -85 mph most of the time except for some stop and go traffic usually found in LA. I got 25 mpg for the whole trip. I was pretty darn happy!

Of course I'm using premium fuel. Don't make the mistake of using 89 octane thinking you're saving money. I tried that once and found that my car gets BETTER MILEAGE with premium octane than the plus type. So the extra cost for premium balances out with better mileage.

mooretorque

Welcome, WhiteGS400. Bitkahuna has summed up the issue perfectly. No data on SRT HFI/ECU here but would certainly expect gains as noted. But (large BUT), you may have warranty issues with your servicing dealer if you replace the stock intake.

The current EPA numbers on the 01 GSs are 18/23 and 18/24 for the 430 and 300, resp. This merely points up the wierd way that the EPA generates their mileage numbers but also that you can't cheat on classic Newtonian physics. The GS is a heavy car regardless of which model; it takes a lot of energy to move it which is provided in the form of fossil fuel. The motor merely converts it for you.

Driving style is the only cost free method of affecting your mileage. Drive like you've got an egg under your right foot and you'll do a little better, mileage-wise. Me, I say to hell with it. I drive how I drive depending on traffic conditions and my mood; if the red mist clouds my vision and the road's open, off we go. I've got a car that accelerates faster, goes faster, corners and stops lightyears better and gets TWICE THE MILEAGE of the '70 SS396 that I once drove. And it cossets me in luxury as well as functions as air purifier. What's not to like??? As Bit and RealMarty pointed out, if you can afford the car, you can afford the gas. Even if you could double your gas mileage, your overall cost of ownership doesn't change much per mile, since maintainence, depreciation and insurance are a much larger slice of the cost pie.

So celebrate with your right foot!!!! Again, welcome!!! Lots of information here, and lots of supportive and friendly folks - best Lexus site, period!!!

airahcaz

which octane is everyone using? never 87, but 91, 93? I would like other's thoughts if the higher octane does give you more gas mileage, thus overall better gas for the car, and not losing much $.

ripe911

Keep your windows and sunroof closed at all times on the highway will help. No more A/C either. Also, keep the stock 16" inche tires and keep them properly inflated. If you really want to save gas don't let anyone sit in the car except you. That added weight will burn more gas. Also when was the last time you went to the gym? A thin guy sitting in the driver seat will certainly help.

Seriously, don't worry too much about gas mileage. Enjoy the car for what it is: A 300hp monster. If it bothers you that much you might as well sell it and get a Camry.

airahcaz

I think plus (91 or more, maybe even 89, not 87), but don't need Premium:

http://www.exxon.com/USA-English/GFM...soline_FAQ.asp

Why should I use your premium gasoline (91-93 octane) instead of regular (87) or midgrade (89)?
Compared to our regular or midgrade, our premium is different in two ways. (1) It has a higher octane rating and, (2) it contains additional detergent additives.

(1) To find out what octane your engine needs, first check your owner's manual. The recommended level is often 87 octane. Some models have high compression engines which are designed to utilize the octane levels of 89, 91 or higher.

Ordinarily, your vehicle will not benefit from using a higher octane than is recommended in the owner's manual. But if your engine knocks or pings at the recommended octane level, you may need a higher octane gasoline to prevent the knock. Knocking may occur under certain conditions. A small percentage of vehicles may knock because of variations in engines of the same model due to manufacturing tolerances, or because of an unusual build-up of engine deposits during the first 15,000 miles of driving. Other factors such as extremely hot weather, changes in altitude or hard driving conditions (like towing a heavy load) may also cause knocking.

Many modern vehicles are equipped with an electronic device that detects and eliminates light knocking before you hear it. The devices suppress knock by retarding the spark. We believe that some of these vehicles may experience some deterioration of acceleration performance, without knocking, when operating under high engine demand conditions.

(2) Of course, our gasolines have had very effective detergents for several decades. And, because detergent additives help maintain an engine's emission performance, the EPA has required a minimum dosage in all gasolines since 1995. So, while all gasolines now contain detergents, all our gasolines contain additional quantities to better guarantee fuel system cleanliness and our 93 octane gasoline has more detergent than either of the other grades to keep your fuel injectors and intake valves even cleaner.