Toyboy300

Howzit,

I bought a '98 GS 300 recently. I'm surprised the car requires only premium gasoline. Are there any easy mods to increase gas mileage?

Thanks!

raytseng

1) don't drive as much
2) drive frugally (search the intertubes for hyper miling driving techniques)
3) keep your car properly maintained (this is not a mod, but something you should be doing anyway)

Any "mods" you think do to increase gas mileage probably will end up costing you more than what you're save in fuel(assuming the mods do anything at all in the first place).
I suggest that the only "mod" that is a fullproof plan with significant results is selling the lexus and buying a more fuel efficient method of transportation.

5t341th

iTrader: (16)

no mods.
just basic maintenance should keep your car running well.
ie. new plugs, air filter, fuel filter

eclipse604

why would you be surprised our cars take only premium fuel....
from what i know, most, if not all, luxury vehicles take premium fuel in their cars...

MrG4Life

iTrader: (14)

Fuel system treatments from either Lucas or Chevron.

UDel

I was pleasantly surprised after making the trip up North for vacation how good my gas mileage was. My first fill up my avg was 28mpg which was all highway miles and would get anywhere from 25-27mpg on the next few fillups which where also mainly highway with a little more city/stop and go. That 28 was with a packed car too. How I got the good mileage and what I recommend is.

1)Have your tires properly inflated, I had mine a little overinflated at 36psi for the trip which I think helped out alot.
2)Keep the car maintained and the maintenance up to date(clean filter, oil changed(I always use synthetic), etc.
3)I did clean my throttle body last year.
4)I also used Lucas fuel treatment on the tank before the trip.
5)Using cruise control when possible I am sure helped gas mileage.
6)DRIVE SLOWER-I avg around 55-72 instead of pushing it and going over 80 most of the way which greatly helped gas mileage.
7)I kept the windows rolled up and turned the AC off for periods of time when I did not need it and just used the fan.

I will clean the MAF soon with the CFC spray but I doubt mine is all that dirty now.

KingNasGS4

iTrader: (22)

I was just going to post this topic but I saw this one.

I have recently purchased a GS400 and my gas mileage SUCKS!
im averaging about 10 MPG in the city. this is ridiculous.

I got rid of my 93 LS400 for this?!?! (also getting about 11 MPG)
just kidding.

But i know the 98 gas mileage is supposed to be way better.
I drive with a light foot,
I have used Lucas gas treatment, the full big 13.99 bottle.

next is a tuneup (i doubt it would make much of a difference it didnt on my old car or any other lexus i know)

any other tips?

UDel

I get 16-18mpg in city/mostly stop and go driving. You should be getting better then 11mpg if you don't drive fast or accelerate hard unless you do a bunch of cold starts/runs during the day and the engine does not get a much a chance to heat up achieve optimum running temp.

A tuneup can make a big difference in some situations, check spark plugs and make sure air filter is clean and oil is good/up to date, unplug and replug battery. Keep your tires a little overinflated, clean your MAF, clean your throttle body, take excess weight out of the car, turn AC off when possible but keep windows rolled up when traveling at higher speeds, use cruise control when possible, coast when possible. Tell a trusted mechanic about your poor gas mileage and see what he says.

raytseng

Well the 93LS400 and the GS400 are both V8s, and the EPA MPG ratings is actually 1 worse in the GS400 then the LS400. So you should have expected to get slightly worse MPG with the GS than the LS for a particular drive, not way better.

http://www.fueleconomy.gov/feg/sbs.htm

If your LS400 was in proper mechanical shape too and getting 11MPG, then the 10MPG in the GS seems expected.
To change the figure, you probably need to change something else- (either something about the drive or the driver).

KingNasGS4

iTrader: (22)

man, the LS 400 SUCKED on gas.

I was driving the thing like an old lady just to see what difference it would make. nothing at all.
the tune up did little to nothing,

I changed the coolant temperature sensor. which increased power but not MPG.
I think it was just due to the age of the 93. the EPA ratings would never be accomplished with a nearly 17 year old car.

those EPA ratings suck.

I figured the GS400 MPG would be better since my friend has a 98 LS400 and the gas mileage is terrific. same engines right?
I was wrong...

AYEmike

buy a hybrid civic.

LudeNsoL

iTrader: (14)

lol yea gas mileage sucks, but its okay i love my gs

litesoarer

It's relatively easy..

Keep up on your maintenance. Keep your tire pressures a little higher than normal (i do 38-40psi on the stock 16's -- had 44psi on the 20's), oh....and Keep your foot out of it!

I managed to average 28mpg on a set of heavy 20" wheels with 225/35/ZR20 Nitto Neo-Gens, was about 75% highway at around 60mph and 25% city on a tank of 93 octane 100% Gasoline

I am currently though running a tank of the same stuff, but with the stock 16" platinum wheels, and so far have 350 miles on about 11 gallons spent (just about 32mpg), same highway/city ratio, same highway speeds

jayr0422

iTrader: (2)

Driving like an old lady to see what a difference it would make? hmmm I'm sure that lasted all of 5 minutes, lol. Sometimes people drive a little more aggressive than they realize, like when they are running late or something. There has to be something wrong with your car if your gas mileage is that low because most people are getting alot better mpg than that.

GS4_Fiend

iTrader: (22)

Driving like grandma, for example light feather the throttle all the time, especially the initial hit. Decelerate more often instead of hitting the brakes would give you better gas mileage. Aim for green lights, drive in a manner where you could hit green lights. I drive at least 50 miles everyday, 60% freeway and 40% city. I get 21-23 everytime I fill up my gas. At times when dealing with morons on the freeway sometimes I would get like 19-21 mpg.